SEDIMENTOVERVÅKING 2014 Fogelberg pipeline · The Fogelberg field is situated at Haltenbanken, in...

SEDIMENTOVERVÅKING 2014

Fogelberg pipeline Centrica Energi

Report No.: 2014-1506, Rev. 02 Report No.: PP096432 Date: 2015-09-30

DNV GL – Report No. 2014-1506, Rev. 01 – www.dnvgl.com Page ii

Table of contents

1 EXECUTIVE SUMMARY ................................................................................................... 1

2 BACKGROUND .............................................................................................................. 2 2.1 Background on corals 4 2.2 Impact on corals from pipe laying operations 5

3 OBJECTIVES ................................................................................................................ 5

4 METHODS .................................................................................................................... 5 4.1 Sampling strategy 6 4.2 Video analysis 8

5 RESULTS ................................................................................................................... 11 5.1 Sediment characteristics 12 5.2 Fauna characteristics 12

6 IMPACT FROM PIPE LAYING .......................................................................................... 19

7 CONCLUSION ............................................................................................................. 21

8 REFERENCES.............................................................................................................. 22 Appendix A Registered megafauna Appendix B Running coral registrations

DNV GL – Report No. 2014-1506, Rev. 01 – www.dnvgl.com Page 1

1 EXECUTIVE SUMMARY Det Norske Veritas AS on behalf of Centrica has conducted a visual inspection of the pipeline route in connecting Fogelberg (PL477, block 640/12), and the Åsgard B template. The inspection took place in May of 2014 from the survey vessel Birkeland. The pipeline route was visually inspected using ROV in order to perform an assessment of the distribution of deep-water corals, sponge communities or other red listed fauna in the planned pipe laying routes. Results from the survey will be used in the planning of pipe laying operations.

Registered coral structures are presented in this report.

Main conclusions: - Lophelia pertusa structures were registered within the survey lines in ‘Excellent’, ‘Fair’ and ‘Poor’ health categories. - Other findings were comprised of single, scattered and common occurrences of the leather coral Paragorgia arborea with the presence of Primnoa resedaeformis. - As of now, survey tracks/planned pipe routes are placed in such a manner that pipe will be placed on top of registered coral structures or mounds and ridges consisting of reef formations.

- No red listed sponge species or high density soft bottom sponge communities were recorded.

The number of coral structures are given in Table 1-1 below.

Table 1-1 Total corals logged at Fogelberg pipe route

Nr. Lophelia Poor

Lophelia Fair

Lophelia Good

Lophelia Excellent

Paragorgia Single

Paragorgia Scattered

Paragorgia Common

Paragorgia High Density

Tot 1 4 2 29 15 3


2 BACKGROUND The Fogelberg field is situated at Haltenbanken, in an area where deepwater coral reefs are known to occur (Figure 2-1). The reef systems together with associated fauna can be considered vulnerable according to Norwegian red lists for species and for habitats and OSPAR lists of declining habitat types (Lindgaard et al. 2011, OSPAR, 2008-2009)

Figure 2-1 Location of the Fogelberg field in the Norwegian Sea.

According to the activities regulations for the oil and gas activities in Norway, extended baseline surveys are required in areas where sensitive seabed habitats can be expected.

The biodiversity in Norway is protected by the Nature Conservation Act (Naturmangfoldloven, NML). The purpose of NML is to preserve nature and its biological, landscape and geological diversity and ecological processes through sustainable use and conservation (§ 1). According to NML (§ 6), everybody shall act with care and do what is reasonable to avoid harm to the biodiversity. The Nature conservation act also implies a precautionary principle, i.e. that lack of knowledge should not lead to risk of serious irreversible damage to biodiversity.

There is a planned pipeline from Fogelberg to Åsgard B template, which is approximately 17000m long (Figure 2-2). The seabed along the proposed route was visually inspected by ROV and sonar by DNVGL. The goal of the surveys conducted was to describe the seabed fauna communities at each site, with special focus on possible existence vulnerable fauna types. The sonar detects coral structures and other obstacles with a detection distance potential up to 50 m on each side. All potential coral structures and other obstacles as seen on the sonar were inspected. There was a problem with the navigation file resulting in some missing positioning coordinates at the southern section of the pipeline route.


Figure 2-2 Map showing the ROV track along the proposed pipe laying route. Note the missing part in the southern section that was lost due to problems with position logging. Manual spot checks from the video were assessed and manually added to the log.


2.1 Background on corals Considerable knowledge on the corals at the Norwegian Continental Shelf has been assembled in

recent years, due to the possible impacts from offshore- and fishery industry on corals. Governmental measures such as the establishment of a monitoring program (MAREANO), protection of specified areas and regulations have been established. During 2010 Norsk olje og gass invited the international scientific community, authorities and industry to discuss contemporary knowledge regarding cold water corals and a possible way forward based on current knowledge and experiences. In June 2010 a workshop was organized in Stavanger with wide international and national participation, and 20th October 2010, a session on corals was part of the program during the “Forum for offshore environmental monitoring”.

In May 2012, the Directorate for Nature Management (DN, now merged with Norwegian Environment Agency) commissioned by the Ministry of Environment published a system for environmental valuation and vulnerability criteria for marine species and habitats (havmiljo.no). Both cold water corals and coral gardens are in general evaluated on three parameters; uniqueness, life historical importance, and sensitivity. As basis, Havmiljo.no refers to IMR (Institute of Marine Research) and OSPAR for evaluating these parameters. Lophelia pertusa and the gorgonian coral Paragorgia arborea are regarded as threatened and nearly threatened species according to categories defined by IUCN (International Union for Conservation of Nature) (OSPAR, 2008), and according to the Norwegian Red List for Species (Kålås et al., 2010), respectively. Other corals listed as nearly threatened in the Norwegian Red List are Anthelia borealis, Anthomastus grandiflorus and Swiftia pallida. All five species listed as nearly threatened should be prioritized for protection.

Furthermore, the Norwegian Red List for Ecosystems and Habitat Types 2011 (Lindgaard et al. 2011) rates the environmental status of ecosystems comprised of corals; e.g. coral reefs (stony corals mainly of the species L. pertusa) are listed as vulnerable, and coral gardens (predominantly comprised of Paragorgia arborea) are listed as near threatened. Coral gardens are defined in the OSPAR Agreement of 2008-7 as a relatively dense aggregation extending over at least 25m2 of colonies or individuals of one or more coral species, such as leather gorgonians (Gorgonacea), (Alcyonacea), sea pens (Pennatulacea), black corals (Antipatharia), hard corals (Scleractinia) and, in some places, stony hydroids (lace or hydrocorals: Stylasteridae).

Lophelia pertusa The cold water coral L. pertusa is the most common reef building stony coral in the North Atlantic Ocean, creating a diverse habitat for more than 1000 different species. L. pertusa is found on both sides of the Atlantic Ocean at depths from 30 meters down to 3000 meters, generally found at depths deeper than 300 meters. The largest Lophelia reefs in the world are found on the Norwegian Continental Shelf, covering an area up to of 60000 m2. L. pertusa is known for being relatively slow growing, and the largest reef structures are more than 9000 years old. In the recent years L. pertusa reefs have been recognized as a threatened habitat in need of protection. Paragorgia arborea: The gorgonian coral P. arborea, commonly termed bubblegum coral, is often found growing on or among L. pertusa reef structures. An individual fan-shaped Paragorgia is a colony of polyps connected by a central stem which typically branches off in one plane. Such colonies can grow up to about 6 meters high.

The reef building cold water coral Lophelia pertusa (white/grey), and gorgonian coral Paragorgia arborea (pink).


Deep water coral communities are generally regarded as sensitive to human activities. Sedimentation and covering of the live coral polyps is regarded as one of the major threats to living coral reefs from drilling (Mortensen, et al. 2001; White et al., 2005; Thiem et al., 2006; Kiriakoulakis et al., 2007; Davies et al., 2008). Criteria for adverse effects on corals caused by sedimentation of drilling discharges are not yet established, however, some conclusions may be made based on previous studies.

2.2 Impact on corals from pipe laying operations In general sedimentation and covering of the live coral polyps is regarded as one of the major threats to living coral reefs (Mortensen, et al. 2001; White et al., 2005; Thiem et al., 2006; Kiriakoulakis et al., 2007; Davies et al., 2008). Criteria for adverse effects on corals caused by sedimentation of drilling discharges are not yet established. However, the scientific programme “Coral Risk Assessment, Monitoring and Modelling” (CORAMM) has indicated that sedimentation in the order of 6.5 mm may cause adverse effect on Lophelia pertusa (Larsson and Purser, 2011). The endpoints in the study by Larsson and Purser (2011) were sediment coverage, coenosarc loss (=loss of skin), mortality and growth. The effect that they found at 6.5 mm exposure was that 50 % of the coral fragments had some degree of covered coensarc.

Amount of expected disturbances from any pipe laying operations will depend on the dimensions of pipelines to be placed out, methods and equipment that will be utilised and physical factors such as seabed sediment structure and seabed current systems. Generally speaking, impacts from the seabed by use of moored pipelaying vessels can have the potential of causing severe damage to the seabed communities. Conventional pipe laying operations utilise pipe laying barges that are moored to the seabed by use of a number of anchors connected via chains and fibre. The chains will move back and forth over the seabed as the barge progresses forward. These anchor chain movements across the seabed have the potential of doing substantial damage to seabed communities. Anchor operations will affect coral communities either directly by crushing due to the anchors, chains or grappling hooks, or indirectly by causing excessive sedimentation. By utilising dynamic positioning (DP) barges there will be no impact on the seabed from anchors. DP barges are strongly recommended when placing out pipes in environments with sensitive seabed habitats such as corals.

In most cases using DP vessels, the most important effects on seabed habitats are expected to come from trenching and rock dumping.

3 OBJECTIVES The scope of work was to visually inspect occurrences of sensitive or red listed fauna in the proposed pipe laying routes between Åsegard and Fogelberg fields. Findings in the video material were georeferenced and stored in a database/GIS system that is being developed for Centrica by DNVGL

4 METHODS Survey work was carried out by DNVGL between the 26.05.2014 and 27.05.14. The sea floor was surveyed using DNV’s observation class ROV- “Chimaera”. SPERRE SUB-fighter 15k (Figure 4-1) which was equipped with one high-definition video camera and two conventional resolution video cameras (zoom and wide-angle camera). An 8 megapixel still camera with flash was used for still photos. Simrad 9200 sonar on the ROV ensured identification of large objects within a radius of 50 m in the flight direction. A transponder (Kongsberg MST319) that communicated with the vessel’s HiPAP 500 transducer system was mounted on the ROV. Offset of data between HiPAP 500 and GPS were measured and included in the navigation application. With this system +/- ~ 5m accuracy in position and depth recording of ROV was obtained.In addition, two lasers with a spacing of 10 cm were used for calculating


object's sizes. Surveys were carried out from the combined fishing- and research vessel «M/S Birkeland» (Figure 4-1)

Figure 4-1 ROV type utilized during 2014 visual mapping survey (left) and M/S Birkeland (right, photo: Br. Birkeland AS).

4.1 Sampling strategy Fauna and seabed conditions were filmed and photographed during the whole lengtht of the survey track. Still images were taken regularly and usually with maximum 3-minute intervals. In addition, special observations were photographed. In total, 218 digital still images of the seabed were taken. The purpose of taking so many pictures was to form a good basis for species identification and analysis, while the video material gives a good overview of the relative amounts of different species.

Sonar data out to approx. 50 m radius from the ROV were recorded continuously during operation. Detours from the planned ROV-line were carried out to investigate special objects identified by the sonar.

A European standard for visual seabed surveys has been developed (NS-EN16260:2012). The standard gives valuable general guidelines for quality assurance, nomenclature to be used and technical requirements. DNVGL has adhered to these recommendations during the 2014 survey. Suggested requirements and methods for estimations of organisms are however not particularly adapted to estimating seabed sponge associations.

DNVGL uses ROV for visual mapping and recommend this over using drop camera, main differences between the two systems can be summarised as follows:


- Conventional drop cameras usually have a smaller field of view compared to a ROV camera; this can make it difficult to estimate abundances accurately.

- Drop cameras usually have up and down movement due to waves. ROV’s generally yield more stable video footage, and are very maneuverable. With drop cameras there is only limited control over the movement of the camera.

- Drop cameras usually have a field of view pointing straight down on the seabed, while ROV’s angle of the field of view usually is directed forward, along the seabed (Figure 4-2). Advantages with downward looking field of views are that sizes are the same all over the viewing frame. DNVGL ROV has both cameras facing forward and downwards, so that advantages from both systems can be utilized.

In addition to still camera, stills can be obtained from video by freezing the video frame so that abundances can be calculated. Video footage can by itself be regarded as still photos with a long dimension, as long as the observer is calculating or estimating exactly what is in each viewing frame (registering what is filmed when ROV moves over the area covered by the bottom of the screen to what was visible in top of screen).

Still camera footage usually has high resolution while video camera footage has lower resolution and can appear grainy. In general, hi-resolution still pictures provide a good basis for species identifications and calibration of abundance estimates, while video footage is more suitable for rapidly estimating densities and cover over larger areas.

Too high survey speed might lead to grainy or blurred photo and video material. This might lead to underestimation of sponge species that are hard to detect. A maximum survey speed of 0.5-1 knot is generally recommended (NS-EN 16260:2012).

Personnel experience and mindset can greatly affect density estimations at given points along the survey line. It is important that all personnel involved have undergone training in discriminating coverage of sponges on the seabed.

Figure 4-2 Barents Sea Sponge bed habitat and typical field of view when using ROV or drop camera.


4.2 Video analysis During the visual survey registrations were made of seabed sediment type, marks in the seabed, garbage and other seabed features. In addition, detailed registrations on seabed mega fauna were made. This included corals, sponges, invertebrates and fish. A modified Udden Wenthworth scale (according to NS9435) was used in the continuous categorization of the substrate along the seabed (Table 4-1).

All mega fauna species and habitat types encountered during the surveys were registered. In addition to species registration by review of the video material, the species lists are based on identification from still photos. Relative abundance of each species was given in following semi quantitative categories: “solitary/rare”, “scattered”, “common” and “high density”. A species list of all registrations is given in Appendix 1. In instances where fauna could not be identified to species, identifications were made to higher taxonomical levels, or “video species” were introduced in instances where the same type of unidentified fauna was encountered over several fields.

The video registrations of sponges were categorised into two groups; “soft bottom sponges” and “hard bottom sponges” (see Figure 4-5). Categorisation of sponge densities were made according to Figure 4-4.

An assessment of reef condition for the explored corals was made based on video documentation collected in the survey line. The scoring system/evaluation of condition is based on the DNV GL guideline developed for Norwegian Oil and Gas (DNV, 2013a). Corals are categorized as “poor”, “fair”, “good” and “excellent”. Examples of the categories for condition are shown in Table 4- 4-2 and Figure 4-5. Note that this coral reef condition is a way of giving values to the reef structures so they can be compared and does not necessarily describe the true health condition of the reef. Number of the non-reef building gorgonian coral Paragorgia arborea was registered in Semi-quantitative categories and number of individuals per 25 m2 was later counted, for OSPAR Coral Garden classification Figure 4-6. In the video analysis, each target surveyed has been demarcated with the outermost coordinates of the structure resulting in a polygon representing calculated area. Table 4-1: Sediment characterization according to the Udden-Wenthenworth scale, and categories utilized during the 2013 visual survey (ref. NS9435). Udden-Wenthworth scale Type of survey and main category Grain size Bottom substrate Screening Mapping/trend 0,6 µm – 3,9 µm Clay

Mud/sand Mud

3,9 µm – 63 µm Silt 0,063 mm – 2 mm Sand

Sand 2 mm – 4 mm Granules 4 mm – 64 mm Gravel

Boulder Gravel

6,4 cm – 25,6 cm Pebbles Pebbles 25,6 cm – 410 cm Boulder Boulder > 4 m Bedrock Bedrock Bedrock

Soft bottom sponges Hard bottom sponges

Figure 4-3: Categorization of main groups of sponges.


No sponge/ single specimen

(<~1% coverage)

0%

0.4%

Scattered

(~1- 5% coverage)

1.3% 4.8%

Common

(~5-10% coverage)

5.7% 7.4%

High

>~10% coverage

10% 18%

Figure 4-4: Density categories of soft bottom sponges.


Table 4- 4-2: Lophelia condition categories

Area of living Lophelia Coverage (%age of living corals)

Poor < 15 m2 0 – 20 %

Fair 15 – 50 m2 20 – 40 %

Good 50 – 100 m2 40 – 60 %

Excellent > 100 m2 > 60 %

<20% Coverage – Areas with primarily dead corals and some patches of living corals.

20-40% Coverage – Areas with high densities of dead corals and patches of living corals.

40-60% Coverage – Areas with high densities of living corals and patches of dead corals.

>60% Coverage – Areas with primarily living corals in high densities.

Figure 4-5: Examples of different percentages of living Lophelia coverage on coral walls.


Single refers to solitary Paragorgia corals (<5/25 m2).

Scattered refers to a distribution of Paragorgia corals spread out and in low numbers (5-10/25 m2).

Common – refers to areas with relatively frequent Paragorgia occurrences (10-15/25 m2)

High refers to dense aggregations of Paragorgia (>15/25 m2)

Figure 4-6: Examples of different categories of Paragorgia abundance.

5 RESULTS The seabed along the proposed line ranged from 253 to 332 m depth and was shallower towards the centre of the field. In total the field survey took approximately 19 hours to complete the visual mapping with a subsequent 218 photographs taken of the seas floor for habitat and species classification (Figure 5-1). The approximate distance of the area covered by the survey was 17000m. There was a survey positioning failure during a section of the southern end of the pipe inspection which resulted in the loss of positioning data. Manual spot checks of sediment and biology were assessed from recorded video and the acquired data was implemented into the final report.


5.1 Sediment characteristics The sediment registrations for the pipeline survey are shown in Figure 5-2. The seabed consisted mainly of mud/sand (97.3% of ROV loggings) with boulders and pebbles spread throughout. Boulders occurred at low densities on the seabed with 107 registrations (0.32%) Pebbles and stones accounted for the rest of the registrations and accounted for 2.15% of the ROV registrations.

5.2 Fauna characteristics General registrations of fauna are presented in Figure 5-4. Seabed fauna was generally distributed scattered throughout the survey line with higher density of organisms and species around rocks and harder substrates, and particularly around the reef systems where there were elevated amounts of niches and hiding places for various organisms. Species numbers were recorded as relatively low on the field. Species list of mega fauna registered during the survey is presented in Appendix A, in total 21 species of mega fauna were registered at the seabed. Coral and cnidarian findings of significance comprised of Lophelia pertusa, Paragorgia arborea, Primnoa resedaeformis and Cerianthus spp.

Sponges occurred as single and scattered densities along the survey line. The sponges registered were predominately hard bottom sponge species in, registered along 43.4% of the sea floor (Figure 5-4). On the small rocks were scattered occurrences of hard bottom sponges such as Phakellia ventilabrum and Phakellia sp., Hymedesmia sp., and Mycale lingua. On the softer sediments were moderate abundances of Stylocordyla borealis. No red listed sponge species or high density soft bottom sponge communities were recorded.

All coral registrations are given in Figure 5-5. The red listed species Lophelia pertusa were recorded along the pipeline route. Lophelia was registered in categories of ‘Excellent’ ‘Good’, ‘Fair’ and ‘Poor’ in regards to health categorization. The two occurrences of Lophelia in Excellent condition were located at approximately 394258 E, 72361595 N and 394419 E, 7235478 N (ED50 UTM32N) shown in Figure 5-6. Other findings were comprised of single, scattered and common occurrences of the leather coral Paragorgia arborea as well as the presence of Primnoa resedaeformis. The overview of coral registrations are shown in Table 5-1.


Figure 5-1 Survey track and photograph registrations of the proposed pipeline route at Fogelberg, 2014.


Figure 5-2 Sediment registrations at Fogelberg. Relative amounts of seabed categorized into different substrate types are given in the pie chart.


Figure 5-3: Example images seabed fauna registered at Fogelberg. a) Sebastes spp, b) Paragorgia arborea and Primnoa resedaeformis on dead Lophelia reef, c) Pebbles with hard bottom sponges including Phakellia ventilabrum, d) Lophelia pertusa with Paragorgia aborea, e) sea cucumber Parastichopus tremulus, f) rocks covered by Hymedesmia sponges and Mycale.


Figure 5-4 Registrations of sponges and other noteworthy fauna at Fogelberg. Relative amounts of seabed classified into semi quantitative cover estimates are given in pie chart.


Figure 5-5 Registrations of Lophelia and Paragorgia corals along the proposed pipeline route at Fogelberg


Figure 5-6 Registrations of Lophelia pertusa in ‘Excellent’ condition in relation to other corals found along the proposed pipeline route at Fogelberg. Line segment shown is from the northern part of thetransect.

Table 5-1 Total corals logged at Fogelberg pipe route

Nr. Lophelia Poor

Lophelia Fair

Lophelia Good

Lophelia Excellent

Paragorgia Single

Paragorgia Scattered

Paragorgia Common

Paragorgia High Density

Tot 1 4 2 29 15 3


6 IMPACT FROM PIPE LAYING DNV GL has no detailed information on the planned pipe laying operations at Fogelberg. Amount of expected disturbances from any pipe laying operations will depend on the dimensions of pipelines to be placed out, methods and equipment that will be utilised and physical factors such as seabed sediment structure and seabed current systems. A general presentation of methods used is shown in Figure 6-1. Generally speaking, impacts from the seabed by use of moored pipelaying vessels can have the potential of causing severe damage to the seabed communities. Usually in offshore operations in Norway utilising DP rig (dynamic positioning), the most important effects on the seabed can be expected to come from:

- trenching

- rock dumping

The most important source of impact on the seabed fauna at Fogelberg is generally expected to be direct removal of seabed communities, crushing of coral structures and disturbances due to sedimentation and smothering.

a) b)

c) Figure 6-1: Summary of probable sources for disturbances from pipe laying. a) Illustration showing methods for trenching, here a jetting sledge (Gowen et. al., 1980); b) rock dumping at seabed by pipe fall method; c) causes for disturbance in the vicinity of pipelines (Rambøll, 2008).


According to Dicks (1982) disturbances to the fauna can be expected in a 15 meter wide belt around the pipeline. DNV GL (2013a) recommends placing pipelines more than 50 meters away from corals. If this cannot feasibly be met, then engineering restrictions should apply to the pipe laying operations (e.g. as shown in Table 6-2). In general terms, for many pipelaying operations, the risk of seabed communities is expected be as shown in Table 6-1. The distances shown here are only meant as reference and should not be used at Fogelberg without further assessments of risk arising from planned operations at Fogelberg pipe route.

Table 6-1 Example of probability distances for assessing impact/risk to coral communities from pipelaying.

The visual survey conducted by DNV GL resulted in the discovery of three coral habitats which are within the high impact zone according to Table 6-1 (areas to the north of the visual survey route). The coral targets, consisted of ‘Excellent’ Lophelia pertusa and/or ‘Common’ Paragorgia aborea and are all found right on the proposed corridor. To prevent damage on corals the proposed pipeline route must be changed, as no mitigation measures can prevent coral damage (Figure 6-2).

Figure 6-2 Maps showing coral targets at Fogelberg pipeline route within high probability of impact from the pipe laying operations. Buffer zones are shown for reference only and needs to be adjusted according to actual pipe laying plans at Fogelberg.


Table 6-2: Example of engineering restrictions that can be applied during planning of pipe laying routes.

7 CONCLUSION There are occurrences of red listed species Lophelia pertusa as well as gorgonian corals within the proposed pipeline route. Of particular interest are the occurrences of Lophelia pertusa in ‘Excellent’ condition, situated in two areas located at 394258 E, 72361595 N and 394419 E, 7235478 N, as well as the Paragorgia aborea registered in ‘common’ densities located approximately at the three locations 395650 E, 7230248 N; 394417 E, 7235475 N and 394255 E, 7236201 N (ED50 UTM32N). The corals are situated across the proposed pipe laying corridor and would be harmed by the pipeline as they are currently routed. DNV GL proposes that an alternate pipeline route circumventing the coral targets be implemented in order to avoid harm to the corals.


8 REFERENCES

Davies, A.J., Wisshak, M., Orr, J.C., and Murray Roberts, J., 2008. Predicting suitable habitat for the

cold-water coral Lophelia pertusa (Scleratinia). Deep-Sea Research I, 55, 1048-1062.

DNV. 2013b. Mapping and environmental impact assessment of sponge communities in pipe laying routes at Snøhvit field.

DNV, 2013a. Guideline. Monitoring of drilling activities in areas with presence of cold water corals. Report nr: 2012-1691, 2013-01-15, Rev 01.

Gowen AM, Goetz MJ, Waitzman IM. 1980. Choosing offshore pipeline routes. Problems and soultions.EPA. Interagency Energy/ Environment R&D Program Report. EPA 600/7-80-114. Kiriakoulakis, K., Freiwald, A., Fisher, E., Wolff, G.A., 2007. Organic matter quality and supply to

deepwater coral/mound systems of the NW European Continental Margin. International Journal of

Earth Sciences, 96 (1), 159–170.

Larsson & Purser, 2011. Sedimentation on the cold-water coral Lophelia pertusa: Cleaning efficiency

from natural sediments and drill cuttings. Marine Pollution Bulletin 62 (2011) 1159-1168.

Lindegaard, A and Henriksen, S (eds) 2011. The 2011 Norwegian Red List for Ecosystems and Habitat Types. Norwegian Biodiversity Information Centre, Trondheim. Mortensen, P.B., Hovland, M.T., Fosså, J.H., and Furevik, D.M., 2001. Distribution, abundance and size of Lophelia pertusa coral reefs in mid-Norway in relation to seabed characteristics. Journal of the Marine Biological Association of the United Kingdom, 81, 581-597. Norsk Standard. 2009. NS9435, Vannundersøkelse, Visuelle bunnundersøkelser med fjernstyrte og tauete observasjonsfarkoster for innsamling av miljødata. Under utarbeiding OSPAR, 2008. OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic. OSPAR List of Threatened and/or Declining Species and Habitats (Reference Number: 2008-6, Replaces agreement 2004-6). OSPAR, 2009. OSPAR Recommendation 2010/9 on furthering the protection and restoration of coral gardens in the OSPAR Maritime Area Rambøll. 2008. Nord Stream AG. Offshore pipeline through the Baltic Sea. Spreading of sediment and contaminants during works in the seabed Rambøll Memo 4.3A-5 Thiem, Ø., Ravagnan, E., Fossa , J.H., Berntsen, J., 2006. Food supply mechanisms for cold-water corals along a continental shelf edge. Journal of Marine Systems 26, 1481–1495. White, M., Mohn, C., de Stigter, H., Mottram, G., 2005. Deep-water coral development as a function of hydrodynamics and surface productivity around the submarine banks of the Rockall Trough, NE Atlantic. In: Freiwald, A., Roberts, J.M. (Eds.), Cold-Water Corals and Ecosystems. Springer, Berlin/Heidelberg, pp. 503–514.

DNV GL – Report No. 2014-1506, Rev. 02 – www.dnvgl.com A-1

APPENDIX A Registered megafauna Each species observed is given an overall abundance rank, categorised as “High” (3), “Moderate” (2), and “Low” (1)

Species Relative Abundance

Actinostola callosa 1

Bonellia viridis 1

Brosme brosme 1

Buccinum spp. 1

Ceramaster granularis 1

Echinus acutus 1

Gadus morhua 2

Henricia spp. 1

Hymedesmia spp 2

Melanogrammus aeglefinus 1

Munida spp. 2

Mycale lingua 2

Parastichopus tremulus 2

Phakellia sp. 3

Phakellia ventilabrum 2

Pleuronectiformes indet. 1

Pollachius virens 3

Protanthea simplex 1

Rossia sp. 1

Solaster endeca 1

Stylocordyla borealis 2

DNV GL – Report No. 2014-1506, Rev. 02 – www.dnvgl.com B-1

APPENDIX B Running coral registrations

Table 1: Running coral registrations in the survey track for pipe laying route between Åseberg and Fogelberg. Positions in ED50 UTM32N

Event Name Easting Northing

Paragorgia‐ Single 396462,7 7223607

Paragorgia ‐ Scattered 396465,3 7223602





Paragorgia ‐ Scattered 396466 7223603















Paragorgia ‐ Scattered

Lophelia‐dead


Paragorgia‐ Single






Lophelia‐dead









Lophelia‐dead










Paragorgia‐ Single 395668 7230202

Lophelia‐dead 395622,6 7230209


Lophelia‐dead 395623 7230209






Lophelia‐Poor 395620,2 7230211


Lophelia‐Poor 395620 7230212







































Paragorgia ‐ Common 395642,1 7230245


Paragorgia ‐ Common 395644 7230244






























Lophelia‐Good 394422,1 7235472


Lophelia‐Good 394422 7235473
























































































Lophelia‐Moderate 394445,7 7235500


Lophelia‐Moderate 394446 7235499






















































































Paragorgia‐ Single 396428 7223421




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