Stour Estuary Trial Mussel SFO ES August12 final draft · 2 contents list of figures 3 list of...

ENVIRONMENTAL STATEMENT

IN SUPPORT OF AN APPLICATION FOR

A TRIAL SEVERAL FISHERY ORDER IN THE STOUR ESTUARY

FOR

BLUE MUSSEL MYTILUS EDULIS

Dr Siegbert Otto August 2012

‘The Old Plough’ 16 Heol y Parc Pontyberem Llanelli Carmarthenshire SA15 5EA Wales UK

Telephone: +44 (0)1269 870261Mobile: +44 (0)7791065594

E-mail: [email protected]

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CONTENTS LIST OF FIGURES 3 LIST OF TABLES 4 NON-TECHNICAL SUMMARY 5 1 INTRODUCTION 6

2 AREA OF THE PROPOSED TRIAL MUSSEL SEVERAL FISHERY ORDER 6

3 THE STOUR ESTUARY 9 3.1 PHYSICAL CHARACTERISTICS 9 3.2 RELEVANT BIOTOPES AND THEIR SENSITIVITIES AND RECOVERABILITIES 12 3.3 ORNITHOLOGY 17 3.4 FISH AND SHELLFISH 23

4 DESCRIPTION OF THE PROPOSED TRIAL MUSSEL CULTIVATION OPERATIONS 24 4.1 ACCESS 24 4.2 SETTING UP 24 4.3 SOURCING OF SEED MUSSEL 24 4.4 RELAYING OF SEED MUSSEL 25 4.5 PREDATORS AND THEIR CONTROL 25 4.6 HARVESTING 25

5 BIOSECURITY 26 5.1 BACKGROUND 26 5.2 PROPOSED BIOSECURITY MEASURES 28

6 POTENTIAL ENVIRONMENTAL EFFECTS 28 6.1 SEED MUSSEL COLLECTION 28 6.2 MUSSEL CULTIVATION AND HUSBANDRY TECHNIQUES 29 6.3 PROPOSED MANAGEMENT AND MITIGATION MEASURES 30

7 PROTECTED SITES, HABITATS AND SPECIES 35 7.1 INTRODUCTION 35 7.2 STOUR AND ORWELL ESTUARIES SPECIAL PROTECTION AREA 35 7.3 STOUR AND ORWELL ESTUARIES RAMSAR SITE 37 7.4 STOUR AND ORWELL ESTUARIES RECOMMENDED MARINE CONSERVATION ZONE 37 7.5 STOUR ESTUARY SITE OF SPECIAL SCIENTIFIC INTEREST 39 7.6 BAP HABITAT: SHELTERED MUDDY GRAVELS 43 7.7 TENTACLED LAGOON WORM ALKMARIA ROMIJNI AND STARLET SEA ANEMONE

NEMATOSTELLA VECTENSIS 44

8 STATEMENT TO INFORM A HABITATS REGULATIONS ASSESSMENT 45 8.1 BACKGROUND 45 8.2 ASSESSMENT OF POTENTIAL IMPACTS ON SPA / RAMSAR SITE INTEGRITY AND

RECOMMENDED MITIGATION MEASURES 46

9 CONSIDERATION OF ALTERNATIVES 49

10 CONCLUSIONS 52 REFERENCES 52 APPENDICES 59

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LIST OF FIGURES FIGURE 1 BATHYMETRY OF THE STOUR AND ORWELL ESTUARIES 6FIGURE 2 LOCATIONS OF THE FIVE PLOTS OF THE PROPOSED TMSFO 7FIGURE 3 BIOTOPE MAPS OF THE STOUR ESTUARY. FROM: WORSFOLD (2005). 12FIGURE 4 DISTRIBUTION AND ABUNDANCE OF CREPIDULA FORNICATA. MODIFIED

FROM WORSFOLD (2005). 14

FIGURE 5 STOUR AND ORWELL ESTUARIES LOW TIDE DISTRIBUTION MAPS FOR KEY SPECIES 2009/10.

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FIGURE 8 MAP OF HABITAT FOCI OF THE STOUR AND ORWELL RMCZ. NOTE THE MUSSEL BEDS IN HOLBROOK BAY AND UP-ESTUARY. FROM: NATURAL ENGLAND (2011).

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FIGURE 9 MAP OF THE STOUR SITE OF SPECIAL SCIENTIFIC INTEREST. FROM: NATURAL ENGLAND (2012).

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FIGURE 10 MAP OF PREFERRED SMP2 MANAGEMENT POLICY OPTIONS FOR THE STOUR AND ORWELL ESTUARIES (PRESENT DAY TO 2025). FROM: ENVIRONMENT AGENCY (2010A).

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FIGURE 11 MAP FROM “LOOKING AFTER OUR ESTUARIES - A VOLUNTARY CODE OF CONDUCT FOR USERS OF THE MUDFLATS ON THE STOUR AND ORWELL ESTUARIES” (IPSWICH BOROUGH COUNCIL, 2010).

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FIGURE 12 RECENT RESEARCH IN THE NETHERLANDS: ‘THE USE OF AN ECOSYSTEM ENGINEER IN COASTAL DEFENCE’ (FROM: WALLES ET AL., 2011).

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LIST OF TABLES TABLE 1 COORDINATES AND EXTENTS OF THE FIVE PLOTS OF THE PROPOSED TMSFO 8TABLE 2 SENSITIVITIES OF SUBLITTORAL BIOTOPES RELEVANT TO THE PROPOSED

TRIAL OF A MUSSEL SEVERAL FISHERY ORDER IN THE STOUR ESTUARY (SEE FIGURE 3). MODIFIED FROM CONNOR ET AL. (2004) AND RAYMENT (2008).

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TABLE 3 SPECIES USED TO INDICATE BIOTOPE INTOLERANCE AND RECOVERABILITY OF SUBLITTORAL AND INFRALITTORAL BIOTOPES RELEVANT TO THE PROPOSED TRIAL OF A MUSSEL SEVERAL FISHERY ORDER IN THE STOUR ESTUARY (SEE FIGURE 3). MODIFIED FROM BUD & RAYMENT (2001), BUD & HUGHES (2005), RAYMENT (2007), TYLER-WALTERS (2007 & 2008) AND BUDD (2008).

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TABLE 4 INFORMATION EXTRACTED FROM THE SEABED INDICATOR SPECIES DATABASE TO SUPPORT IMPLEMENTATION OF THE EU HABITATS AND WATER FRAMEWORK DIRECTIVES (HISCOCK ET AL., 2005).

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TABLE 5 TOTAL NUMBER OF WATERBIRDS ON THE STOUR AND ORWELL ESTUARIES 2005/06 TO 2009/10 (INCLUDES DATA FROM ALL AVAILABLE SOURCES) AND SPECIES OCCURRING IN INTERNATIONALLY IMPORTANT NUMBERS.

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TABLE 6 ESTIMATED TIMES OF EFFORT FOR THE VARIOUS ACTIVITIES ON THE FIVE MUSSEL LAYS.

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TABLE 7 POTENTIAL EFFECTS AND PROPOSED MANAGEMENT AND MITIGATION MEASURES

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TABLE 8 QUALIFYING FEATURES OF THE STOUR AND ORWELL SPA AND RAMSAR SITE, AND THE STOUR SSSI.

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TABLE 9 OPERATIONS POTENTIALLY LIKELY TO DAMAGE THE SPECIAL SCIENTIFIC INTEREST OF THE STOUR ESTUARY SSSI

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TABLE 10 SENSITIVITIES OF TENTACLED LAGOON WORM ALKMARIA ROMIJINI AND STARLET SEA ANEMONE NEMATOSTELLA VECTENSIS. MODIFIED FROM WHITE (2002) AND MARSHALL & JACKSON (2007).

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TABLE 11 ‘FAVOURABLE CONDITION TABLE’ FOR THE INTERNATIONALLY IMPORTANT POPULATIONS OF REGULARLY OCCURRING ANNEX 1 AND MIGRATORY BIRD SPECIES

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TABLE 12 WFD ASSESSMENT OF STOUR AND ORWELL SPA. FROM: ENVIRONMENT AGENCY (2009).

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NON-TECHNICAL SUMMARY This Environmental Statement (ES) was produced in support of a Trial Mussel Several Fishery Order (TMSFO) application to the Department of the Environment, Fisheries and Rural Affairs under Section 1 of the Sea Fisheries (Shellfish) Act 1967. An ES is required under the Environmental Impact Assessment Directive 85/337EC (as amended). The current proposal concerns the commercial cultivation and harvesting of a native species that occurs naturally in the Stour Estuary, Blue mussel Mytilus edulis. The application is for an exclusively subtidal bottom culture. Five plots are being applied for of between 10 and 34 ha in size, extending to a total of 84 ha. An initial trial period of five years is being applied for. Access to the area of the TMSFO, the very controlled relaying of low-density seed mussel and harvesting of the grown-out mussels will be by boat only.

The areas of the proposed TMSFO lie wholly within the Stour and Orwell Estuaries Special Protection Area (SPA), designated for its ornithological interests. The Stour Estuary Site of Special Scientific Interest (SSSI) ‘underpins’ the SPA in this area. The Stour and Orwell Estuaries are also part of a recommended Marine Conservation Zone, put forward in part because of the presence of very small, natural mussel beds, foremost in the Stour Estuary. Nationally scarce brackish water species, the Starlet sea anemone Nematostella vectensis and the Tentacled lagoon worm Alkmaria romijini, are also being considered here, in addition to a Biodiversity Action Plan (BAP) priority habitat (‘Sheltered muddy gravels’) and a BAP priority biotope, dominated by the invasive, non-native Slipper limpet Crepidula fornicata. Potential adverse impacts have been identified, including (a) disturbance and damage to sensitive intertidal and subtidal habitats; (b) disturbance and displacement of waders and wildfowl; (c) introduction of non-native species and pathogens; (d) nutrient enrichment; (e) attraction of epifaunal predator species and their control; and (f) possible long-term changes to hydrodynamics and associated sediment processes, to name but six areas of potential impacts. Juxtaposed to the aforementioned, detailed measures and conditions have been identified and formulated, that will avoid, reduce and mitigate significant adverse effects. These include strict controls on means of access, timing, extent and intensity of operations. Alternative locations for subtidal and intertidal mussel bottom culture have also been considered. However, sheltered areas suitable for the commercial cultivation of mussels are very limited along the coast of East Anglia and there are further constraints imposed by bird conservation interests in many intertidal areas. Overall, this Environmental Statement demonstrates that the current proposal will result in an environmentally benign mussel fishery, whilst possibly even enhancing some subtidal biotopes by way of the regular removal of Slipper limpet Crepidula fornicata from almost 10 % of the subtidal area of the Stour Estuary. A statement, akin to a Test of Likely Significant Effect, to inform any Appropriate Assessment under Regulation 61 of The Conservation of Habitats and Species Regulations 2010 (as amended), has also been included.

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1 INTRODUCTION This Environmental Statement (ES) was produced in support of a Trial Mussel Several Fishery Order (TMSFO) application to the Department of the Environment, Fisheries and Rural Affairs under Section 1 of the Sea Fisheries (Shellfish) Act 1967. An ES is required under the Environmental Impact Assessment Directive 85/337EC (as amended). The current proposal concerns the commercial cultivation and harvesting of a native species that occurs naturally in the Stour Estuary, Blue mussel Mytilus edulis. The application is for an exclusively subtidal bottom culture. Five plots are being applied for of between 10 and 34 ha in size, extending to a total of 84 ha. An initial trial period of five years is being applied for. The areas of the proposed TMSFO lie wholly within the Stour and Orwell Estuaries Special Protection Area (SPA), designated for its ornithological interests. The Stour Estuary Site of Special Scientific Interest (SSSI) ‘underpins’ the SPA in this area. The Stour and Orwell Estuaries are also part of a recommended Marine Conservation Zone, put forward in part because of the presence of very small, natural mussel beds, foremost in the Stour Estuary. Nationally scarce brackish water species, the Starlet sea anemone Nematostella vectensis and the Tentacled lagoon worm Alkmaria romijini, are also being considered here, in addition to a Biodiversity Action Plan (BAP) priority habitat (‘Sheltered muddy gravels’) and a BAP priority biotope, dominated by the invasive, non-native Slipper limpet Crepidula fornicata. 2 AREA OF THE PROPOSED TRIAL MUSSEL SEVERAL FISHERY ORDER

The area of the proposed TMSFO lies entirely within the subtidal zone of the Stour Estuary (Figure 1).

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Figure 1 Bathymetry of the Stour and Orwell Estuaries

Figure 2 Locations of the five plots of the proposed TMSFO The coordinates for the five plots are listed in Table 1. There is a need for the space provided by five plots to relay seed mussel, because (a) relaying will be at a low density, and (b) by the time they become half grown mussels they need to be re-laid in another plot to grow out and reach a good yield inside. Applying a mussel culture with separate lays for seed-, half grown and fully grown mussels provides for better returns.

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Table 1 Coordinates and extents of the five plots of the proposed TMSFO

Waypoint Latitude Longitude

NW 51.572004 001.137929 N1 51.572877 001.141406 N2 51.573082 001.150092 NE 51.572746 001.153207 SE 51.571703 001.153233 S1 51.571572 001.147980 S2 51.572248 001.147980 S3 51.572068 001.141448 S4 51.571396 001.141448

SW 51.571332 001.137929 Plot 1 - 34 ha

NW 51.569117 001.127913 NE 51.569171 001.133200 SE 51.568091 001.133234 SW 51.568037 001.127964

Plot 2 - 12 ha

NW 51.572769 001.106241 NE 51.572013 001.116703 SE 51.571213 001.116540 SW 51.571947 001.106095

Plot 3 - 18 ha

NW 51.570548 001.107974 NE 51.569884 001.107734 SE 51.569611 001.114815 SW 51.568949 001.114592

Plot 4 - 10 ha

NW 51.571111 001.083925 NE 51.571093 001.088311 SE 51.570005 001.088302 SW 51.570029 001.083916

Plot 5 - 10 ha

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3 THE STOUR ESTUARY 3.1 PHYSICAL CHARACTERISTICS The Stour is a long and straight estuary, which forms the eastern end of the border between Suffolk and Essex. The estuary's mouth converges with that of the Orwell, which extends from Ipswich to Felixstowe, as the two rivers enter the North Sea. The Stour Estuary covers an area of 26.5 km2. Measurements from the latest Admiralty Charts and a 1999 survey indicate that about 17.5 km2

of this area is intertidal (above CD) and the remaining 9 km2

subtidal. Analysis of aerial photographs from 1997 (University of Newcastle, 2000) showed that of the 17.5 km2

of intertidal area, the saltmarsh area accounts for 1.07 km2. The navigation channel varies from a depth of –9.0 m CD (up to Harwich International Port) to -0.4 m CD at Mistley. The LW channel is approximately 120-150 m wide as far as Wrabness. Further upstream the LW channel decreases in width, becoming less than 30 m wide at Mistley. The area of intertidal flats is extensive and is separated into bays by outcrops (or Nesses). The principal bays are Seafield, Holbrook and Erwarton Bay on the northern shore and Copperas and Bathside Bay on the southern shore. Holbrook Bay is the largest expanse of intertidal flat being some 1.5 km wide with an approximate slope of 1:500 (based on bathymetric surveys of the low-mid parts of the bay, i.e. excluding any saltmarsh areas) (Royal Haskoning, 2003). Erwarton Bay has an intertidal flat up to 500 m wide with an approximate slope of 1:300. Copperas Bay is up to 800 m wide with an approximate slope of 1:500 m. Bathside Bay is up to 750m wide with an approximate slope of 1:300 m. Seafield Bay is up to 1.2 km wide with a very varying slope of on average about 1:500. Above HW neaps saltmarsh exists along the entire length of the Estuary as far downstream as Parkeston Quay and as far upstream as Manningtree. The width of saltmarsh area is largely between 50 and 100 m but in Seafield Bay, the east part of Copperas Bay and the west part of Erwarton Bay, the saltmarsh is more extensive with depths of up to 200 m, up to 600 m and up to 300 m respectively. The saltmarsh in Seafield Bay is backed by seawall and embankment as is saltmarsh on the west side of Holbrook Bay. On the south shore east of Mistley there is a 1 km stretch of saltmarsh backed by cliffs about 18 m high. The Stour Estuary is an ebb-dominant estuary, having stronger ebb currents than flood currents and a longer LW slack than HW slack which both promote the export of sediment. The effect of local wind-induced waves also promotes export of sediment by causing the re-suspension of material from the intertidal areas around HW so that it can be carried downstream by the stronger ebb tides currents. However, at its head (landward of Mistley) the estuary is flood-dominant and therefore this part of the estuary tends to act as a sink for any fine sediment that progresses this far upstream. This stretch is therefore characterised by muddy sediment. Further downstream the channel bed becomes progressively sandier with patches of gravel. Intertidal areas are mostly muddy but contain high proportions of sands, shells and gravel. Throughout much of the estuary downstream of Stutton Ness, the intertidal areas adjacent to the channel stand proud of the intertidal areas further landward. This is assumed to be associated with the gravel extraction between 1968 and 1973 rather than a result of natural estuarine processes (Royal Haskoning, 2003). Coring in these areas of accumulation has demonstrated that the accumulation is of fine material (HR Wallingford, 2001a). Given the disturbance that the historical gravel extraction has caused it is difficult to interpret the present day distribution of bed forms and material type in the Stour.

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Comparison of the surveys between 1965 and 1982 reveals interesting information on the major morphological changes within the estuary associated with the historical gravel extraction even when potential inaccuracies between the two surveys are considered. However, it is not possible to undertake a comparison for the entire estuary and as such it is only possible to identify removal of about 2.0-2.5M m3

of material from the low water channel. An apparent accretion of about 1M m3

is observed over the period above CD between Mistley and Copperas Wood, which must be associated with the redistribution of run-off of fine material during the winning of gravel. The greatest supply of sediment to the Stour is from offshore, passing through the Harbour on the flood tide. The flux of fluvial sediment is small and therefore concentrations increase with distance seawards from the head of the Estuary. The much higher concentrations brought in on the flood tide (promoting import of sediment) are balanced by the ebb-dominant current speeds of the estuary (promoting export of sediment). Wave events cause resuspension of material from the intertidal areas which tends to be redistributed within the estuary or to pass out of the estuary on the ebb tide. Measurements of spring tide suspended sediment concentrations in the Stour vary from peak values of over 1000 mg/l at Parkeston (measured near the bed at peak ebb of a large spring tide) to values of 6-20 mg/l near Stutton Mill (from water samples). Neap tide measurements vary from 20-70 mg/l at Shotley Gate to values of 4-9 mg/l near Stutton Mill (HR Wallingford, 2001b&c). The estuary has been experiencing the erosion of intertidal areas since the 1920’s when much of the prevalent Zostera (eelgrass) population, which had a binding effect on sediment, died off. It has been estimated that between 1925 and 1965 more than 20M m3

of material has been eroded from the intertidal areas of the Stour (Royal Haskoning, 2003). At a steady rate, this represents erosion of about 500,000 m3/year, and is broadly equivalent to an average vertical rate of erosion of around 20 mm/year. Beardall et al. (1991) quote an estimate of 15M m3

of net erosion over the entire Stour-Orwell system between 1925 and 1965 which is derived from the same analysis. The erosion of intertidal areas from within the Stour is ongoing, but at a lower rate to that estimated for the period 1925-1965. Based on an analysis of the bed changes between 1994 and 1999 the present erosion rate is about 13 mm/year for the intertidal mudflat area above CD. The area of the intertidal mudflats in the Stour is presently estimated at 17.5M m2

and the average volume eroded per year is estimated to be 240,000 m3/year for the period 1994 to 1999. The observations for this period demonstrate that the erosion appears to be greater along the lower part of the intertidal profile. The present rate of loss of saltmarsh in the Stour Estuary is estimated to be of the order of 2 ha/year and the rate of loss appears to be slowing down (HR Wallingford, 2001d). This idea of a reduction in loss rate is supported by historic measurements described in Smith (1986) indicating that the rate of retreat of saltmarsh cliffs in Copperas Bay was 30 mm per month over a nine month period in 1975/76 (equivalent to 0.4 m/year) and in Erwarton Bay over the period 1976-1991 as much as 50 m of saltmarsh was lost (equivalent to about 3 m/year). The measurements in Copperas Bay for the period 1975/76 also indicated that in a 17 month period the surface level of the marsh fell by 20 mm (equivalent to about 14 mm/year). Most waves in the lower Stour Estuary are due to local generation by the wind over the restricted fetches although waves from offshore can propagate into the lower Stour Estuary. Changes within the Harbour and approaches have modified wave energy in this area (HR Wallingford, 2001e). Waves in the Stour have typical wave heights of the order of 0.2-0.3 m

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although strong westerly winds can generate waves in excess of 1 m in height throughout much of the estuary (HR Wallingford, 1994). The gradual erosion within the Stour Estuary has meant that fetch lengths have increased and waves can break closer to the high water mark: consequently during westerly storms wave action in the lower estuary at the eastern end of Erwarton Bay, has increased. The largest waves typically occur at or shortly after high water when winds are able to generate waves over the longest fetches. The tidal range in the Stour increases over the length of the estuary with the mean spring range at Harwich being 3.6 m (0.4 to 4.0 m CD) while that at Mistley is 3.9 m (0.3 to 4.2 m CD). Similarly the mean neap tidal range at Harwich is 2.3 m (1.1 to 3.4 m CD) while that at Mistley is 2.4 m (1.0 to 3.4 m CD). Chart Datum for the Stour up to Mistley is defined as 2.02 metres below OD. At the mouth of the Stour (Shotley Gate), the peak flood and ebb currents occur just before and just after HW. With distance upstream the magnitude of the flood current speed just before HW decreases relative to the other, earlier flood tide peak and the time of peak ebb current occur later in the tide. Peak current speeds at Shotley Gate for a mean spring tide are 1 m/s during the ebb tide and 0.7m/s during the flood. Peak currents for a mean neap tide are 0.7 m/s (ebb) and 0.5 m/s (flood). For most of the length of the Stour, ebb current speeds are greater than flood current speeds, both decreasing in magnitude with distance upstream. However this changes near the head of the estuary at Manningtree where peak flood currents become faster than those occurring at peak ebb. This is as a result of the cumulative effects of friction on the propagating tidal wave, which cause the crest of the flooding tidal wave to travel upstream more quickly than its trough. This results in an increasingly shortened flood tide and an increase in flood current speed over that of ebb currents. Throughout the Stour the low water slack period is longer than the high water slack period. The freshwater flow characteristics in the Stour at Langham between January 1963 and June 2001 were as follows: maximum flow was 50.0 m3/s, minimum flow 0.1 m3/s and the mean flow was 3.0 m3/s. The catchment area of the River Stour covered by this monitoring station is 578 km2. Further flow records from about 3 km further downstream, approximately 6 km upstream of Manningtree for the period 1978 to 1991 gave a slightly higher mean freshwater flow of 3.5 m3/s. The Stour, therefore, has a relatively small fluvial discharge compared with the tidal discharge entering the Harbour (peak discharge is approximately 10,000 m3/s on a flood tide). As a result salinity levels are not generally influenced by freshwater except near the head of the estuary. Spring tide observations in 1991 showed salinities greater than 19 ppt throughout the tide at Manningtree, and most of the estuary is well mixed. However, there is evidence that under periods of high and prolonged freshwater flows the estuary can exhibit vertical salinity gradients. Measurements of salinity in February 2001 during a period of unusually high river flows showed variations of more than 4 ppt between the surface and bed in the lower Stour (HR Wallingford, 2001f). Analysis of the freshwater gauging data showed that the average daily flow for January and February 2001 (23.7 m3/s) was greater than that for any other year since 1963. The resulting stratification produces an increase in the near bed current speeds on the early flood tide (HR Wallingford, 2001g).

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3.2 RELEVANT BIOTOPES AND THEIR SENSITIVITIES AND RECOVERABILITIES ‘Biotope’ refers to the combination of the physical environment (habitat) and its distinctive assemblage of conspicuous species. For practical reasons of interpretation of terms used in directives, statutes and conventions, in some documents, ‘biotope’ is sometimes synonymized with ‘habitat’. ‘Habitat’ is the place in which a plant or animal lives. It is defined for the marine environment according to geographical location, physiographic features and the physical and chemical environment (including salinity, wave exposure, strength of tidal streams, geology, biological zone, substratum), ‘features’ (such as crevices, overhangs, or rockpools) and ‘modifiers’ (for example sand-scour, wave-surge, or substratum mobility). ‘Community’ refers to a group of organisms occurring in a particular environment, presumably interacting with each other and with the environment, and identifiable by means of ecological survey from other groups. The community is usually considered the biotic element of a biotope.

LEGEND

Figure 3

Biotope maps of the Stour Estuary. From: Worsfold (2005).

The following sublittoral biotopes are of direct relevance to the proposed locations of the trial mussel lays:

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Substrate predominantly classified as the biotopes SS.SMu.SMuVS.AphTubi (Aphelochaeta marioni and Tubificoides spp. in variable salinity infralittoral mud) (Plots 1 to 5) and SS.SMx.SMxVS.CreMed (Crepidula fornicata and Mediomastus fragilis in variable salinity infralittoral mixed sediment) (Connor et al., 2004) / SS.IMX.EstMx.CreAph (Crepidula fornicata and Aphelochaeta marioni in variable salinity infralittoral mixed sediment) (Connor et al., 1997) (Plots 3 and 5) are proposed to be used for the mussel lays (cf. Figures 2 and 3). Only Plots 2 and 4 encroach on the biotope SS.SMx.SMxVS.AphPol (Polydora ciliata, Mya truncata and solitary ascidians in variable salinity infralittoral mixed sediment). The proposed mussel lay locations will otherwise avoid sublittoral mixed sediment biotopes, such as SS.SMx.IMx.SpavSpAn (Sabella pavonina with sponges and anemones on infralittoral mixed sediment), for instance. Crepidula fornicata and Mediomastus fragilis in variable salinity infralittoral mixed sediment [SS.SMx.SMxVS.CreMed (Connor et al., 2004)] Variable salinity mixed sediment characterised by the slipper limpet Crepidula fornicata and the polychaetes Mediomastus fragilis and Aphelochaeta marioni. Other numerically important taxa include the oligochaetes Tubificoides benedii, syllids such as Exogone naidina and Sphaerosyllis, and Nephtys hombergii. Lepidonotus squamatus and Scoloplos armiger may also be common. Shell debris and cobbles are colonised by the ascidians Ascidiella aspersa, Ascidiella scabra, Molgula sp. and Dendrodoa grossularia (the ascidians may not be recorded adequately by remote infaunal survey techniques). This biotope occurs in the lower estuary where currents allow a stable environment to develop. It is associated with oyster beds and relict oyster beds (.Ost) in southern England and Wales. It may be found adjacent to or in conjunction with AphTubi and AphPol. An earlier classification (Connor et al., 1997) describes this biotope, formerly known as SS.IMX.EstMx.CreAph, as follows: Variable salinity mixed sediment characterized by the slipper limpet Crepidula fornicata and the polychaete Aphelochaeta marioni. Shell debris and cobbles are colonized by the ascidians Ascidiella aspersa, Ascidiella scabra, Molgula sp. and Dendrodoa grossularia (the ascidians may not be recorded adequately by remote infaunal survey techniques). This biotope occurs in the lower estuary where currents allow a stable environment to develop. It is associated with oyster beds and relict oyster beds (IMX.Ost), in southern England and Wales, separated from these by the superabundance of Crepidula fornicata. It may be found adjacent to or in conjunction with IMU.AphTub, again separated by the abundance of Crepidula fornicata and its sediment characteristics. It may be associated with IMX.VsenMtru and possibly forms a component of SCR.Aasp. Worsfold (2005) reported that several dredge and trawl hauls from the estuaries had large numbers of Slipper limpets Crepidula fornicata. They colonised small stones that lay over mud inhabited by worms typical of the surrounding mud habitats. The stones also supported epifauna such as anemones (mostly Sagartia troglodytes and Sargartiogeton undatus) and the bryozoa Bowerbankia spp. and Anguinella palmata. Such areas were assigned to SS.SMx.SMxVS.CreMed as typical examples of the biotopes. The biotope was distributed in patches along the sides of the channel of both estuaries, but particularly the mid Stour. The mussel lays will attract Slipper limpets from a wider area of the estuary and will regularly removed by way of harvesting the mussels and cleaning the plots. Consequently a wider area of the estuary would benefit from the mussel cultivation.

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Figure 4 Distribution and abundance of Crepidula fornicata. Modified from Worsfold (2005). Aphelochaeta marioni and Tubificoides spp. in variable salinity infralittoral mud [SS.SMu.SMuVS.AphTubi] (Connor et al., 2004) Variable salinity cohesive muddy sediment (sometimes with some coarser material) dominated by the polychaete Aphelochaeta marioni (or other Aphelochaeta species, e.g. A. amplivasatus) and the oligochaete Tubificoides spp. These taxa are generally accompanied by Nephtys hombergii whilst the polychaetes Capitella capitata and Melinna palmata may also occur in high numbers in some areas. Other members of the cirratulid polychaete group e.g. Caulleriella zetlandica. and Tharyx spp. may also occur in high numbers, sometimes replacing A. marioni as the dominant polychaete. However, there is still inconsistency in the identification of the cirratulid group which is further compounded by fragmentation during sample processing. This biotope is very common in stable muddy environments and may extend from reduced salinity to fully marine conditions. This is one of the principal subtidal biotopes of the estuaries, as identified by cluster analysis (Group B) (Worsfeld, 2005). Most of the fauna from the sediment grab samples recorded in previous surveys (see Dyer, 2000a) was referred to the equivalent of this biotope in the old classification (IMU.AphTub Aphelochaeta marioni and Tubificoides spp. in variable salinity infralittoral soft mud). July 2002 dredge samples containing mud or muddy mixed sediment were assumed to belong to it. Most samples were typical of the described biotope. Certain areas proved to contain more gravel and overlap with IMX biotopes, however (Dyer & Worsfold, 2001a). There was also considerable overlap with other mud biotopes. Aphelochaeta marioni and Tubificoides spp. in variable salinity infralittoral mud [SS.SMx.SMxVS.AphPol] (Connor et al., 2004) In sheltered muddy mixed sediments in estuaries or marine inlets with variable or reduced/low salinity communities characterised by Aphelochaeta marioni and Polydora ciliata may be present. Other important taxa may include the polychaetes Nephtys hombergii, Caulleriella zetlandica and Melinna palmata, tubificid oligochaetes and bivalves such as Abra nitida. Conspicuous epifauna may include members of the bivalve family Cardiidae (cockles) and the slipper limpet Crepidula fornicata. This biotope is often found in polyhaline waters. Worsfold (2002) assigned stones supporting the epifauna described for CreMed but without Crepidula fornicata to AphPol. Solitary ascidians were common, mainly Dendrodoa

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grossularia, Styela clava and Ascidiella spp., but the infauna was generally similar to that of AphTubi and Polydora spp. were only occasional. There were many such areas, in both estuaries, but mainly the Stour. Much of the centre of the Stour is colonised by sparse ross on mixed sediment with other epifauna and was tentatively assigned to AphPol (Worsfold & Dyer, 2004), but was transitional with the adjacent rich stable mud biotope NhomTubi. Understandably, each biotope has a different degree of sensitivity and recoverability, owing to the difference in species composition of communities and the sensitivities and recoverabilities of these species. ‘Sensitivity’ is the intolerance of a habitat, community or species (i.e. the components of a biotope) to damage, or death, from an external factor. Sensitivity must be assessed relative to change in a specific factor. In assessing sensitivity, precedence is given to using direct evidence of the effects of changes in environmental factors on a biotope. However, the magnitude of a ‘factor’ may vary widely from one event to another. It is therefore necessary to identify ‘benchmarks’ that define the degree of change in a factor. As far as possible, the benchmarks are set at a level of change likely to occur. ‘Recoverability’ is the ability of a habitat, community or species (i.e. the components of a biotope) to return to a state close to that which existed before the activity or event caused change. Table 2 Sensitivities of sublittoral biotopes relevant to the proposed Trial of a Mussel

Several Fishery Order in the Stour Estuary (see Figure 3). Modified from Connor et al. (2004) and Rayment (2008).

Factor Intolerance Recoverability Sensitivity Species richness

Evidence / Confidence

SS.SMx.SMxVS.CreMed Substratum loss High High Moderate Major decline High Smothering Low Very high Very low Minor decline Low Suspended sediment (up) Low Very high Very low No change Moderate Turbidity (up) Low Very high Very low No change Low Noise Tolerant Not relevant Not sensitive No change Low Visual presence Low Immediate Not sensitive No change High Abrasion & phys disturbance Intermediate High Low Minor decline Low Displacement Intermediate High Low Minor decline High Nutrient levels (up) Intermediate High Low Minor decline Very low Oxygenation (down) Intermediate High Low Minor decline Very low Introduction of non-natives Tolerant Not relevant Not sensitive No change High Extraction of other species Not relevant Not relevant Not relevant Not relevant Not relevant

SS.SMu.SMuVS.AphTubi Substratum loss High High Moderate Major decline High Smothering Intermediate Very high Low No change High Suspended sediment (up) Tolerant Not relevant Not sensitive No change High Turbidity (up) Low Very high Very low No change Moderate Noise Tolerant Not relevant Not sensitive No change High Visual presence Low Very high Very low No change Moderate Abrasion & phys disturbance Intermediate Very high Low Decline Low Displacement High Moderate Moderate Decline Low Nutrient levels (up) Low Immediate Not sensitive No change Very low

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Factor Intolerance Recoverability Sensitivity Species richness

Evidence / Confidence

Oxygenationb (down) Intermediate High Low Minor decline Moderate Introduction of non-natives High High Moderate Minor decline Moderate Extraction of other species Not relevant Not relevant Not relevant Not relevant Not relevant

SS.SMx.SMxVS.AphPol Substratum loss High High Moderate Major decline Moderate Smothering Intermediate High Low Minor decline Low Suspended sediment (up) Low Very high Very low No change Low Turbidity (up) Low Very high Very low No change Low Noise Tolerant Not relevant Not sensitive No change High Visual presence Tolerant Not relevant Not sensitive No change Low Abrasion & phys disturbance Intermediate High Low Decline Low Displacement High High Moderate Major decline Low Nutrient levels (up) High High Moderate Decline Low Oxygenation (down) Low Immediate Not sensitive Minor decline Moderate Introduction of non-natives High High Moderate Minor decline Low Extraction of other species Not relevant Not relevant Not relevant Not relevant Not relevant

Table 3 Species used to indicate biotope intolerance and recoverability of sublittoral and infralittoral biotopes relevant to the proposed Trial of a Mussel Several Fishery Order in the Stour Estuary (see Figure 3). Modified from Bud & Rayment (2001), Bud & Hughes (2005), Rayment (2007), Tyler-Walters (2007 & 2008) and Budd (2008).

SPECIES Key structural

Important characterizing Important other

Relevant other

Factor Polydora ciliata

Crepidula fornicata

Aphelochaeta marioni

Mya arenaria Ascidiella scabra

Nephtys hombergii

Intolerance Substratum loss High High High High High Intermediate Smothering Tolerant Low Low Intermediate Low Tolerant Suspended sediments (up)

Tolerant Low Tolerant Intermediate Low Tolerant

Turbidity (up) Tolerant Low Low Low Tolerant Not relevant Noise Tolerant Tolerant Tolerant Tolerant Tolerant Tolerant Visual presence Low Tolerant Low Tolerant Tolerant Tolerant Abrasion & phys disturbance

Intermediate Intermediate Intermediate Intermediate High Intermediate

Displacement Low Intermediate Tolerant Intermediate High Tolerant Nutrient levels (up)

Low Insufficient information

Intermediate Intermediate Insufficient information

Low

Oxygenation (down)

Low Intermediate Low Low Low Tolerant

Introduction of non-natives

Insufficient information

Tolerant Insufficient information

Intermediate Tolerant Tolerant

Extraction of other species

Not relevant Tolerant Intermediate High Not relevant High

Recoverability Substratum loss High High High High Very high Very high Smothering Not relevant Very high Immediate High Immediate Not relevant Suspended Not relevant Very high Not relevant High Immediate Not relevant

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SPECIES Key structural

Important characterizing Important other

Relevant other

Factor Polydora ciliata

Crepidula fornicata

Aphelochaeta marioni

Mya arenaria Ascidiella scabra

Nephtys hombergii

sediments (up) Turbidity (up) Not relevant Very high Very high Immediate Not relevant Not relevant Noise Not relevant Not relevant Not relevant Not relevant Not relevant Not relevant Visual presence Not relevant Not relevant Immediate Not relevant Not relevant Not relevant Abrasion & phys disturbance

High High High High Very high Very high

Displacement High High Not relevant High Very high Immediate Nutrient levels (up)

High Not relevant High High Not relevant Very high

Oxygenation (down)

High High Very high Immediate Immediate Not relevant

Introduction of non-natives


Not relevant Not relevant High Not relevant Not relevant

Extraction of other species

Not relevant Not relevant High High Not relevant Very high

Table 4 Information extracted from the Seabed Indicator Species Database to support

implementation of the EU Habitats and Water Framework Directives (Hiscock et al., 2005).

Factor Hediste diversicolor

Macoma balthica

Arenicola marina

Cerastoderma edule

Nephtys hombergii

Streblospio shrubsoli

Smothering

Intolerant

Physical disturbance

Intolerant Intolerant Intolerant – Highly intolerant

Intolerant

Nutrients

Favoured Favoured Favoured Favoured

De-oxygenation Tolerant Highly intolerant

Tolerant

‘Favoured’ = identified as ‘likely to be present in higher abundance than expected’ ‘Tolerant’ = identified as ‘neutral’ ‘Intolerant’ = identified as ‘likely to be absent as a result of the factor’ ‘Highly intolerant’ = identified as ‘likely to be absent as a result of the factor’ In summary, there are no Nationally Rare or Scarce species or species listed under any importance categories. Furthermore, all relevant biotopes and species show in general good recoveries from activities associated with the mussel cultivation. 3.3 ORNITHOLOGY The outer Stour is becoming sandier and substrates become progressively muddier further upstream. There are seven shallow bays along the estuary and sharply rising land or cliffs, covered with ancient coastal woodland and agricultural land, leaving little room for saltmarsh development, border much of its length. Much of the intertidal substrate of the Orwell is

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fairly muddy. In mitigation for the latest port development, part of the north and south shores of the lower reaches of the estuary have had soft silts placed behind stiff clay bunds within the intertidal areas, changing the substrate again. Long stretches of farmland and wet meadow are situated along the mid-estuary, the latter providing roost sites for waterbirds. Nature conservation in the area includes the Stour & Orwell Estuaries Ramsar site and SPA, with management by RSPB, Woodland Trust, Essex Wildlife Trust and Suffolk Wildlife Trust. Sailing, shooting and bait digging occurs, though the major concern is through a marked increase in recreation activities, especially with dogs on important feeding and roosting areas. Additionally, the Stour has lost more than half of its saltmarsh over the last 35 years. This is especially noticeable on the Orwell because of its narrow mudflats. The estuaries are here considered together as one functional unit to reflect the extent of the SPA designation. The high productivity of intertidal mudflats also provides a valuable feeding resource for birds. Direct observation and analysis of the diet of wading birds indicated that Hediste diversicolor constitutes the main prey of about 15 waders and is the dominant prey for the Avocet Recurvirostra avosetta, the Grey plover Pluvialis squatarola, the Curlew sandpiper Calidris ferruginea, the Bar-tailed godwit Limosa lapponica and the Curlew Numenius arquata (see Goss-Custard et al., 1977a&b, and review by Zwarts & Esselink, 1989). Bivalves, including Cerastoderma edule and Mya arenaria, are also predated by several bird species, mainly waders, ducks and gulls (Meire, 1993). The main predator of bivalves in estuaries is probably the oystercatcher, Haemotopus ostralegus. Drinnan (1957) (cited in Meire, 1993) estimated that oystercatchers remove 22 % of the cockle population in Morecambe Bay, UK. The intertidal sediment flats also exploited by bait diggers (Anon, 1999), the principal target species being the polychaetes, Hediste diversicolor and Arenicola marina. The ornithological status of the Stour-Orwell Estuaries (Ravenswood et al., 2007) is currently not favourable. In the five winter period of 2000/01 to 2004/05, the SPA supported an average peak count of 72,993 birds at high tide (53,012 on the Stour and 19,981 on the Orwell; cf. Table 5) and twelve wader or wildfowl species were present on one or the other estuary in nationally or internationally important populations (>1 % of GB and East Atlantic populations respectively) (Banks et al., 2006). The status of both estuaries has decreased in recent years since large numbers of birds occurred during a series of cold winters in the 1980s (Wright, 2001). Based on the count data over the past 10+ years, the Stour has lost international status for Dunlin and Golden plover and its national status for Wigeon, Ringed plover, Lapwing and Curlew, and the Orwell has lost national status for Shelduck, Grey plover and Dunlin since 1999 (SWT, 2007). One species has gained national status in the same period, i.e. turnstone on the Stour. Furthermore, most of the 17 bird species listed in the SPA citation have British Trust for Ornithology (BTO) Alert Status, i.e. their numbers have fallen significantly in the estuaries over 5, 10 and 25 year period (Armitage & Rehfisch, 2002). Based on the most recent, published WeBS data from winter of 2009/10 (Holt et al., 2011) of more than 200 sites across the UK holding 10,000 or more waterbirds, the Stour Estuary returned the second largest decrease in five-year average bird numbers (i.e. -13 %; Table 5).

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Table 5

Total number of waterbirds on the Stour and Orwell Estuaries 2005/06 to 2009/10 (includes data from all available sources) and species occurring in internationally important numbers.

Stour Estuary

2005/06 2006/07 2007/08 2008/09 2009/10 Average

Species occurring in internationally important numbers

38,094 35,069 40,305 49,937 55,449 43,771 Black-tailed godwit, Grey plover, Knot and Mute swan

Orwell Estuary

2005/06 2006/07 2007/08 2008/09 2009/10 Average

Species occurring in internationally important numbers

26,996 23,995 20,510 23,934 21,009 23,289 Black-tailed godwit

Apart from the possibility that there are long-term fluctuations in the bird populations of the estuaries, there are many potential causes of the downward trend in numbers (Ravenswood et al., 2007):

(1) The prolonged effects of losses of habitat to development or erosion on the estuaries, i.e. the Orwell has lost large areas of mudflats at its mouth to port development and the saltmarsh area of both estuaries has been reduced by about half in recent years (Cooper et al., 2000). Loss of habitat ultimately affects the size of the population of wintering waders (Goss-Custard et al., 1995).

(2) Dredging activity at Harwich may have had an impact on the hydrodynamics of the

estuaries, despite a programme of mitigation works, and may have affected the deposition of sediment (PDE, 1998). The composition of both invertebrate and bird faunas reflect the sediment composition of mudflats (Yates et al., 1993).

(3) Global warming may be affecting the patterns of migration of wintering birds, but the

effects of this on local populations are yet to be established. For instance, birds may not be travelling as far south to winter owing to warmer temperatures (Austin & Rehfisch, 2005).

(4) Recent changes in water quality, particularly on the Orwell, as improvements reduce

the quantity of food available to birds (Burton et al., 2002a).

(5) Disturbance from recreational activities, as continual disturbance reduces numbers of birds and the habitat quality of estuaries (Burton et al., 2002b).

The level of recreation on the estuaries is thought to be relatively high (boating, bait digging, shooting, walking, etc.) as is the commercial activity associated with the ports of Felixstowe, Harwich and Ipswich, but there is little information available about the disturbance that this may cause to wintering birds. The relatively low numbers of bird roosting beside the Orwell at high tide compared with those feeding at low tide suggest that the effects of disturbance, at least at high tide, may be severe (Armitage et al., 2003), as birds prefer to roost close to their feeding grounds (Symons & Langslow, 1986; Rehfisch et al., 2003).

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A study commissioned by the RSPB, Suffolk Wildlife Trust and the Suffolk Coast and Heaths AONB Unit has identified bait diggers, dogs off leads at high tide and running on to mudflats at low tide, fast moving boats and gun shots as the main causes of bird disturbance (Ipswich Borough Council, 2010). Distribution maps of key bird species in the Stour and Orwell Estuaries, produced from the Wetland Bird Survey (WeBS) 2009/101, are presented in Figures 5 to 7. WeBS Low Tide Count data are presented as dot density maps, with subdivision of count sections into basic habitat elements. The following colour conventions apply to density maps: yellow = inter-tidal habitat (e.g. mudflat, sandflat); pale blue = water and pale green = non-tidal habitat (e.g. saltmarsh, reedbed). The maps display the average number of birds in each count section as dots spread randomly across habitat components of count sections, thus providing an indication of both numbers and density.2 It is important to note that individual dots do not represent the precise position of individual birds; dots have been assigned to habitat components proportionally and are then randomly placed within those areas. No information about the distribution of birds at a finer scale than the count sector level should be inferred from the dot density maps. For all maps, one dot is equivalent to one bird. The size of individual dots has no relevance other than for clarity. A table listing the habits and habitat requirements of all nationally and internationally important waders and wildfowl present in the Stour and Orwell Estuaries can be found in Appendix I. It is noteworthy in Figures 5 to 7 that all waders and wildfowl utilise the intertidal areas very intensively. Understandably, only duck and geese species (and probably Mute swans) also venture onto open water. This is of relevance, because Plots 1 to 4 are adjacent to bird feeding areas and can be worked also at low water. However, the mussel dredgers are very slow moving and quiet when working the beds (2 to 3 knots), resulting in minimal disturbance, if any. Plot 5, on the other hand, is the most shallow mussel lay and can only be fished at high water when the surrounding sandbanks are covered with water and the birds will have moved further up the shore. Furthermore, the mussel lays will not be worked all at the same time, with working effort being spread over the whole season. 1 Undertaken by volunteers of the British Trust for Ornithology (BTO) 2 http://www.bto.org/volunteer-surveys/webs/latest-results/stour-and-orwell-estuaries#maps [accessed 18 March 2012]

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Avocet Bar-tailed godwit

Black-tailed godwit Dark-bellied Brent goose

Curlew Dunlin

Golden plover Grey plover Figure 5 Stour and Orwell Estuaries Low Tide Distribution Maps for Key Species 2009/10.3

3 http://www.bto.org/volunteer-surveys/webs/latest-results/stour-and-orwell-estuaries-distribution-maps-key-species-200910 [accessed 18 March 2012]

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Knot Lapwing

Mallard Oystercatcher

Pintail Redshank

Ringed plover Shelduck Figure 6 Stour and Orwell Estuaries Low Tide Distribution Maps for Key Species 2009/10.4


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Teal Turnstone

Wigeon Figure 7 Stour and Orwell Estuaries Low Tide Distribution Maps for Key Species 2009/10.5 3.4 FISH AND SHELLFISH Brown shrimp Crangon crangon, Pink shrimp Pandalus montagui, Dover sole Solea solea, Herring Clupea harengus, Bass Dicentrarchus labrax, Cod Gadus morhua and Whiting Merlangius merlangus have been identified as the most important species present in the Stour and Orwell Estuaries (Worsfold, 2002). In the Orwell Estuary, Colclough (2010) found Sand smelt Atherina presbyter and bass nurseries along the estuary, with many nursery sites apparently present for most of the year. Data from 6 sites that have been fished in the Orwell Estuary since 2004 suggest that the whole estuary is a very important bass nursery ground, with the number of bass increasing significantly from none identified in a fish monitoring survey conducted in 1999 (Dyer, 2005) to many found in a survey conducted between December 2003 to 2004 (Ashelby, 2005). In addition, the Environment Agency considers the almost permanent presence of juvenile bass here to be unprecedented amongst British estuaries (EA, unpublished data; Natural England, 2011). Flounder Platichthys flesus nurseries are also present at Trimley and off Colimer Point, and appear to be concentrated towards the head of the Stour Estuary at Doverhouse and Mistley (Colclough, 2010). Furthermore, the European eel Anquilla anquilla has been noted as one of the most important taxa present in the Stour and Orwell Estuaries (Worsfold, 2002).


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4 DESCRIPTION OF THE PROPOSED MUSSEL CULTIVATION OPERATIONS 4.1 ACCESS Access to and from the mussel lays will be by slow-moving boat(s) only, at a maximum speed of 8 knots. Boat speed when working the mussel lays will be a maximum of 2 to 3 knots only. The mussel lays will be worked predominantly during daylight hours; work on the lays at night will be rare. As all five mussel lays are subtidal, they can be worked at any stage of the tide, except for Plot 5 which will require high water conditions for access. 4.2 SETTING UP The total number of hours anticipated to be spent working the mussel lays is shown in Table 6. These are averaged guesstimates, based on experiences from working mussel lays in The Netherlands. Before relaying seed mussel for the first time, the plots will be cleaned with a Dutch mussel dredge (for details, see Section 4.6 below), foremost to remove predators, in particular Slipper limpet which is very abundant on Plot 5 and will therefore require an estimated effort of ca. 10 hours per hectare. It is estimated that the other mussel lays will require an effort of less than 2 hours per hectare. Table 6 Estimated times of effort for the various activities on the five mussel lays.

Estimated effort of various activities on the mussel lays [in hours] Plot Cleaning before seed relaying

Seed relaying Harvesting Cleaning after harvesting

Predator control

1 <68 hrs 34 hrs 136-204 hrs 136-204 hrs TBD 2 <36 hrs 18 hrs 72-108 hrs 72-108 hrs TBD 3 <24 hrs 12 hrs 48-72 hours 48-72 hours TBD 4 <10 hrs 10 hrs 40-60 hrs 40-60 hrs TBD 5 100 hrs 10 hrs 40-60 hrs 40-60 hrs TBD TOTAL <238 hrs 84 hrs 336-504 hrs 336-504 hrs TBD OVERALL TOTAL <994-1,330 hrs (+ predator control) 4.3 SOURCING OF SEED MUSSEL Seed mussel will be sourced from local, ephemeral beds that are abundant along the coast of East Anglia, such as at Cromer, Great Yarmouth and Ramsgate. Whilst there are also significant seed mussel resources in The Wash and around Carmarthen Bay (South Wales), these will not be targeted, chiefly because of the annually recurring atypical cockle mortalities there and the very high risk of transferring pathogens from these areas to the Stour Estuary. Local seed mussel successfully recruits annually, grows over the summer but is then either heavily predated upon by Starfish Asterias rubens and other predators or removed and dispersed by winter storms into deeper water. Seed harvest (and relaying) is anticipated to be carried out between September and April, but these dates may vary and even extend to all year round, given environmental and seed mussel resource conditions.

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The vessels to be used are equipped with ground discriminating sonar equipment to identify areas suitable for fishing before deploying the dredges. A ‘MUS 2 Licence’ will be applied for to the Marine Management Organisation (MMO) to collect mussel seed. Whenever possible, seed mussel will be sourced from outside of European Marine Sites (SACs and SPAs), unless a Habitats Regulations Assessment under Regulation 61 of The Conservation of Habitats and Species Regulations 2010 (as amended) has been undertaken for that specific reason. Notwithstanding the aforesaid and as mentioned before, no seed mussel will be sourced from The Wash. Only a maximum of 2,100 tonnes of seed mussel will be required annually for this Trial MSFO, which constitutes a very small proportion of the estimated biomass of ephemeral seed mussel along the coast of East Anglia. The applicant is currently also considering spat collection from ropes deployed in sheltered, near-shore locations. Natural England will be consulted on this potential operation and consent to be applied for from the DEFRA. The DEFRA would subsequently be notified of any changes to the operation of the TMSFO. 4.4 RELAYING OF SEED MUSSEL Seed relaying will be carried out immediately subsequent to seed mussel gathering. Targeted, precision relaying of seed mussel by boat will be achieved by using a GPS to areas that will also have been temporarily marked with buoys. The cleaned area will receive seed mussel at an initial low density not exceeding 5 kg m-2 (50 tonnes ha-1). This should ensure that carrying capacity of the Estuary will not be exceeded. Seed relaying itself will take about 1 hour per hectare. Strict biosecurity measures will be adhered to (see Section 5 ‘Biosecurity’ below). 4.5 PREDATORS AND THEIR CONTROL Oystercatcher Haematopus ostralegus, Knot Calidris canutus, Starfish Asterias rubens, Brown crab Cancer pagurus and Velvet crab Necora puber are only a few of the potential predators of mussels. Only crabs and starfish are of relevance to this application. Crabs will be caught by way of baited pots (subject to a separate fishing licence application) and removed from the fishery as an additional commercial target species. It is envisaged that starfish mops will be employed at times of high starfish infestation of the beds. This gear, consisting of a single beam equipped with multiple 1.5 m lengths of cotton mops, is lightweight and when towed from a vessel over the beds entangles starfish which are then recovered, removed and disposed of alive outside any marine protected area. 4.6 HARVESTING Harvesting will be dictated by growth and sizes but it is envisaged that this will occur 12 to 18 months after relaying.

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The mussels will be harvested by mussel dredgers with one or two dredges on each vessel. The frame of the 2-metre steel dredge will have a weight of approximately 200 kg, with a 2 to 3 meter long bag attached to the frame. The bottom part of the bag is normally made up of a chain link matrix, with the upper part of the bag being made of nylon mesh. Two types of steel frames will be used: the Dutch style mussel dredge and the Box dredge. Depending on the local conditions on a lay, for instance quantity of mussels, type of substrate (whether muddy or sandy), etc., it will decided which type of dredge to deploy at that stage. The mussel dredges are equipped with a bar to prevent bottom penetration. This design was developed to only skim the sediment surface and not penetrate it whilst removing the mussels. By-catch will be monitored. Harvesting of half- or fully-grown mussels will take about 4 to 6 hours per hectare. The same amount of time per hectare is estimated to be required for cleaning the plots after harvesting. Subject to the classification of the mussel production area under the Shellfish Hygiene Directive, the mussels may have to undergo depuration. 5 BIOSECURITY 5.1 BACKGROUND It must be appreciated that it is very difficult to apply meaningful biosecurity measures in estuarine and open marine environments. The greatest risk of introducing disease into a shellfish area comes with movements of live shellfish. In addition to the risk of introducing disease through shellfish movements, there are other routes by which disease can be introduced to a shellfish area and spread to others, for instance transfer by soiled vehicles, boats, equipment and footwear. In this instance, to reduce that risk, areas for biosecurity consideration should include:

• transport of personnel and catch by boat(s) and RIB(s) to and from the site; • use of fishing implements and other associated equipment, incl. mussel bags; and • external clothing and footwear

The new Aquatic Animal Health (England and Wales) Regulations 20096 transposes Council Directive 2006/88/EC into UK Law. The Regulations recognise the importance of effective biosecurity measures in restricting disease spread. It requires Aquaculture Production Business (APB) operators to implement a biosecurity measures plan as a condition of their authorisation. The 2009 Regulations require the authorisation of all aquaculture businesses - fish and shellfish farms. This Statutory Instrument has replaced previous legislation which required fish and shellfish farms to be registered. 6 SI 2009 No. 463 http://www.legislation.gov.uk/uksi/2009/463/regulation/3/made

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The business owner or operator is required to meet the minimum record keeping and biosecurity standards. The overall purpose of authorisation is to prevent the introduction and spread of infectious disease within the UK. All new fish and shellfish farms are required to apply for authorisation before any development takes place. Applications for authorisation of new APBs need to be submitted to the Fish Health Inspectorate (FHI) at the Cefas Laboratory, Weymouth. The FHI issues guidance on the specific requirements to be addressed before authorisation is granted. Notwithstanding the aforesaid, the 2009 Regulations do not apply to any wild aquatic animal harvested or caught for direct entry into the food chain other than one which is to be treated as an aquaculture animal under regulation 18(3)7. Biosecurity for wild shellfisheries, such as gathering of cockles and mussels above the minimum legal size, falls therefore outwith any practical and appropriate legislative controls. The following needs to be looked at and appreciated against the backdrop of annually recurring cockle die-offs in The Wash and in South Wales. The introduction of appropriate biosecurity measures has become necessary following the recent discovery of an unprecedented number of introduced parasites in cockles in these areas, including two non-native species of Minchinia that have been implicated in the atypical cockle mortalities (Elliott et al., 2012; Longshaw & Otto, 2012). Very little is known about the life cycle of Minchinia spp., their intermediary hosts, carriers, modes and vectors of disease transmission. It is not inconceivable that the Blue mussel Mytilus edulis could be a carrier, bearing in mind that Minchina spp. have jumped species before. Consequently the same biosecurity measures recommended for cockle fisheries must also apply to wild mussel fisheries and APBs, until such time that laboratory analysis has proven the absence of Minchinia spp. in mussels beyond reasonable scientific doubt. Furthermore, the pathogens found in cockles of The Wash and in South Wales are not “listed diseases” and are therefore also not notifiable under current legislation. Information on shellfish diseases information can be found in a variety of sources:

o Textbooks on shellfish cultivation / diseases o Periodicals (Shellfish News, Fish Farming International, etc.) o Disease recognition leaflets o Further information is available on the Cefas FHI website @ www.efishbusiness.co.uk

Biosecurity information can be found on the GB Non-Native Species Secretariat website @ https://secure.fera.defra.gov.uk/nonnativespecies/index.cfm?sectionid=58

7 18(3) Where any wild aquatic animal, which is susceptible to a listed disease or is a vector for that disease, is introduced into England or Wales for further processing before human consumption, the animal is, for the purpose of regulation 17(1), to be treated as though it is an aquaculture animal introduced for further processing before human consumption. 17(1) It is an offence to introduce any aquaculture animal or any aquaculture animal product into England or Wales where the animal or product is required to be accompanied by an animal health certificate under Article 5 of Decision 2004/453/EC or Chapter III or IV of Regulation (EC) No.1251/2008 unless it is accompanied by such a certificate completed in accordance with the relevant model specified in that Article or Chapter.

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5.2 PROPOSED BIOSECURITY MEASURES

(a) The 2008 Code of Good Practice for Mussel Seed Movements by the Bangor Mussel Producers Association (BMPA, 2008) will be strictly adhered to.

Furthermore –

(b) Access to the TMSFO will be allowed by boat(s) and RIB(s) only. (c) Boat(s), RIB(s), dredging gear, declumping and grading equipment, etc. used in

particular in The Wash or South Wales should be power-washed to remove all sediment and organic matter prior to their use in the Stour Estuary. Particular emphasis should be placed on any areas that have come into contact with shellfish or intertidal sediments, for instance via loaded cockle and mussel bags, footwear or external clothing. In general, returning to the Stour Estuary from outside areas should require power-washing prior to entering the estuary to prevent introduction of new / additional pathogens and invasive non-native species.

(d) All participants in the mussel cultivation operations should thoroughly wash all their

external clothing and clean footwear and all equipment / implements used in any shellfish operations they are involved in and allow time to dry. This includes cockle, mussel or sample bags to be reused elsewhere. All sediment and organic matter should be removed.

6 POTENTIAL ENVIRONMENTAL EFFECTS A brief summary of the known and potential impacts of seabed mussel cultivation, as highlighted in the report is provided in Table 7 below. 6.1 SEED MUSSEL COLLECTION

Seed mussel often forms dense aggregations in discrete areas of the seabed, which are

of commercial interest to the mussel cultivation industry.

Physical disturbance due to dredging will be confined to relatively small areas of the seabed on which these dense aggregations occur. Light dredges are towed through the seed mussel beds enabling seed to be skimmed from the surface, leaving the underlying substratum relatively unaffected.

Seed mussel beds not harvested may be lost during winter storms, although the temporal variability in occurrence and biomass of many of these ‘ephemeral’ beds is not entirely understood.

The ecological role of wild seed mussel beds in the wider ecological community has not been studied systematically.

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6.2 MUSSEL CULTIVATION AND HUSBANDRY TECHNIQUES (a) Change in benthic community structure

Through smothering of the underlying habitat, provision of a complex habitat, input of organically rich material and larval removal through filter feeding, cultivated mussel beds can alter the infaunal benthic community of the adjacent and interstitial sediments onto which they are re-laid.

Effects of commercial seabed mussel cultivation have shown that the presence of mussels resulted in a significant change in the composition of species of the infaunal community within the cultivated area, with a reduction in the total number of individuals and numbers of species compared with areas without mussels.

Effects of intertidal mussel beds on infaunal communities has been demonstrated to reduce with increasing distance from the mussel bed. Localised effects can occur at a scale of 0-10 m, but effects at larger scales (10-100 m) are not detectable. No equivalent information is available for subtidal mussel lays yet.

(b) Change in phytoplankton community structure

Filter feeding by mussels is a major mechanism for the removal of suspended material such as phytoplankton, detritus and inorganic seston from the water column to the benthos.

Mussel filter feeding can affect the plankton community structure, due to non-selective feeding skewing the community towards smaller faster growing species, causing a shift in the population to higher proportions of diatoms (high growth-rate species) and declines in relatively slow growing dinoflagellates.

Water does not appear to flush through the Stour Estuary on each tidal cycle and may have a residence time of possibly even several days, such that mussels have the ability to significantly alter the structure of phytoplankton populations and reduce the amount of suspended organic material available to other filter feeders in the Stour Estuary, some of which are of conservation importance.

(c) Effects of faecal and pseudofaecal waste

Mussels have the ability to produce large amounts of fine sediments (faeces and pseudofaeces).

Biodeposition of fine sediments resulting in a build up of ‘mussel med’ beneath the cultivated mussels varies considerably depending on variations in local seston concentrations, densities of the bivalves and local hydrographic factors.

Organic content of mussel mud is significantly higher than surrounding sediments, leading to increases in oxygen consumption, anoxia and increased sulphate reduction. May also represent a significant food resource for various infaunal species.

Dredging of mussel beds, during harvesting and husbandry, as well as routine dredging mud banks, following harvest produces plumes of sediment and releases particles, nutrients and oxygen-consuming substances from the sediment into the water column.

Sediment may remain in suspension up to 60 minutes following dredging activity, such that settlement of mussel mud may occur in locations other than the main area of

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cultivation. This could potentially smother species or habitats sensitive to high sediment loads.

(d) Changes in nutrient flux

Mussels have an important ecological role in the biogeochemical cycling processes that occur at the seabed and the interface with the water column above, through their own metabolism and through bacterial decomposition of organic material within the mussel bed, such that nutrient fluxes on mussels beds tend to be higher than on sediment without bivalve beds.

Ecological consequences of mussel cultivation for these processes are as yet unknown and will need to be linked to a consideration of the effects of mussel cultivation on the carrying capacity of the Stour Estuary.

(e) Effect of increased food supply for predators

Most important predators of mussels are predatory gastropods (e.g. Dogwhelk Nucella lapillus, Starfish (e.g. Asterias rubens), crabs (e.g. Cancer pagarus and Carcinus maenas) and shore birds (e.g. oystercatcher Haematopus ostralegus).

The major predatory species on the cultivated mussels in the Stour Estuary and surrounding areas will be the starfish Asterias rubens and the Shore crab Carcinus maenas, and it is possible that the presence of cultivated mussel beds will have a positive effect on populations of these species in the Stour Estuary area, through the provision of an extra food resource.

The mussel lays will attract Slipper limpets Crepidula fornicata from a wider area, but will then be removed regularly, thereby benefiting the wider ecosystem.

It is important to note that whilst many of the above environmental impacts of seabed mussel cultivation are clearly understood in other geographical locations, the exact potential impacts on the marine wildlife habitats and species in the Stour Estuary are as yet difficult to predict. Consequently a precautionary approach has been adopted by this ES. It is acknowledged that the proposed mussel cultivation in the Stour Estuary is potentially of high economic value to the region and the proposed management and mitigation measures contained within this ES are designed to ensure that the mussel fishery is managed in such a way as to be compatible with the nature conservation interests of the area. 6.3 PROPOSED MANAGEMENT AND MITIGATION MEASURES A review of potential environmental effects has been undertaken and a wide range of detailed management and mitigation measures has been identified that will address and reduce them.

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Table 7 Potential effects and proposed management and mitigation measures

Issue Nature of potential Effects Mitigation of adverse Effects

Will Mitigation remove the Risk of adverse Effects?

Access to the areas of the TMSFO by boats and RIBs

(a) Damage to sensitive intertidal and subtidal habitats when moored during low tide;

(b) disturbance and displacement of seabirds;

(c) introduction of non-native species (fauna and flora) and pathogens; and

(d) risk of pollution.

(a) Identify less sensitive subtidal areas only and mark temporarily with a buoy before mooring;

(b) a maximum of 2 plots only to be worked simultaneously at any one time;

(c) a 3 knots maximum boat speed limit when working the mussel lays, with a 8 knots maximum speed limit throughout the remainder of the Stour Estuary;

(d) implementation of strict biosecurity measures; and

(e) keep boats and RIBs well maintained and serviced.

Yes

Sourcing of seed mussel

(a) Sources of seed mussel the result of collection / fisheries within EMSs that have not undergone HRAs; and

(b) introduction of non-native species (fauna and flora) and pathogens.

(a) Sourcing of intertidal seed mussel from within any marine SAC or SPA only if it was subject to a HRA;

(b) no sourcing of seed mussel from The Wash or from South Wales; and

(c) implementation of strict biosecurity measures.

Yes

Relaying of seed mussel

(a) Deposition of seed mussel on adjacent intertidal mudflats and sandflats and within tidal creeks;

(b) possible long-term changes to hydrodynamics and associated sediment processes;

(c) increase in sedimentation (mussel faeces & pseudo-faeces, increased natural deposition due to reduced bed flow);

(a) Total area of seed mussel relaying not to exceed 84 ha;

(b) seed relaying on the proposed five subtidal plots only;

(c) initial density of seed mussel on relaying not to exceed 5 kg m-1;

Yes

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(d) deposition of mussel shell debris and import of other material (e.g. coarse sediments brought in with seed mussel);

(f) infilling of tidal creeks and infilling / smothering of existing depressions (‘mud pools’); and

(j) introduction of non-native species (fauna and flora) and pathogens.

(d) no deposition of seed mussel on adjacent intertidal mudflats and sandflats and within tidal creeks;

(e) targeted precision relaying of seed mussel by boats only;

(f) a maximum of 2 plots only to be worked simultaneously at any one time; and

(g) implementation of strict biosecurity measures.

Spawning and spat settlement

(a) Mussels may out-compete indigenous epifauna;

(b) import of mussel will increase the reproductive potential of the species within the estuary, possibly resulting in increased recruitment and impact on other areas of the estuary; and

(c) potential increase in area occupied by mussels at the expense of other beds of bird prey species.




(d) surveillance with drop-down video of adjacent areas of the TMSFO; and

(e) continued consultation with Natural England and shellfish researchers at Bangor and Swansea Universities.

Yes

Carrying capacity

(a) Exceeding the natural ecological carrying capacity of the site;

(b) increased predation of larvae of other species;

(c) increased production and release of ammonia; and

(d) attraction to and concentration of predators from a wide area at the site (potential impact on ecosystem




Yes

33



of wider area). (d) surveillance with drop-down video of adjacent areas of the TMSFO;

(e) limited control of predators only; and

(f) continued consultation with Natural England and shellfish researchers at Bangor and Swansea Universities.

Nutrient and contaminant enrichment

(a) Potential changes to chemistry of parts of the mussel bed and adjacent soft sediments (anoxic, nutrient and carbon rich) due to organic input from faeces and pseudo-faeces;

(b) further increase in nutrient loading, as nutrients are being released from faeces, and retained within the system rather than being flushed out with the tide.

(c) increase in nutrient rich suspended sediment plumes;

(d) increased production and release of ammonia; and

(e) contaminants tend to be adsorbed onto fine sediments / flocs and it is these that the mussels will tend to deposit / concentrate at this location; consequently contaminant levels are likely to increase, but to what level depends on existing contamination in the water column in the estuary.




(d) no deposition of seed mussel on adjacent intertidal mudflats and sandflats and within tidal creeks;


(f) a maximum of 2 plots only to be worked simultaneously at any one time;

(g) harvesting with bladed dredges only;

(h) surveillance with drop-down video of adjacent areas of the TMSFO; and

(i) continued consultation with Natural England and shellfish researchers at Bangor and Swansea Universities.

Yes

34



Harvesting (a) Damage to sensitive intertidal and subtidal habitats;

(b) removal of prey resource for mussel-eating waders; and

(c) disturbance and displacement of seabirds.

(a) Harvesting from the five proposed subtidal mussel lays only;

(b) a maximum of 2 plots only to be worked simultaneously at any one time;

(c) a 3 knots maximum boat speed limit when working the mussel lays, with a 8 knots maximum speed limit throughout the remainder of the Stour Estuary;

(d) harvesting with bladed dredges only;

(e) total tonnage of harvested mussel from areas of TMSFO not to exceed 2,100 tonnes annum-1;

(f) monitoring of by-catch;

(g) surveillance with drop-down video of adjacent areas of the TMSFO; and

(h) implementation of strict biosecurity measures.

Yes

Predators and their control

(a) Attraction to and concentration of predators from a wide area at the site, such as Starfish (Asterias rubens), Brown crab (Cancer pagurus) and Velvet crab (Necora puber);

(b) removal of predators concentrated on the mussel bed (potential impact on ecosystem of wider area); and

(c) disturbance and displacement of seabirds.

(a) Monitoring of predator populations;

(b) limited control of predators only;

(d) surveillance with drop-down video of adjacent areas of the TMSFO; and

(e) a 3 knots maximum boat speed limit when working the mussel lays, with a 8 knots maximum speed limit throughout the

Yes

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remainder of the Stour Estuary.

7 PROTECTED SITES, HABITATS AND SPECIES 7.1 INTRODUCTION The area of the proposed Trial MSFO lies wholly within the Stour and Orwell Special Protection Area (SPA) and Ramsar site (Wetland of International Importance under the Ramsar Convention). As a matter of Government policy, Ramsar sites should be treated in the same way as SPAs and SACs. Both sites are therefore afforded protection under the 1992 EC Habitats Directive8. The Stour Site of Special Scientific interest (SSSI) is part of the Stour and Orwell Estuaries Wetland of International Importance under the Ramsar Convention and the Stour and Orwell Estuaries Special Protection Area under the EEC Council Directive on the Conservation of Wild Birds (79/409/EEC). The Stour Estuary Site of Special Scientific Interest (SSSI) ‘underpins’ the SPA and Ramsar site. The SSSI is subject to the Wildlife & Countryside Act 1981 (as amended; most recently by the Countryside & Rights of Way Act 2000). The recommended Marine Conservation Zone is also being considered here, in addition to a Biodiversity Action Plan (BAP) Priority Habitat, i.e. ‘Sheltered muddy gravels’ and its associated biotopes, including a BAP priority biotope, dominated by the invasive, non-native Slipper limpet Crepidula fornicata. Potential impacts on nationally scarce brackish water species, the Starlet sea anemone Nematostella vectensis and the Tentacled lagoon worm Alkmaria romijini, are also being discussed here. The Stour Estuary is also listed as a site of national importance in A Nature Conservation Review (Ratcliffe, 1977). 7.2 STOUR AND ORWELL SPECIAL PROTECTION AREA In 1994 the Stour and Orwell Estuaries were recommended as a Special Protection Area (SPA) under the Birds Directive (79/409/EEC) because of the site’s European ornithological interest which is supported by the quality and extent of its intertidal mudflat and sandflat habitats which support nationally and internationally important populations of waders and wildfowl. For the full citation, see Appendix II.

8 Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora (OJ No L 206)

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The estuaries include extensive mudflats, low cliffs, saltmarsh and small areas of vegetated shingle on the lower reaches. The mudflats hold Enteromorpha, Zostera and Salicornia spp. The site also includes an area of low-lying grazing marsh at Shotley Marshes on the south side of the Orwell. In summer, the site supports important numbers of breeding Avocet Recurvirostra avosetta, while in winter they hold major concentrations of waterbirds, especially geese, ducks and waders. The geese also feed, and waders roost, in surrounding areas of agricultural land outside the SPA. The site has close ecological links with the Hamford Water and Mid-Essex Coast SPAs, lying to the south on the same coast. This site qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting populations of European importance of the following species listed on Annex I of the Directive: Hen Harrier Circus cyaneus (over winter only) This site also qualifies under Article 4.2 of the Directive (79/409/EEC) by supporting populations of European importance of the following migratory species: Black-tailed Godwit Limosa limosa islandica, Dunlin Calidris alpina alpina, Grey Plover Pluvialis squatarola, Pintail Anas acuta, Redshank Tringa totanus, Ringed Plover Charadrius hiaticula, Shelduck Tadorna tadorna, Turnstone Arenaria interpres. The area qualifies under Article 4.2 of the Directive (79/409/EEC) by regularly supporting at least 20,000 waterfowl. Over winter, the area regularly supports 64,768 individual waterfowl (5 year peak mean 1991/2 - 1995/6) including: Cormorant Phalacrocorax carbo, Pintail Anas acuta, Ringed Plover Charadrius hiaticula, Grey Plover Pluvialis squatarola, Dunlin Calidris alpina alpina, Black-tailed Godwit Limosa limosa islandica, Redshank Tringa totanus, Shelduck Tadorna tadorna, Great Crested Grebe Podiceps cristatus, Curlew Numenius arquata, Dark-bellied Brent Goose Branta bernicla bernicla, Wigeon Anas penelope, Goldeneye Bucephala clangula, Oystercatcher Haematopus ostralegus, Lapwing Vanellus vanellus, Knot Calidris canutus, Turnstone Arenaria interpres. The qualifying features of the Stour and Orwell SPA and Ramsar site, and the Stour SSSI have changed over time (Table 8). Bird populations do change as a reflection of national or international trends or events. However, in case of the Stour and Orwell SPA, habitat loss and other factors discussed in Sections 3.1 and 3.3 (above) are probably responsible for the observed changes and ultimately the decline of the SPA. Table 8 Qualifying features of the Stour and Orwell SPA and Ramsar site, and the Stour SSSI.

SPECIES NAME SPA Citation 1994

Ramsar Information Sheet 19949

SPA Review Information

2001

SSSI Citation 2003

Avocet Recurvirostra avosetta

Black-tailed godwit Limosa limosa islandica

Cormorant Phalacrocorax carbo

9 Updated 2005.

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SPECIES NAME SPA Citation 1994

Ramsar Information Sheet 19949

SPA Review Information

2001

SSSI Citation 2003

Curlew Numenius arquata

* Dark-bellied brent goose Branta bernicla bernicla

Dunlin Calidris alpina

Golden plover Pluvialis apricaria

Goldeneye Bucephala clangula

* Great crested grebe Podiceps cristatus

Grey plover Pluviatilis squatarola

Hen harrier Circus cyaneus

Knot Calidris canutus

* Mute swan Cygnus olor

* Lapwing Vanellus vanellus

Oystercatcher Haematopus ostralegus

Pintail Anas acuta

* Redshank Tringa totanus

Ringed plover Charadrius hiaticula

Scaup Aythya marila

* Shelduck Tadorna tadorna

Turnstone Arenaria interpres

Wigeon Anas penelope

*

* Non-qualifying nationally important populations of migratory species 7.3 STOUR AND ORWELL ESTUARIES RAMSAR SITE The Stour and Orwell Estuaries were listed under the Ramsar Convention as wetlands of international importance in 1994. As a matter of Government policy, Ramsar sites should be treated in the same way as SACs and SPAs. For the full Ramsar Information Sheet, see Appendix III.

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7.4 STOUR AND ORWELL ESTUARIES RECOMMENDED MARINE CONSERVATION ZONE

Marine Conservation Zones (MCZs) are areas which represent typical marine habitats and which may also contain rare or threatened species. The intention of the Marine & Coastal Access Act 200910 is that there should be a coherent network of Marine Protected Areas in UK waters, incorporating MCZs alongside other protected areas, including Special Areas of Conservation, Sites of Special Scientific Interest and Ramsar sites (wetlands of international importance designated under the Ramsar Convention).

In contrast to the designation of European sites, the designation of MCZs may take socio-economic factors into account, as long as these factors do not undermine the creation of the network. This will ensure that a network of sites can be achieved in a way that minimises adverse impacts on sea users and maximises benefits for nature conservation.

The management measures required within Marine Conservation Zones will be decided on a site-by-site basis and will depend on what the site has been designated for. In a similar way to protected areas on land, there will be sites where some activities are not allowed but others can occur, or where there are seasonal restrictions on activities rather than a complete ban. Not all sites will need the same management measures and there is no presumption that any specific type of activity will be restricted. There may however, be some sites where many activities are restricted.

The conservation objective for each MCZ will be set to ‘reference’, ‘recover’ or ‘maintain’ by Natural England, the Statutory Nature Conservation Body. This selection will inform the range of permitted activities into the future. Reference areas are controlled areas where minimal invasive human activity will be allowed. In order to contribute to the protection and recovery of the richness of our marine wildlife and environment, the UK Government is committed to establishing, by 2012, a strong, ecologically coherent and well managed network of marine protected areas, that is well understood and supported by sea users. In England this network will include the following types of Marine Protected Area: Sites of European and international importance:

• Special Areas of Conservation designated under the EC Habitats Directive; • Special Protection Areas designated under the EC Wild Birds Directive; and • Ramsar Sites designated under the Convention on Wetlands

Sites of national importance: • Marine Conservation Zones, as specified in the Marine and Coastal Access Act 2009;

and • Sites of Special Scientific Interest, designated under the Wildlife and Countryside Act

(as amended). Marine Conservation Zones will be aimed at conserving and promoting the recovery of:

• The range of marine biodiversity in UK waters; • Rare or threatened habitats and species;

10 Marine and Coastal Access Act 2009 2009 c. 23

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• Globally or regionally significant areas for geographically restricted habitats or species;

• Important aggregations or communities of marine species, particularly biodiversity ‘hotspots’;

• Areas important for key life cycle stages of mobile species, including habitats known to be important for reproduction and nursery stages;

• Areas contributing to the maintenance of marine biodiversity and ecosystem functioning in our seas; and

• Features of particular geological or geomorphological interest.

Habitat Features of Conservation Importance (FOCI) have been identified (Figure 8), which include Blue mussel beds, currently comprising 0.58 km2, but this figure may not be accurate (Natural England, 2011).

Figure 8 Map of Habitat FOCI of the Stour and Orwell rMCZ. Note the mussel beds in Holbrook Bay and up-estuary. From: Natural England (2011). There are no Habitat FOCI at or near the proposed locations of the mussel lays and given the proposed management and mitigation measures there are currently no foreseen or foreseeable adverse effects that might occur.

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7.5 STOUR ESTUARY SITE OF SPECIAL SCIENTIFIC INTEREST The Stour Estuary is a Site of Special Scientific Interest (SSSI) notified under section 28C of the Wildlife and Countryside Act 198111 as inserted by Schedule 9 to the Countryside & Rights of Way Act 200012. The following excerpts from the SSSI Citation are of relevance to the proposed Trial MSFO (the full citation can be viewed in Appendix IV): The Stour Estuary forms the eastern part of the Essex/Suffolk county boundary (Figure 9). It is a relatively simply structured estuary with a sandy outer area and a muddier inner section. The six main bays, Seafield, Holbrook and Erwarton on the north, and Jacques, Copperas and Bathside on the south, encompass most of the intertidal flats. The mud is extremely rich in invertebrates and this, coupled with its relative lack of disturbance, enables the estuary to support an internationally significant assemblage of wildfowl and wading birds. The shoreline is one of the most natural in the region, often with low cliffs. Those at Stutton and Wrabness contain nationally important geological exposures.

Figure 9 Map of the Stour Site of Special Scientific Interest. From: Natural England (2012).13

11 Wildlife and Countryside Act 1981 1981 c. 69 12 Countryside and Rights of Way Act 2000 2000 c. 37

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The main concentration of feeding birds tends to be in the bays. High tide roosts are located in various places, mostly on the sheltered parts of the northern shore and on the southern shore at Deep Fleet and the ‘tidal bank’ of Copperas Bay and Bathside Bay. The majority of the Redshank Tringa totanus, Black-tailed godwit Limosa limosa islandica and Dunlin Calidris alpina alpina feed in the muddier upper reaches, whereas most of the Grey plover Pluvialis squatarola and Knot Calidris canutus islandica congregate towards the seaward end. Curlew Numenius arquata, Ringed plover Charadrius hiaticula and Turnstone Arenaria interpres feed throughout the estuary. Wigeon Anas penelope graze on the beds of eelgrass Zostera spp. and green algae Enteromorpha spp. and winter in large numbers on a par with nearby Hamford Water. Pintail Anas acuta congregate with the Wigeon after arrival at Holbrook Bay, reaching peak numbers in mid-October and again in January-February. They prefer the upper and middle reaches where the very fine sediment favours their method of feeding and their major roost is on the saltings of Stutton Mill Creek. Shelduck Tadorna tadorna breed around the estuary and are present throughout the year apart from the August moult: maximum numbers occur in January. Shelduck also favour areas of high invertebrate density and concentrate in the upper reaches, roosting on the saltmarsh with other dabbling ducks. Wintering Brent geese Branta bernicla bernicla, feeding on eelgrass and green algae, prefer the lower reaches of the Essex shore. The wintering herd of Mute swans Cygnus olor feeds on the waste from the maltings at Mistley; their numbers peak in January and again in August when they are more widespread throughout the estuary, feeding particularly in Holbrook Bay. Thirteen species of wintering wildfowl and wader occur in qualifying numbers within the Stour Estuary: Grey plover, Knot, Dunlin, Redshank, Black-tailed godwit, Great crested grebe Podiceps cristatus, Cormorant Phalacrocorax carbo, Mute swan, Dark-bellied Brent goose, Shelduck, Pintail, Ringed plover and Curlew. Ringed plover, Dunlin and Redshank are regularly found using the Stour Estuary on autumn passage in nationally important numbers. The mudflats of the Stour Estuary also form an integral part of the estuarine system and are an essential feeding and roosting habitat supporting the nationally and internationally important numbers of waterbirds. In addition the estuary represents a good example of a sheltered muddy shore (including estuarine mud) within the Area of Search. Also present is a nationally important community of tide-swept lower shore mixed substrata with sponges, ascidians and red algae. The site contains good examples of mixed substrata and estuarine muds for the Area of Search. Many of the individual biotopes in the Stour are highly rated, often as a result of their relatively high species richness and large extent. Both of these habitat features are nationally restricted. There is an extensive area of estuarine sediments and the expected range of zonation of mixed substrata and estuarine sediments are present, including a clear variation in the composition of sediment communities along the salinity gradient up the estuary.

13 http://www.sssi.naturalengland.org.uk/Special/sssi/sssi_details.cfm?sssi_id=1004172 [accessed 18 March 2012]

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The site contains nationally scarce species at two locations within the estuary. These species are Starlet sea anemone Nematostella vectensis and Tentacled lagoon worm Alkmaria romijni. Of the ten estuaries in the Area of Search, the Stour is the only one to contain N. vectensis. Both species are listed in Schedule 5 of the Wildlife & Countryside Act 1981 (as amended). Natural England’s Views about Management (VAM) is not yet available for this SSSI.14 Relevant operations in respect of this proposal potentially likely to damage the special scientific interest of the site are listed in Table 9 (for full list see Appendix V). Table 9 Operations potentially likely to damage the special scientific interest of the Stour Estuary SSSI

OLD1004172 Ref. No. Type of Operation

9 The release into the site of any wild, feral or domestic animal*, plant or seed. 16b Coastal fishing or fisheries management and seafood or marine life collection, and

changes in coastal fishing practice or fisheries management and seafood or marine life collection, including the use of traps or fish cages.

26 Use of vehicles or craft likely to damage or disturb the fauna and flora of the Estuary.

* ‘Animal’ includes any mammal, reptile, amphibian, bird, fish or invertebrate. The following advice concerns due legal process under s28I of the Wildlife & Countryside Act 1981 (as amended): Before consenting the carrying out of operations likely to damage the special interest (OLDSI), any of the flora, fauna or geological or physiographical features by reason of which a SSSI is of special interest, the DEFRA will need to give notice of the proposed operations to Natural England (NE), even if the operations will not take place on land included in a SSSI. The DEFRA will need to wait until the expiry of the period of 28 days from the date of that notice before deciding whether to give its consent, unless NE has notified the DEFRA that it need not wait until then. The DEFRA will need to take any advice received from NE into account-

(a) in deciding whether or not to permit the proposed operations, and

(b) if it does decide to do so, in deciding what (if any) conditions are to be attached to the permission.

If NE advises against permitting the operations, or that certain conditions should be attached, but the DEFRA does not follow that advice, the DEFRA-

(a) will need to notify NE of the terms and conditions of its consent and will need to include a statement of how (if at all) the DEFRA has taken account of NE’s

14 http://www.sssi.naturalengland.org.uk/Special/sssi/sitedocuments.cfm?type=vam&sssi_id=1004172 [accessed 18 March 2012]

43

advice, and

(b) cannot grant a permission which would allow the operations to start before the end of the period of 21 days from the date of that notification.

Notwithstanding the aforesaid, given the proposed locations and sizes of the mussel lays and the anticipated intensity of the operations, and in view of the proposed management and mitigation measures there are currently no foreseen or foreseeable adverse effects that might compromise legal features of the SSSI. 7.6 BAP PRIORITY HABITAT: SHELTERED MUDDY GRAVELS ‘Sheltered muddy gravels are a UK Biodiversity Action Plan (BAP) priority habitat, and they are also listed for Section 41 of the Natural Environment and Rural Communities (NERC) Act 2006 as being ‘of principal importance for the purpose of conserving biodiversity in England’ (UK BAP, 2008). Sheltered muddy gravel habitats occur principally in estuaries, rias and sea lochs, in areas protected from wave action and strong tidal streams. In fully marine conditions on the lower shore this habitat can be extremely species-rich because the complex nature of the substratum supports a high diversity of both infauna and epifauna. However, good quality examples of this habitat are very scarce. Polychaetes and bivalve molluscs are normally dominant and the most varied, but representatives of most marine phyla can be present. The fauna is often characterised by a large range in body size. As one moves into an estuary, with a consequent reduction in salinity, there is a marked reduction in species richness. Low salinity (mid to upper estuarine) muddy gravels have a lower, but distinctive, species diversity. This plan concentrates on the intertidal and shallow subtidal high salinity muddy gravel habitats. The carpet shell mollusc Venerupis senegalensis is often, though not necessarily, present and can sometimes occur in large numbers. The blunt gaper Mya truncata is another characteristic species. There are considerable variations in the composition of these communities depending upon the sediment composition and salinity regime present. Members of the fully saline community can include the tube-dwelling polychaetes Sabella pavonina, Myxicola infundibulum and Amphitrite edwardsi, the sipunculan worm Golfingia sp, the anemones Sagartia troglodytes and Cereus pedunculatus and the holothurian Labidoplax digitata. Burrowing deposit-feeding polychaetes such as Notomastus latericeus, Aphelochaeta marioni and Melinna palmata may be abundant throughout the salinity range. The presence of coarse gravel and stones at the sediment surface often provides a substratum for the attachment of a variety of fauna and epiflora, for example fucoids, ephemeral green algae with associated littorinids and filamentous red algae. Although the most diverse communities occur in fully saline conditions a number of different species can occur under reduced salinity (upper estuarine) conditions. Here, Mya arenaria may be present, with the polychaetes Neanthes virens and Cirriformia tentaculata, the Cockle Cerastoderma edule and the Native oyster Ostrea edulis. Oligochaetes and the Rag worm Hediste diversicolor usually dominate the upper estuarine low salinity muddy gravels. Intertidal mixed sediment,

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Relevant biotopes of intertidal mixed sediments: LS.LMx Littoral mixed sediment LS.LMx.GvMu Hediste diversicolor dominated gravelly sandy mud shores LS.LMx.Mx Species-rich mixed sediment shores LS.LMx.Mx.CirCer Cirratulids and Cerastoderma edule in littoral mixed sediment Relevant biotopes of subtidal mixed sediments: SS.SMx.IMx Infralittoral mixed sediment SS.SMx.IMx.CreAsAn Crepidula fornicata with ascidians and anemones on infralittoral coarse mixed sediment SS.SMx.IMx.SpavSpAn Sabella pavonina with sponges and anemones on infralittoral mixed sediment SS.SMx.IMx.VsenAsquAps Venerupis senegalensis, Amphipholis squamata and Apseudes latreilli in infralittoral mixed sediment The infralittoral sediment biotopes in the Stour Estuary belong to the SS.SMx.SMxVS SS.SMx.SMxVS Sublittoral mixed sediment in variable salinity (estuaries) group and not to the above listed SS.SMx.IMx Infralittoral mixed sediment group. Biotopes of the sheltered muddy gravels BAP habitat in the Stour occur predominantly in intertidal areas and not at or near the proposed locations of the mussel lays and given the proposed management and mitigation measures there are currently no foreseen or foreseeable adverse effects that might occur. 7.7 TENTACLED LAGOON WORM ALKMARIA ROMIJNI AND STARLET SEA

ANEMONE NEMATOSTELLA VECTENSIS Nationally scarce brackish water species have been found in these estuaries and two ENG FOCI species are already protected by the Stour Estuary SSSI: Starlet Sea Anemone Nematostella vectensis, typically found in creeks that run over the mudflats of both estuaries and near the head of the Stour, and the Tentacled Lagoon worm Alkmaria romijini, located near the head of the Stour Estuary (Worsfold, 2002). Both species are listed in Schedule 5 of the Wildlife & Countryside Act 1981, as amended. In the Stour Estuary neither species occurs at or near the proposed locations of the mussel lays. Furthermore, both species are either of low sensitivity or not sensitive at all in respect of increased suspended sediments, should sediment plumes arsing from mussel dredging penetrate that far up-estuary. Both species have either at least a high recoverability if not an immediate one following such an event. Given the proposed management and mitigation measures there are currently no foreseen or foreseeable adverse effects that might occur. Table 10 Sensitivities of Tentacled Lagoon worm Alkmaria romijini and Starlet Sea

Anemone Nematostella vectensis. Modified from White (2002) and Marshall & Jackson (2007).

Factor Intolerance Recoverability Sensitivity Evidence / Confidence

Tentacled Lagoon worm Alkmaria romijini

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Factor Intolerance Recoverability Sensitivity Evidence / Confidence

Substratum loss High Very high Low Smothering Intermediate Low High Low Suspended sediment (up) Low High Low Low Turbidity(up) Tolerant Very high Not sensitive Low Noise Insufficient

information Not relevant Insufficient

information Not relevant

Visual presence Insufficient information

Not relevant Insufficient information

Not relevant

Abrasion & phys disturbance Intermediate Low High Low Displacement High Low High Low Nutrient levels (up) Insufficient



Oxygenation (down) Low High Low High Introduction of non-natives Insufficient



Extraction of other species Insufficient information

Not relevant Insufficient information

Not relevant

Starlet Sea Anemone Nematostella vectensis Substratum loss High Very high Low Smothering Intermediate High Low Low Suspended sediment (up) Low Immediate Not sensitive Low Turbidity (up) Tolerant Not relevant Not sensitive High Noise Tolerant Not relevant Not sensitive High Visual presence Tolerant Not relevant Not sensitive High Abrasion & phys disturbance Intermediate High Low Low Displacement Tolerant Not relevant Not sensitive Low Nutrient levels (up) Insufficient

information Insufficient information


Not relevant

Oxygenation (down) Intermediate High Low Low Introduction of non-natives Insufficient

information Insufficient information


Not relevant

Extraction of other species Intermediate High Low Very low 8 STATEMENT TO INFORM A HABITATS REGULATIONS ASSESSMENT 8.1 BACKGROUND Under Regulation 9(5) of The Conservation of Habitats and Species Regulations 2010 (as amended) (‘The 2010 Regulations’), a competent authority must have regard to the requirements of the EC Habitats and Species Directive (92/43/EEC) when exercising its functions. Article 6(3) of the Directive requires that any plan or project likely to have a significant effect on a SAC (or by virtue of Article 7, an SPA) and which is not directly connected with or necessary to the management of the SAC or SPA, shall be subject to an appropriate assessment of its implications for the SAC or SPA in view of the site’s conservation objectives. In relation to certain categories of plan or project, that obligation is transposed by Part 6 of The 2010 Regulations, in particular by Regulation 61.

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As a matter of Government policy, Ramsar sites (sites listed under the Ramsar Convention as wetlands of international importance) should be treated in the same way as SACs and SPAs, including in particular in relation to the consideration of plans and projects likely to affect them. The following is a statement to inform the Habitats Regulations Assessment (HRA) for the proposed Trial Mussel SFO in the Stour Estuary by the UK Government for relevant features of the Stour and Orwell Estuaries SPA and Ramsar Site under Regulation 61 of The 2010 Regulations. 8.2 ASSESSMENT OF POTENTIAL IMPACTS ON SITE INTEGRITY AND

RECOMMENDED MITIGATION MEASURES “Test of Likely Significant Effect for the internationally important populations of regularly occurring (a) Annex 1 and (b) migratory bird Species”: The CONSERVATION OBJECTIVE for the internationally important populations of regularly occurring (a) Annex 1 and (b) migratory bird species:

Subject to natural change, maintain in favourable condition the habitats for the internationally important populations of the regularly occurring (a) Annex 1 and (b) migratory bird species, under the Birds Directive, in particular -

• Intertidal mudflat • Saltmarsh TABLE 11 ‘FAVOURABLE CONDITION TABLE’ FOR THE INTERNATIONALLY IMPORTANT

POPULATIONS OF REGULARLY OCCURRING ANNEX 1 AND MIGRATORY BIRD SPECIES

Detailed definitions of how to recognise favourable condition of intertidal mudflat and saltmarsh sub-features:

Is the plan or project likely to undermine the conservation objective? If ‘yes’, give brief details.

Mitigation of adverse effects

Will mitigation remove risk of adverse effects?

Extent and distribution of habitat

No decrease in extent of habitats, from an established baseline, subject to natural change.

Yes;

(a) potential for deposition of seed mussel on adjacent intertidal mudflats;

(b) potential for infilling / smothering of existing intertidal depressions (‘mud pools’) and choking of tidal creeks;

(c) possible long-term changes to hydrodynamics and

(a) Relaying of seed mussel in the 5 proposed subtidal plots and below the maximum foraging water depth of Mute swans only;

(b) total area of seed mussel relaying not to exceed 84 ha;


(d) no deposition of

Yes

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associated sediment processes;

(d) increase in sedimentation (mussel faeces & pseudo-faeces, increased natural deposition due to reduced bed flow);

(e) deposition of mussel shell debris;

(f) import of other material (e.g. coarse sediments brought in with seed mussel);

(g) possible changes to intertidal morphology; and

(h) increase in nutrient loading, as nutrients are being released from faeces & pseudo-faeces, and retained within the system rather than being flushed out with the tide.

seed mussel on adjacent intertidal mudflats and sandflats or within tidal creeks;

(e) targeted precision relaying of seed mussel by boat only;

(f) surveillance with drop-down video of adjacent areas of the TMSFO; and

(g) implementation of all biosecurity measures listed in Section 5 (above).

Disturbance No significant reduction in numbers or displacement of wintering birds from established baseline, subject to natural change.

Yes;

Waders and wildfowl could be subject to low levels of disturbance when using the adjacent intertidal mudflats or when ducks, geese or swans are present on open water. See also ‘Food availability’ (below).

(a) Relaying of seed mussel in the 5 proposed subtidal plots and below the maximum foraging water depth of Mute swans only;

(b) no deposition of seed mussel on adjacent intertidal mudflats and sandflats and within tidal creeks;

(c) a 3 knots maximum boat speed limit when working the mussel lays, with a 8 knots maximum speed limit throughout the remainder of the Stour Estuary; and

(d) implementation of all measures listed under

Yes

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‘Extent and distribution of habitat’ (above) and ‘Food availability’ (below).

Obstructions to view lines No increase in obstructions to existing bird view lines, subject to natural change.

No N/A N/A

Food availability Presence and abundance of prey species should not deviate significantly from an established baseline, subject to natural change.

Yes;

(a) mussels may out-compete indigenous epifauna;

(b) mussels will attract epifaunal predator species (e.g. starfish and green crab);

(c) prey species populations may also be adversely affected by predation by the mussels and / or increased numbers of mussel predators;

(d) import of mussel into the estuary will increase the reproductive potential of the species within the estuary possibly resulting in increased recruitment and impact on other areas of the estuary; and

(e) risk of introduction of non-native species.

(a) Relaying of seed mussel in the 5 proposed subtidal areas and below the maximum foraging water depth of Mute swans only;

(b) total area of seed mussel relaying not to exceed 84 ha;


(d) no deposition of seed mussel on adjacent intertidal mudflats and sandflats or within tidal creeks;


(f) limited control of predators only;

(g) surveillance with drop-down video of adjacent areas of the TMSFO; and

(h) implementation of all biosecurity measures listed in Section 5 (above).

Yes

Saltmarsh vegetation characteristics

Vegetation height throughout areas used for roosting should not deviate significantly from an established baseline, subject

No N/A N/A

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to natural change. In summary, given the proposed locations and sizes of the five mussel lays of this Trial Mussel Several Fishery Order and the proposed husbandry methods of this native shellfish, and given the proposed management and mitigation measures, it may be concluded that there will be no adverse effect on site integrity, provided that these will all be implemented and adhered to. 9 CONSIDERATION OF ALTERNATIVES Alternative locations for subtidal and intertidal mussel bottom culture have been considered. The number and size of existing, intertidal mussel beds that could be commercially viable as a MSFO are very limited in South and West Wales. Mussel beds of sufficient size have generally formed on the hard substrata of glacial tills. Examples include Whiteford Point at the western end of the Burry Inlet and Salmon Scar Point near St Ishmael in the Three Rivers Estuary; both are situated within the Carmarthen Bay & Estuaries EMS. Both seed relaying and harvesting would be unduly laborious and cumbersome, in addition to impacts on geomorphological and biological features of interest, such as the glacial tills themselves with their particular hard substratum and rock pool epifauna. Any subtidal mussel bottom culture within an EMS would need to be subject to an HRA under Regulation 61 of The 2010 Regulations. There are currently no known areas within the three South and West Wales EMSs, i.e. Carmarthen Bay & Estuaries EMS, Pembrokeshire Marine EMS and Cardigan Bay EMS, that would not flag up ‘likely significant effect’ and ‘likely to undermine the COs for features of the site’. It is considered unlikely that any subsequent AA would be able to return an unequivocal ‘no adverse effect on site integrity’. At best, and in rare cases, it could possibly be inconclusive, but that would nevertheless still constitute a negative outcome of the AA. It is considered very highly unlikely that Regulation 62 of The 2010 Regulations, i.e. granting permission for Imperative Reasons of Overriding Public Interest (IROPI), could be evoked in this case (Birdlife International, 2010). Consequently, subtidal areas within EMSs were not considered further. Subtidal areas outwith EMSs are also limited and are either already subject to Mussel SFOs and an associated abundance of the non-native mussel predator / pest Crepidula fornicata (Slipper limpet) (e.g. Swansea Bay), or are ‘virgin’ seabed (e.g. Oxwich Bay) in closer proximity to an EMS than the proposed location in Newport Bay. However, mussel beds are important in sediment dynamics of coastal systems. They collect sediment and are able to keep up with sea level rise (OSPAR, 2010). They protrude from the surrounding mudflats and are important as food source for birds. In the Waddensea, for instance, 25 % of the bird numbers used to occur on mussel beds which only occupied 3 % of the area (Zwarts, 1991). The morphological structure of littoral areas is also enhanced by the

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mussel beds even where absent, as remnants are visible as elevations of clay banks or shell layers. In the Waddensea these are often a good basis for new spatfall. Very old beds may also stabilise creek patterns because clay and shell layers are relatively erosion resistant. In 2009, the Anglian River Basin Management Plan assessed the Stour and Orwell Estuaries SPA as of not meeting its environmental objectives as required by Article 4(1c) of the EU Water Framework Directive15 (Table 12). Article 4(1c) states “Member states shall achieve compliance with any standards and objectives at the latest 15 years after the date of entry into force of this Directive, unless otherwise specified.” The reason why the SPA failed to meet its objectives is stated as ‘coastal squeeze’ (see Sections 3.1 and 3.3 above).

Table 12 WFD assessment of Stour and Orwell SPA. From: Environment Agency (2009). Looking at the Shoreline Management Plan (SMP2) policies suggested for the next 20 years for the shoreline of the Stour Estuary (Figure 10), it becomes apparent that only very limited stretches will be held, with many more showing policies of managed realignment or no active intervention. Consequently there would be merit in investigating the benefits that mussel beds could provide within the contexts of flood defences and coastal protection. The areas to be investigated should only include those marked in green in Figure 11 where bait digging is currently allowed, even in the winter months when migratory birds are in residence.

15 Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy.

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Figure 10

Map of preferred SMP2 management policy options for the Stour and Orwell Estuaries (present day to 2025). From: Environment Agency (2010a).

Figure 11

Map from “Looking after our Estuaries - A voluntary code of conduct for users of the mudflats on the Stour and Orwell Estuaries” (Ipswich Borough Council, 2010).

Figure 12 illustrates recent research undertaken in The Netherlands investigating the benefits of mussel beds within a coastal defence context.

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However, whilst there are merits in investigating this alternative approach further, whereby a permanent strip of mussel reef would remain on the seaward side of the mudflat, with mussel cultivation taking place in its lee, it was outside the scope of this Environmental Statement. It was concluded to adopt a precautionary approach and pursue a limited number of subtidal mussel lays only.

(a) Experimental mussel bed

(b) Reference transect without mussel bed illustrating the erosional lowering of the intertidal flat.

(c) Transect with mussel bed illustrating the build-up of sediment in the lee of the reef.

Figure 12

Recent research in The Netherlands: ‘The use of an ecosystem engineer in coastal defence’ (from: Walles et al., 2011).

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9 CONCLUSIONS Given all of the detailed considerations in Sections 1 to 8 above, it may be concluded with a high degree of confidence that this Environmental Statement demonstrates that the current proposal will result in an environmentally benign mussel fishery, whilst possibly even improving subtidal BAP biotopes that are currently being degraded by the presence of invasive non-native Slipper limpets. REFERENCES Anonymous (1999) UK Biodiversity Group: tranche 2 action plans: volume V- maritime species and habitats. English Nature, Peterborough, UK. Anonymous (2008) Shellfish Industry Development Strategy - A Case for Considering MSC Certification for Shellfish Cultivation Operations; Draft April 2008 Armitage, M.J.S. & M.M. Rehfisch (2002) Assessing Waterbird Population trends on the Stour and Orwell Estuaries SPA. BTO Research Report 297. Thetford. Armitage, M.J.S., Austin, G.E., Ravenscroft, N.O.M. & M.M. Rehfisch (2003) Towards determining the causes of declines in waterbird numbers on the Stour and Orwell estuaries SPA. BTO Research Report No. 338 (report to Posford Haskoning Ltd). Ashelby, C.W. (2005) Intertidal Fish and Shrimp Surveys of the Stour and Orwell Estuaries: Analysis of Regular Intertidal Trawls taken between December 2003 and December 2004. Unicomarine Report HHAYOct2005 to Harwich Haven Authority. Unicomarine Ltd, Letchworth. Austin, G. & M.M. Rehfisch (2005) Shifting non-breeding distribution of migratory fauna in relation to climate change. Global Change Biology 11, 31-38. Banks, A.N., Collier, M.P., Austin, G.E., Hearn, R.D., & A.J. Musgrove (2006) Waterbirds in the UK 2004/05: The Wetland Bird Survey. BTO/WWT/RSPB/JNCC, Thetford. Barnes, R.S.K. & R.N. Hughes (1992) An introduction to marine ecology. Oxford: Blackwell Scientific Publications. Beardall, C.H., Dryden, R.C. & T.J. Holzer (1991) The Suffolk Estuaries: A report by the Suffolk Wildlife Trust on the wildlife and conservation of the Suffolk Estuaries. Published by Segment Publications for the Suffolk Wildlife Trust, 1991. Birdlife International (2010) Position paper of the Birds and Habitats Directives Task Force on the approach to alternative solutions and imperative reasons of overriding public interest under Article 6(4) of the EU Habitats Directive. Adopted by BHDTF on 12 April 2010. BMPA (2008) Code of Good Practice for mussel seed movements. Primary authors: James Wilson (Bangor Mussel Producers Association) & Kate Smith (Countryside Council for Wales). Version 1: July 2008.

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Budd, G. (2008) Hediste diversicolor. Ragworm. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/speciessensitivity.php?speciesID=3470 Budd, G. & J. Hughes (2005) Nephtys hombergii. A catworm. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/speciessensitivity.php?speciesID=3897 Budd, G. & W. Rayment (2001) Macoma balthica. Baltic tellin. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/speciesbenchmarks.php?speciesID=3749 Burton, N.H.K., Paipai, E., Armitage, M.J.S., Maskell, J.M., Jones, E.T., Struve, J., Hutchings, C.J. & M.M. Rehfisch (2000a) Effects of reductions in organic and nutrient loading on bird populations in estuaries and coastal waters of England and Wales. Phase 1 report. BTO Research Report 267, Thetford. Burton, N.H.K., Armitage, M.J.S., Musgrove, A.J. & Rehfisch (2002b) Impacts of man-made landscape features on numbers of estuarine waterbirds at low tide. Environmental Management, 30, 857-864. Cefas (2009) Shellfish Biosecurity Measures Plan. Guidance and templates for shellfish farmers. Biosecurity Guidance. This publication is also available @ www.efishbusiness.co.uk Colclough, S. (2010) Marine Fish Nursery Function in the Stour (Suffolk) Estuary. Environment Agency, United Kingdom. Connor, D.W., Dalkin, M.J., Hill, T.O., Holt, R.H.F. & W.G. Sanderson (1997) Marine biotope classification for Britain and Ireland. Vol. 2. Sublittoral biotopes. Joint Nature Conservation Committee, Peterborough, JNCC Report no. 230, Version 97.06. Connor, D.W., Allen, J.H., Golding, N., Howell, K.L., Lieberknecht, L.M., Northen, K.O. & J.B. Reker (2004) The Marine Habitat Classification for Britain and Ireland. Extracts from Littoral and Sublittoral Sediment Sections. Version 04.05 JNCC, Peterborough ISBN 1 861 07561 8 (internet version) www.jncc.gov.uk/MarineHabitatClassification Cooper, N., Skrzypczak, T. & F. Burd (2000) Erosion of the saltmarshes of Essex between 1988 and 1998. Report to the Environment Agency. Drinnan, R.E. (1957) The winter feeding of the oystercatcher (Haematopus ostralegus) on the edible cockle (Cardium edule). J. Animal Ecol., 26: 441-469. Dyer, M.F. (2005) Stour and Orwell Estuaries Fish and Shrimp Monitoring: Summary of Surveys and Results: 1999 – 2004. Unicomarine report HHAFishSum2005 to Harwich Haven Authority. Unicomarine Ltd, Letchworth.

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Dyer, M.F., C.W. Ashelby and T.M. Worsfold (2004) A comparison of the sediment characteristics of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHASED04 to Harwich Haven Authority, January 2004. Dyer, M.F. & T.M. Worsfold (2004) Comparison of the intertidal benthos of the Stour and Orwell estuaries between 1997 and 2003. Unicomarine Report HHAStrOrw03int to Harwich Haven Authority, February 2004. Elliot, M., Nedwell, S., Jones, N.V., Read, S.J., Cutts, N.D. & K.L. Hemingway (1998) Intertidal sand and mudflats & subtidal mobile sandbanks (Vol. II). An overview of dynamic and sensitivity for conservation management of marine SACs. Prepared by the Scottish Association for Marine Science for the UK Marine SACs Project. Elliott, M., Burdon, D., Callaway, R., Hutchinson, T., Longshaw, M., Maud, J., Malham, S., Mazik, K., Otto, S., Palmer, D., Rossiter, T., Smith, T., Stephens, M. & A. Wither (2012) Burry Inlet Cockle Mortalities Investigation 2009-2011. Technical Report to Environment Agency Wales, Institute of Estuarine and Coastal Studies, University of Hull. English Nature (2003) Stour Estuary Site of Special Scientific Interest – Citation. English Nature, Peterborough, 9 April 2003, 4pp.. Environment Agency (2009) River Basin Management Plan, Anglian River Basin District, Annex D: Protected areas. December 2009, p.109. Environment Agency (2010a) Essex and South Suffolk SMP2. Produced by the Environment Agency on behalf of the Client Steering Group. Final version 2.4, 15 October 2010. Figure 4-1, p.109. Environment Agency (2010b) Essex and South Suffolk SMP2. Produced by the Environment Agency on behalf of the Client Steering Group. Appendix M, Habitats Regulations Assessment Report. Draft Final Report version 2.1, October 2010. Section 5.1.1 Management Unit A – Stour and Orwell, p.32. Goss-Custard, J.D., Jones, R.E. & P.E. Newberry (1977a) The ecology of the Wash. 1. Distribution and diet of wading birds (Charadrii). Journal of Applied Ecology, 14, 681-700. Goss-Custard, J.D., Jenyon, R.A., Jones, R.E., P.E. Newbery, and R. le B. Williams (1977b) The Ecology of the Wash. II. Seasonal Variation in the Feeding Conditions of Wading Birds (Charadrii). J. Appl. Ecol. 14, 701–719. Goss-Custard, J.D., Clarke, R.T., Durell, S.E.A. le V. dit, Caldow, R.W.G. & B.J. Ens (1995) Population consequences of winter habitat loss in a migratory shorebird. II. Model predictions. Journal of Applied Ecology, 32, 337-351. Hall, S.J. & Harding, M.J.C., (1997). Physical disturbance and marine benthic communities: the effects of mechanical harvesting of cockles on non-target benthic infauna. Journal of Applied Ecology, 34, 497-517.

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Hiscock, K. (2006) Ascidiella scabra. A sea squirt. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 01/04/2012]. Available from: http://www.marlin.ac.uk/speciessensitivity.php?speciesID=2628 Hiscock, K., Langmead, O., Warwick, R. & A. Smith (2005) Identification of seabed indicator species to support implementation of the EU Habitats and Water Framework Directives. Second edition. Report to the Joint Nature Conservation Committee and the Environment Agency from the Marine Biological Association. Plymouth: Marine Biological Association. JNCC Contract F90-01-705. 77pp.. (The report can be accessed at: http://www.marlin.ac.uk/PDF/MBA_Indicators_2005.pdf) Holt, C.A., Austin, G.E., Calbrade, N.A., Mellan, H.J., Mitchell, C., Stroud, D.A., Wotton, S.R. & Musgrove, A.J. (2011) Waterbirds in the UK 2009/10: The Wetland Bird Survey. BTO/RSPB/JNCC, Thetford. HR Wallingford (1994) Wave prediction studies for Harwich Harbour. HR Wallingford Report EX 3030, June 1994. HR Wallingford (2001a) Harwich Harbour Strategic Studies: Analysis of cores obtained from the Stour Estuary (February 2001). HR Wallingford Report EX 4412. HR Wallingford (2001b) Harwich Harbour Strategic Studies: ADCP measurements of currents and sediment flux in Harwich Harbour (February 2001). HR Wallingford EX 4423. HR Wallingford (2001c) Harwich Harbour Strategic Studies: Suspended sediment monitoring in the Stour and Orwell estuaries (December 1998 – March 2001). HR Wallingford EX 4425. HR Wallingford (2001d) Harwich Harbour Strategic studies: Intertidal bed level monitoring (November 2000 – March 2001). HR Wallingford Report EX 4397. HR Wallingford (2001e) Harwich Harbour Strategic studies: The effect of past changes in the Stour Estuary on wave conditions. HR Wallingford Report EX 4411. HR Wallingford (2001f) Harwich Harbour Strategic Studies: Suspended sediment monitoring in the Stour and Orwell estuaries (December 1998 – March 2001). HR Wallingford EX 4425. HR Wallingford (2001g) Bathside Bay Development Studies: 3D Tidal flow modelling. HR Wallingford Report EX 4429. Ipswich Borough Council (2010) New code of conduct to protect mudflats. Ipswich Borough Council, Latest News, Published Tuesday 12th October 2010 at http://www.ipswich.gov.uk/site/scripts/news_article.php?newsID=502 [accessed on 12 March 2012]. The Voluntary Code can be downloaded from this webpage. Lee, C.S. (2005) Application of biosecurity in aquaculture production systems. Pages 66-75. Y. Sakai, J.P. McVey, D. Jang, E. McVey, and M. Caesar, editors. Aquaculture and Pathobiology of Crustacean and Other Species. Proceedings of the Thirty-Second U.S. Japan Symposium on Aquaculture. Davis and Santa Barbara, CA, 17, 18, and 20 November 2003. UJNR Technical Report 32. NOAA Research, Silver Spring, MD.

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Longshaw, M. & S. Otto (in draft) Atypical Cockle Mortalities in the Burry Inlet, South Wales. Centre for Environment, Fisheries and Aquaculture Science, Shellfish News, Number 32, Autumn/Winter 2012, pp. ?-?. Marshall, C. & A. Jackson (2007) Nematostella vectensis. Starlet sea anemone. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 26/07/2012]. Available from: <http://www.marlin.ac.uk/speciessensitivity.php?speciesID=3860>

Meire, P.M. (1993) The impact of bird predation on marine and estuarine bivalve populations: a selective review of patterns and underlying causes. In Bivalve filter feeders in estuarine and coastal ecosystem processes (ed. R.F. Dame). NATO ASI Series, Springer Verlag. Natural England (2011) Stour & Orwell Estuaries rMCZ no 2 - Marine Conservation Zone: Selection Assessment Document. Version V1.0 07.09.11, Draft final recommendations refined by the RSG and Local groups in July 2011 and finalised by the RSG 2/3 August 2011. OSPAR Commission (2010) Intertidal Mytilus edulis beds on mixed and sandy sediments. Quality Status Report 2010, Case Reports for the OSPAR List of threatened and/or declining species and habitats – Update. [This is an updated version of the case report that appears in the OSPAR Publication: Case Reports for the OSPAR List of threatened and/or declining species and habitats. OSPAR Publication number 2008/358. Information in the case report has been updated by Dr Susan Gubbay under contract to OSPAR.] Posford Duvivier Environment (1998) Harwich Haven Approach Channel Deepening. Appropriate Assessment. Report to Harwich Haven Authority. Pruder, D.G. (2004) Biosecurity: application in aquaculture. Aquacultural Engineering 32, 3–10. Ratcliffe, D.A. (1977) A Nature Conservation Review: the Selection of Sites of Biological National Importance to Nature Conservation in Britain. 2 Volumes. Cambridge University Press. Ravenscroft, N., Parker, B., Vonk, R. & M. Wright (2007) Disturbance to waterbirds wintering in the Stour-Orwell estuaries SPA. A Report from Wildside Ecology to the Suffolk Coast and Heaths Unit, 74pp.. Rayment, W. (2007) Aphelochaeta marioni. A bristleworm. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/speciessensitivity.php?speciesID=2560 Rayment, W.J. (2008a) Crepidula fornicata and Aphelochaeta marioni in variable salinity infralittoral mixed sediment. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 31/03/2012]. Available from: http://www.marlin.ac.uk/habitatsensitivity.php?habitatid=52&code=1997

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Rayment, W.J. (2008b) Hediste diversicolor and Macoma balthica in sandy mud shores. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/habitatsensitivity.php?habitatid=209&code=1997 Rehfisch, M.M., Insley, H. & R. Swann (2003) Fidelity of overwintering shorebirds to roosts on the Moray Firth, Scotland: implications for predicting impacts of habitat loss. Ardea, 91, 53-70. Reise, K. (1977) Predator exclusion experiments in an intertidal mud flat. Helgolaender Meeresuntersuchungen 30, 263-271. Royal Haskoning (2003) Felixstowe South Reconfiguration - Environmental Statement. Hutchison Ports (UK) Ltd, November 2003. The ES can be downloaded from http://www.hict.co.uk/content/theapplication/statement.asp Smith, C. (1986) Suspended sediment controls in the Orwell Estuary Study. PhD Thesis for the University of East Anglia, August 1986. Suffolk Wildlife Trust (2007) Ornithological Monitoring of the Stour and Orwell Estuaries Special Protection Area: Winters 1999/2000 to 2006/2007. Report to Harwich Haven Authority. Symonds, F.L. & D.R. Langslow (1986) The distribution and local movements of shorebirds within the Moray Firth. Proceedings of the Royal Society Edinburgh, 91B, 143-168. Tyler-Walters, H. (2007) Cerastoderma edule. Common cockle. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/speciessensitivity.php?speciesID=2924 Tyler-Walters, H. (2008) Arenicola marina. Blow lug. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/03/2012]. Available from: http://www.marlin.ac.uk/speciessensitivity.php?speciesID=2592 UK BAP (2008) UK Biodiversity Action Plan - Priority Habitat Descriptions: Sheltered Muddy Gravels. BRIG (ed. Ant Maddock) 2008. University of Newcastle (2000) Erosion of the saltmarshes of Essex between 1988 and 1998. Report prepared for Environment Agency Anglian Region by the Coastal Geomorphology Partnership and the Department of Marina Sciences and Coastal Management, University of Newcastle. Walles, B., Ysebaert, T., Troost, K., Herman, P. & A. Smaal (2011) The use of an ecosystem engineer in coastal defense. Unpbl. presentation, 14th International Conference on Shellfish Restoration 2011, 23-27 August 2011, University of Stirling, Stirling.

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White, N. (2002) Alkmaria romijni. Tentacled lagoon worm. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 26/07/2012]. Available from: <http://www.marlin.ac.uk/speciessensitivity.php?speciesID=2453> Worsfold, T.M. (2002) Review of the Biology of the Most Important Fish and Shrimp Species in the Stour and Orwell Estuaries with Comments on their Local Occurrence. Unicomarine Report HHAFishRev02 to Harwich Haven Authority. Unicomarine Ltd, Letchworth. Worsfold, T.M. (2005) Stour, Orwell and Harwich approaches benthos: review of data commissioned by Harwich Haven Authority, biotope distribution update and partial review of current knowledge for the area. Unicomarine Report HHABiot05 to Harwich Haven Authority, November 2005. Wright, M.T. (2001) Orwell Estuary – Systematic review of waterbirds. English Nature Research Report No 381. Yates, M.G., Goss-Custard, J.D., McGrorty, S., Lakhani, K.H., Durrel, S.E.A. le V. dit, Clarke, R.T., Riggin, W.E., Moy, I., Yates, T., Plant, R.A. & A.J. Frost (1993) Sediment characteristics, invertebrate densities and shorebird densities on the inner banks of the Wash. Journal of Applied Ecology, 30, 599-614. Zwarts, L. & P. Esselink (1989) Versatility of male curlews Numenius arquata preying upon Nereis diversicolor: deploying contrasting capture modes dependent on prey availability. Marine Ecology Progress Series, 56, 255-269.

APPENDIX I Habits and habitat requirements of nationally and internationally important waders and wildfowl present in the Stour and Orwell Estuaries. Species are listed in alphabetical order, and not in order of preference / importance.

Habitat requirements Feeding ground Species Biological status

(site specific) Substrate & vegetation Food Roosting site Staging area

Nesting site

Avocet Recurvirostra avosetta

Breeding Wintering

Coastal lagoons Aquatic insects and their larvae, crustaceans and worms.

Black-tailed Godwit Limosa limosa islandica

Wintering Summer: Damp grassland, muddy pools & ditches; Winter: estuarine mud (feeds whilst wading in quite deep water)

Summer: earthworms & tipulid larvae, insect larvae, molluscs & other benthic invertebrates; Winter: oligochaete, polychaete worms and bivalves.

Winter: high-tide coastal / estuarine margins; Inland wet grassland

Iceland, occasionally in Britain & Ireland: wet meadows, coastal grazing marshes & moorland bogs; well-grazed grassland with high water table being preferred

Cormorant Phalacrocorax carbo

Breeding Wintering

Rocky shores, coastal lagoons and estuaries; also increasingly inland reservoirs, lakes and gravel pits.

Fish

Curlew Numenius arquata

Wintering Feed in a wide range of habitats, including fields as well as intertidal & coastal marshes

Wide range of medium-large invertebrates; Intertidal: most common bivalve molluscs, polychaete worms & crustacea, incl. Carcinus. Inland: adult & larval insects, especially earthworms, some berries on breeding grounds

Form large roosting flocks. Roost in high-tide coastal / estuarine margins as well as fields.

Britain: upland areas, favouring moist, poorly drained moors & heaths; also on rough grassland

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Nesting site

Dark-bellied bBrent goose Branta bernicla bernicla

Wintering Estuaries and saltmarshes Vegetation, especially eel-grass

Dunlin Calidris alpina

Wintering In winter, and on passage, feed over all shore levels, but especially on middle shore (prefareably intertidal).

Wide range of small prey species, predominantly Nereis diversicolor & Hydrobia ulvae, but also many other small polychaete worms, gastropod & bivalve molluscs, plus crustaceans

Form very large flocks at roost, on passage & in winter

North & west Scotland: wet upland moorland, with pools and patches of very short vegetation, and in wet coastal zones

Goldeneye Bucephala clangula

Wintering In winter on lakes, large rivers and sheltered coasts.

Mussels, insect larvae, small fish and plants

Golden plover Fluvialis apricaria

Wintering Lowland fields. Worms and beetles. Form large flocks, often in the company of lapwings.

Great crested grebe Podiceps cristatus

Breeding Lowland lakes, gravel pits, reservoirs and rivers. Also found along coasts in winter.

Mainly fish.

Greenshank Tringa nebularia

Migratory On migration it can be found across the UK, inland around lakes and freshwater marshes, as well as at coastal wetlands and estuaries, with the largest numbers close to the coast.

Worms, snails and fish.

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Nesting site

Grey plover Pluviatilis squatarola

Wintering Migratory

Require large, open mudflats; feed mainly on middle and upper shore levels on estuaries; establish low tide feeding territories, others feed in flocks, especially in severe weather.

Wide range of food items, but predominantly polychaete worms (e.g. Nereis, Arenicola, Notomastus)

Form large roosting concentrations

Western Russia east to eastern Canada: on arctic tundra; birds using the East Atlantic Flyway breed in western Russia east to the Taimyr peninsula

Knot Calidris canutus

Wintering Migratory

Require large, open mudflats.

Specialist feeder on marine bivalve molluscs, particularly Macoma balthica, Mytilus edulis & Cerastoderma spp.; items range 3-15 mm in length; spat of Mytilus edulis prominent in diet during pre-migration build-up of weight

Form very large, dense flocks both on feeding grounds & at roosts

High Arctic nest sites in a variety of different habitats

Mallard Anas platyrhynchos

Breeding Wherever there are suitable wetland habitats, although scarcer in upland areas.

Seeds, acorns and berries, plants, insects and shellfish.

Mute swan Cygnus olor

Breeding Water plants, insects and snails.

Lapwing Vanellus vanellus

Breeding Worms and insects.

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Nesting site

Oystercatcher Haematopus ostralegus

Wintering Migratory

Outside breeding season associated with sandy estuaries, beds of cockles & mussels, & rocky coasts; small number also on coastal pastures

Mainly lamellibranch molluscs (Cerastoderma edule, Mytilus edulis & Scrobicularia plana); also many Patella vulgaris on rocky coasts; on pasture inland also take variety of invertebrates, incl. earthworms, larvae of butterflies & moths, beetles, flies, adult moths & earwigs

Form very large, dense flocks both on feeding grounds & at roosts

Britain: coastal habitats, but also increasingly inland along river valleys

Pintail Anas acuta

Wintering Migratory

Wide variety of substrates, from water-based, cereal fields, marshlands, rough pasture to estuarine sand & mudflats. Eleocharis palustris (preferred)

Mainly cereals & seeds, principally Eleocharis palustris; also various water-plants, insects, larvae, crustaceans, leeches & tadpoles; on estuaries the mollusc Hydrobia is the most important food.

Britain: wide variety of wetland habitats (close to water), but mainly areas of low-lying marshland & rough pasture intersected with ditches; usually in short grass, low Calluna, scattered Juncus or Ammophila

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Nesting site

Redshank Tringa totanus

Breeding Wintering Migratory

Coastal substrates, from rocky shores, estuarine sand & mudflats to pastures (but chiefly coastal saltmarsh & grazing marsh); feeding range extends higher up the shore than for most waders

Summer: feed mostly small insects & aquatic invertebrates; Winter: principally estuarine invertebrates such as Nereis diversicolour, Hydrobia ulvae & Corophium volutator also fish and earth worms.

Form small to medium-sized flocks; roosting usually on sparsely vegetated islets, spits & the banks of pools & creeks, but also among Spartina grass, and on bare arable fields (on highest spring tides)

Coastal: highest densities on middle & upper parts of saltmarshes, locally on coastal grazing marshes & damp machair; Inland: in damp pastures, on rough grazing land & lowland heaths, moorland & in cereal crops; access to shallow water required (estuarine creeks, pools & flooded ditches)

Ringed plover Charadrius hiaticula

Wintering Coastal substrates, in particular beaches.

Flies, spiders, marine worms, crustaceans, molluscs.

Breeds on beaches around the coast, but has also now breeding inland in sand and gravel pits and former industrial sites.

Scaup Aythya marila

Wintering Intertidal, estuarine habitats.

Shellfish, crustacea and small insects.

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Nesting site

Shelduck Tadorna tadorna


Summer: wet sand & mud (with green seaweeds), & dry-land (grassland); Winter: almost exclusively shallow coastal & estuarine waters with extensive low-tide areas of sand & mudflats & inland shallow waters near the coast

Invertebrates, molluscs (especially hydrobia) & worms, with smaller amounts of green seaweeds; insects & plant material (especially grasses & seeds) from dry-land habitats

On coastal marshes, farmland & other mainly open habitats close to feeding areas in burrows.

Teal Anas crecca


Widespread inland & coastal distribution in all seasons; Winter: frequent areas of shallow water on estuaries, coastal lagoons, coastal & inland marshes, flooded pasture & ponds

Mainly seeds of aquatic plants, chiefly Polygonum spp., Eleocharis & Ranunculus in freshwater, & Salicornia & Atriplex in seawater (especially in autumn & winter); plus various small invertebrates, principally Chironomid larvae & snails; some feed on winter stubble

Breed in dense cover, usually (but not always) near water, both far inland & near coasts

Turnstone Arenaria interpres

Wintering Migratory

Estuaries, sandy beaches, and particularly rocky shores.

Extremely varied diet, but the main food items in Britain are shrimps, winkles and barnacles.

Often with other wader species, on exposed rocks, saltmarshes and sand spits.

Wigeon Anas penelope

Wintering Migratory

Mudflats, saltings and flooded pastures

Eel grass, algae and grasses. Roost within 8 km of feeding site.

APPENDIX II

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APPENDIX III

81

APPENDIX IV

85

APPENDIX V

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