Po river , Po river delta and Sacca di Goro lagoonPierluigi Viaroli & Gianmarco GiordaniDepartment of Environmental Sciences, University of Parma di ParmaJosé M. ZaldivarJRC-EC, IspraChiara MocenniCenter for Complex System Studies, University of SienaSilvano BencivelliEnvironmental Office, Province of Ferrara

The Po rivermain features and environmental issues

Po river watershed

Sacca di Goro

Urbanisation in the Po river catchment as measured with the light emission at night (mean annual emission)

Light blue = no light emissionBlack = high-intensity light emission in both 1992 and 2000 Red = light intensity increased from 1992 to 2000Yellow = new light source in 2000

NOAA-NESDIS National Geophysical Data Center, Boulder,

Colorado,USA

Human population = ~ 16,500,000Pig population = ~ 5,000,000Cattle population = ~ 4,000,00035 % of the National Agriculture Production55% of the National Animal Production37% of the National Industrial Production

Po River – Mean Annual Discharge1961-1990 = 46 *109 m3 2003-2007 = 29-35 *109 m3

Po River watershed – annual water demand agriculture = 16.5 *109 m3 industry = 1.5 *109 m3 municipal = 2.5 *109 m3

Data source G. Bortone, Regione Emilia RomagnaPo River Basin Authority

Anno

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75

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AnnoC

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160

19

73

-19

75

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87

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99

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Dissolved inorganic (violet) and total (red) phosphorus loadings delivered from the Po river to the Adriatic Sea 1968-1993: Provini et al., 1992; Provini & Binelli, 20061999 -2007: Viaroli et al, 2008

Nitrate loadings delivered from the Po river to the Adriatic Sea 1968-1993: Provini et al., 1992; Provini & Binelli, 20061999 -2007: Viaroli et al, 2008

P and N loadings eutrophication of Adriatic Sea

4100

2050

0

m3/

sec

1/1/91 5/6/93 8/11/95 12/4/98 14/9/00 17/2/03 22/7/05 25/12/07data

River discharge - Change Point Analisys of daily river discharge of the Po River from 1991 to 2007. The blue boxes represent time periods with water discharges that are statistically different.See also Zanchettin et al., 2008, who analysed the Po river flows from the last two centuries

Viaroli et al., 2008. P and N loadings under altered hydrological conditions in the Po River. A project funded by the Po River Basin Authority (2007-2008). Final Project Report

Po river: number of days with water discharge< 500 m3 s-1 (line) and < 250 m3 s-1 (bar)

year

num

ber

of d

ays

P. Viaroli et al., 2008. P and N loadings under altered hydrological conditions in the Po River. A project funded by the Po River Basin Authority (2007-2008). Final Project Report

SALINE WEDGE IN THE PO RIVER DELTA

With water discharge < 250 m3 s-1 the saline wedge reaches up to 25 km upstream

30 June 2003

km upstream

Salinity 20 psu

(bottom water)

Relationship between saline wedge (km upstream) and river discharge (mean of the five days before) in the Po di Goro River from July 2003 to April 2007 (data from Provincia di Ferrara, Unità Acque Costiere e Pesca and ARPA - Regione Emilia Romagna)

Viaroli et al., 2008. P and N loadings under altered hydrological conditions in the Po River. A project funded by the Po River Basin Authority (2007-2008). Final Project Report

Daily load of Total Phosphorus

Days since January 1st, 2003

1/03

4/03

7/03

10/0

3

1/04

4/04

7/04

10/0

4

1/05

4/05

7/05

10/0

5

1/06

4/06

7/06

10/0

6

1/07

4/07

7/07

10/0

7

t P d

-1

0

100

200

300

4002003 2004 2005 2006 2007

flood events

Effects of altered hydrology on P loading (flash loads?)

Viaroli et al., 2008. P and N loadings under altered hydrological conditions in the Po River. A project funded by the Po River Basin Authority (2007-2008). Final Project Report

19/09/07

POP53%

exch-PO4 21%

PO4~Fe10%

PO4~Ca auth. 13%

PO4~Ca detr.3%

26/11/07

POP60%

PO4~Fe5%

exch-PO4 6%

PO4~Ca auth. 22%

PO4~Ca detr.7%

19 september 2007

Non flood

26 November 2007

Flood

River discharge (m3 s-1) 725 3419

Suspended Particulate Matter (mg L-1) 102.5±11.9 1339.6±252.6

Total Particulate Phosphorus (µg P L-1) 164 1140

Exchangeable PO4 (µg P L-1) 34.3±1.6 65.8±4.5

Iron bound (µg P L-1) 16.3±5.4 59.7±3.6

PO4-Ca authigenic (µg P L-1) 22.1±2.2 247.1±76.7

PO4-Ca detritic (µg P L-1) 4.2±2.5 80.1±10.9

Particulate Organic P (POP) (µg L-1) 89.1 687.3

P loading from flood events is not readily available to primary producers

Daily load of Total Nitrogen

Days since January 1st, 2003

1/03

4/03

7/03

10/0

3

1/04

4/04

7/04

10/0

4

1/05

4/05

7/05

10/0

5

1/06

4/06

7/06

10/0

6

1/07

4/07

7/07

10/0

7

t N d

-1

0

500

1000

1500

2000

25002003 2004 2005 2006 2007

flood events

Less than 15% of the total N loading is delivered by flood events

The Sacca di Goro lagoonFeatures and threats

•Eutrophication of the Ebro, Po and Rhone deltas (1989-91)•CLEAN: coastal lagoons and anaerobic processes (1993-94)•NICE: nitrogen cycling in estuaries (1996-98)•ROBUST: the role of buffering capacity in stablising coastal lagoon ecosystems (1996-98)•DITTY: development of an Information Technology Tool for the Management of European Southern Lagoons under the influence of river-basin runoff (2003-06)•3 national relevant projects (PRIN 1998-2004)•Projects funded by province, region and ministry of agriculture and fishery

Sacca di Goro (Po river delta, Italy)

Adriatic Sea

Sacca di Goro

Valli di Comacchio

Valle Smarlacca

Adriatic Sea

Sacca di Goro

Valli di Comacchio

Valle

Smarlacca

Valle Bertuzzi

AgricultureAquacultureUrbanisationIndustry

Eutrophication Contamination(chemical+microbial)

Clam quantity and quality

Agriculture crops

Anoxia Mollusc kill

Meteo and climate changes

Clam marketingAgr marketingTourism revenue

Policies and decision:canal dredgingbarrier cut

Sacca di Goro lagoon

Previous applications of the DPSIR scheme

Aquaculture

•Enlarge•Constant•Restrict ?

Clam production

Environmental quality

Oxygen

SPM demand

Climate change River discharge

Natural park

Actions

Canal dredging

Littoral barrier cut

Bottom nourishment

Local economy

e.g. employers

Out of control?

PV

GI

CB

PG

Po River Delta

Po River

PH

Comacchio lagoon

SG

AB

Po di Volano – Sacca di Goro Watershed

1991 2001 difference

human population 72114 67086 -7,0

animal cattles 10158 2502 -75,4rearing pigs 8546 14023 64,1(units) poultry 930588 326451 -64,9

agriculture cereals 26869 27864 3,7grasses 2333 2701 15,8

(surface in vegetables 5349 3565 -33,4hectares) permanent crops4483 3465 -22,7

industrial 10778 12234 13,5other 4540 3535 -22,1

Po di Volano watershed - Land use changes from 1991 to 2001 (ISTAT census data). Surface data considered here accounts for approximately 90% of the total surface area

1991 2001 1991 2001human population 316 294 63 59animal rearing 1100 452 367 152agriculture 747 747 26 26atmosphere 594 594 0 0total loading 2757 2088 456 237

-24% -48%background of the Po River ????

Potential loadings (tons/year) that are generated by different activities in the Po di Volano watershed:

•Data from ISTAT census 1991 and 1992 transformed with IRSA-CNR coefficients (Barbiero et al., 1991 and 2000)

•Atmospheric loadings have been obtained from rain chemistry data (RIDEP, 1991-93)

Sacca di Goro

aquaculture development

the catch fishery is declining

sea-food poduction is moving in the near-shore and/or in lagoonsCrossland, C.J., Kremer, H.H., Lindeboom, H.J., Marshall Crossland, J.I., Le Tissier, M.D.A., 2005. Coastal Fluxes in the Anthropocene. The Land-Ocean Interactions in the Coastal Zone. Project of the International Geosphere-Biosphere Programme. Global Change - The IGBP Series n° XX . Springer, 232 p.

Produzione di vongole nella Sacca di Goro

0

2.000

4.000

6.000

8.000

10.000

12.000

14.000

16.000

18.000

20.000

1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

ton

nellate

Annual clam production (t yr-1) in the Sacca di Goro lagoon

Employers: ca. 1,600 total annual revenue: up to 100 M€

Clam farming in Sacca di Goro lagoon

Actual extension of the clams farming concessions: 13.0 km2

Not completely exploited

Impact of mussel and clam farming on sediment

Mussels: Only organic enrichment

Clams: Organic enrichment and sediment reworking

Winter Summer

kg fw

m-2

0

10

20

30

40

50ControlClamsMussels

Typical biomass under farming conditions – harvesting in late spring (Northern Adriatic lagoons)

Sediment carbon oxidation and oxygen consumption rates

Winter Summer

mm

ol C

O2

m-2

h-1

0

5

10

15

20

25

Winter Summer

mm

ol O

2 m

-2 h

-1

-25

-20

-15

-10

-5

0

ControlClamsMussels

Carbon oxidation Oxygen consumption

Sediments sulphate reduction rates

Winter Summer

mm

ol S

RR

m-2

h-1

0

1

2

3

4

5

ControlClamsMussels

Clam farming contributes to benthic metabolism modificationsrespiration as a function of clam biomass

biomassa (g molluschi secchi m-2)

0 100 200 300 400 500 600 700

mm

ol m

-2 h

-1

-30

-20

-10

0

10

20

30

y=1.35+0.03x

r2=0.84

y=-2.97-0.03x

r2=0.98

CO2 O2

x: clam biomass (g dw m-2)

y: m

mol

m-2

h-1

Clam farms cover 8 km2. At 20 °C, with an average biomass of 200 g.m-2 oxygen demand is –8.97 mmol m-2 h-1. The background (sediment only ) is -2.97 mmol m-2 h-1. In summer, at the lagoon scale, clams account for an increase of about 38% of oxygen demand (modified from Bartoli et al., 2001)

Clam harvesting impacts on sediment quality and fluxes

                                 .                                 .

x 102 =

Pre-H H Post-H

Oxygen -3.05±2.39 *- 60.90±8.91 -5.78±1.16

Ammonium 0.22±0.30 *11.40±2.31 0.10±0.23

Nitrate 0.13±0.23 -0.25±1.10 0.21±0.74

SRP -0.017±0.068 *1.04±0.48 -0.019±0.056

DRSi 0.76±0.17 *11.90±0.74 -0.31±0.29

Sediment dredging for clam harvesting induces changes of resuspension and benthic fluxes. Experiments with core incubation were performed to simulate the effects of clam harvesting. Fluxes were determined with conventional incubation techniques (units: mmol m-2 h-1)

Pre-H: before harvesting, H: during harvesting, Post-H: 8 hours after harvesting has ceased.

Main environmental issues:Macroalgal blooms, anoxia and dystrophic crises

18 June 1991

5 May 1992

7 June 1994 27 May 1997

Ulva rigida Gracilaria verrucosa

Macroalgal coverage in the Sacca di Goro lagoon

Sacca di Goro lagoon (Italy): macroalgae distribution on 12 May 2008. Mixed stands of Ulva and Gracilaria

3 2 8 52 9 2 02 5 5 52 1 9 01 8 2 51 4 6 01 0 9 57 3 03 6 500

200

400

600

800

1000

1200

1989 1990 1991 1992 1993 1994 1995 1996 1997

biomass (g DW m )A-2

328529202555219018251460109573036500

50

100

150

200

250

1989 1990 1991 1992 1993 1994 1995 1996 1997

dissolved oxygen (% saturation) A

Sacca di Goro lagoon (Po River Delta,

Northern Adriatic Sea)

biomass of the seaweed Ulva rigida

and related dissolved oxygen concentrations

Transition from macroalgal blooms to dystrophic crises (Sacca di Goro 1992)

Conflicting issues

Further development of clam farming - Requested concessions

Total surface area requested for new concessions: 8.2 km2

Acceptable by the Ferrara Province :+ 10% (1.3 km2)

Maximum sustainable:+30% (3.9 km2)

Two possible locations:-Inner part (inside the lagoon)-Seaside (outside the lagoon)

Agriculture

The watershed of the Sacca di Goro is exploited for agriculture (80% of the total surface, 650 km2).

A. Wheat, corn, sugar beet (extensive crops) grown with conventional techniques. High input of pesticide and fertilizers.

B. Rice grown in paddy soils with permanent submersion and needs pesticides and fertilisers. The permanent flooding keeps pesticides and fertilisers in solution and increases the risk of pollution of the lagoon.

C. Vegetables (intensive crops) are grown with conventional techniques. The impact is maximum in green houses.

D. Vegetable are grown wit organic practices, impacts are lower.

The development of different alternatives can lead to a different risk for the lagoon with

B>AC (conventional)>>D(organic)

Regional Park of the Po River Delta

The eastern part of the watershed and of the lagoon belong to the Regional park of the Po River Delta, that is going to be transformed into a National Park. It is a Ramsar site and UNESCO natural heritage under constraints for natural resources and ecosystem exploitation.

In the long term, this can potentially cause a conflict with the fisherman companies.

The natural landscape of the Po Delta has a valuable potential for recreation and tourism. The conventional tourism could be integrated with eco-tourism, that potentially covers also autumn and winter periods that are suitable for bird-watching and other naturalistic purposes Tourism facilities are located along the coast in the same district and basically serve for summer holidays.

Park of the Po River Delta

Climate changes (IPCC, 2001)

2020•1.5 ºC increase in mean summer temperature •No change in mean precipitation values, but an increase of 14% in its variability

2050•2.4 ºC increase in mean summer temperature •No change in mean precipitation values, but an increase of 24% in its variability

2080•3.3 ºC increase in mean summer temperature•No change in mean precipitation values, but an increase of 32% in its variability

 

Increase of water temperature and its duration

effects on clam metabolism and recruitment

increase of pathogen diffusion

risk of harmful microalgal blooms

increase of oxygen demand and sulphide production

biological invasion by exotic species

 

Increase of flooding (autumn 2000):

submersion in the depressed areas

decrease of salinity in the lagoon, that is dangerous for clams

Discharge of SPM which is beneficial for clams

Increase of drought (summer 2003):

decrease in freshwater discharge.

On the land side, it could cause an increase of costs (e.g., for irrigation) and decrease in vegetal production, as in 2003.

On the lagoon side, less freshwater discharge could cause a decrease in phytoplankton production and biomass with

effects on clam and mussel crops

Scenarios from the IPCC Assessment Report 2007

Major pressures

Coastal impacts

Pressure status

Trends

Urbanisation Eutrophication

Pollution

(waste/sewage)

High

Seasonal tourism

River damming and regulation

Water abstraction

Altered hydrology

(reduced water flow, erosion, flloding, flash floods)

Medium

Locally high

Agriculture Eutrophication Pollution

Medium

Locally high

Industrialisation

Mining/dredging

Pollution Medium

Locally high

Synthesis and typology of the river catchment-coast interactions (modified from Crossland et al, 2005. Coastal Fluxes in the Anthropcene. Global Change-The IGBP Series. Springer, Berlin; Aliaume et al., 2007. Coastal lagoons in southern Europe: Recent changes and future scenarios. Transitional Water Monographs, 1: 1-12)

DITTY PROJECT - fish farmersPoint of view of stakeholders and end users (environmental side)

Priorities for fishermen and local administrations• Productivity of the lagoon (clams)• Access to the exploitation of lagoon resources

Conditions for having an high productivity• Freshawater inputs with high energy (SPM) and nutrient contents• Hydrodinamics: high• Water depth: > 1 m• Sediment quality

Actions which have an high priority level• Canal dredging hydrodynamics, water depth• Bottom nourishment sediment quality• Removal of faecal materials (sediment arrowing) sediment quality• Management of littoral sand barrier and littoral arrows hydrodynamics and siltation• Identification of exploitation threesholds

Factors that can generate conflicts• Activities in the watershed • Po River Delta Natural Park

Factors out of control• Climatic changes • Invasive and toxin producing species  

 

DITTY PROJECTPoint of view of stakeholders and end users (socio-economic side)

The local economy depends upon production potential of the lagoon

The lagoon and the watershed - lagoon interactions are highly dynamic

Lagoon management needs

•know-how capacity

•financial support

•laws and rules

Production management needs

• management of the natural stock (nursery and farming areas)

• management of quality and marketing performances (e.g., quality certification, product tracking, etc.).

•common and shared strategies

•equity in the distribution of the licensed areas (employers/licensed areas=constant)

• laws and rules

Overall, there is a need of lagoon planning.

With a good planning, the Po River Delta Park has to be considered as an additional value

Integrating knowledge and policies

Integrated River Basin Management (IRBM)

Integrated Coastal Zone Management (ICZM)

Integrated Coastal Area and River Basin Management (ICARM)(http://www.encora.eu)

IRBM ICZM ICARM

1.PHYT

R50

F04 F40

F15F58

F35

F43

F25

F24

F10 F01

F54

F14 4.SESTON

6.DN2.ULVA

5.SEDIM

3.TAPES

F13

F20

F36F30

F03

F45

F61

F46

F60

F06

F62

F56F50F65

Tool box: loop and network analysis, food web analysis

Sea

Sys 1 Sys2

sea

Sys 1

Sys2

2 boxes model

2 layers model

LOICZ BM - Budgets

 To assess the sustainability of the mollusk shellfish production one has to analyse simultaneously coastal water fluid-dynamics, river runoff influence, ecology, nutrients cycles, macro-algal blooms, bacterial contamination, as well as the economical implications of different scenarios.

Watershed Model

Coastal Lagoon Model

FlowsNutrientsContaminants

Agriculture/farms

Inhabitants (WWTP)

Meteo. dataClimate Change

Industry

Meteo. dataClimate Change

Aquaculture

Open Sea: Flows,Nutrients, Contaminants

ManagementOptions

e.g. channel dredging

e.g. concessions

e.g. tertiary treatment

e.g. subsidies

e.g. pollution taxes

Tool box: Models as Quantification ToolsTool box: Models as Quantification Tools

Tool box: Decision Support System Tool box: Decision Support System

SystemModel

ScenarioGeneration

EnvironmentalAnalysis

Socio-economicAnalysis

Indicators ofSocio-economicsustainability

Input data

Input data

Env. output data

Scenarioparameters

Exogenous inputs

ModeledVariables

Ecological indicators

Sustainabilitytest

Global indicators

No Scenariorejected

Resourceallocation

Yes

Decisions