NEEI and Natura 2000 Workshop Brussels – Sept 17 2008

1. Effects of Extraction of marine sediments on the marine environment; current international best practice Gerry Sutton Deputy Director Coastal and Marine Resources Centre University College Cork NEEI and Natura 2000 Workshop Brussels – Sept 17 2008

2. Topics • Overview of dredging process • Main Impacts of MA Extraction • Risk Management Frameworks • Guidance – Initial Feedback • Wider Initiatives / Progression

3. Typical (5-8k tonne) trailer hopper suction dredger, drag head raised. Photo courtesy of BMAPA

4. Typical (5-8k tonne) trailer hopper suction dredger in action. Photo courtesy of BMAPA

7. Effects of the dredging process • Negative environmental impacts • Seabed and associated biota • Fisheries • Coastlines • Conflicts with other users • Sustainability ??? • Production/investment costs ? • Highly dependant on interplay of macro/micro economic factors- • Dependant on nature of material • Additional processing-washing de-wooding • Few appropriate/holistic cost-benefit analysis-models (Symonds 2002, Moreton Bay Study)

8. Marine Ecosystem A Complex of Trophic Levels & Food Webs– Driven by Hydrodynamic / Geophysical and Climatic Forces Two main compartments • Benthic (Seabed) • Pelagic (Water Column)

9. Aggregates Extraction - Impacts Impacts Mainly Site Specific • Removal of Substrate and Alteration of the Physical Nature of the Sea Bed • Removal and Damage to Benthic Community (reduction in species diversity , abundance and biomass) • Impacts on Fisheries (?) (potential impacts on shellfisheries and herring spawning most reported)

10. Aggregates Extraction - Impacts Gravel Progressive increase in sand content particularly with on-board screening – may lead to instability in seabed and delayed recovery for many years Sand Recovery is believed to be faster than at gravel sites depending on local hydrodynamics – exceptions

11. Mode Effect Perceived Impact Suspension Reduced light penetration Reduced algal growth; reduced visibility; reduced primary productivity Increased suspended solids Visual impact; decreased respiratory capacity, decreased reproductive capacity; decreased feeding capacity; deterrence of spawning, modification of migration routes Increased nutrient flux Increased feeding opportunity; increased reproduction rates Settlement Increased sedimentation rates Smothering of slow moving bottom dwellers; blocking of filter feeders; smothering of seabed fauna; smothering of hard bottom communities; silting of crab and lobster holes. Changes in sediment type Alteration of seabed sediment particle size distribution; alteration of character of sediment supply to beaches New sediment regimes Smothering of archaeological sites Summary of the impact of plumes generated by aggregate dredging operations. Source: Hitchcock et al., (1999).

12. Aggregates Extraction - Impacts Impacts greatest in the dredge zone (but may extend 1km+) Impacts greater at sites with on-board screening Impacts greater and recovery slower at intensively dredged sites (with or without on-board screening)

13. Aggregates Extraction - Impacts IMPACTS ON FISHERIES RESOURCES Comparatively very little research on the direct and indirect impacts of aggregates extraction on fisheries resources has been undertaken (or are only publishes in ‘grey literature’) Studies to date rarely provide clear-cut evidence of impacts However, a precautionary approach dictates that certain locations the likelihood of adverse fisheries impacts are to be expected and should be avoided or mitigated

14. Trends/priorities in Environmental Research • Past research-emphasis recolonisation, and the primary biological and physical impacts of dredging at the point of extraction. • More recent attention geared to acquiring better understanding of: • a) secondary effects i.e. dispersion of dredge plume sediments, resuspension of fines and their transport out of the dredge area • b) strategic cumulative (and in combination) effects of multiple dredging operations within limited areas • c) consistency in REA, SEA, IEA and Risk Assessment • d) strategies-marine spatial planning and the ecosystem approach • e) monitoring techniques

15. Guidance-Initial Comments/Questions • Mechanisms to improve consistency and compliance wrt Natura 2000 designation processes and monitoring regimes (clarity of definitions e.g wrt reefs etc) • Clarity on Scope - What level of detail in proposed guidance- • spatially explicit (zonation)? • large variation between states consenting regimes • allocation of risk/cost between state and developer • Integration with other human activities in context of MSP/ICZM initiatives • Lack of consistent baseline information on marine environment • Need to define “important” e.g. if extraction to be excluded • Need to explore positive potentials e.g. constructive dredging, CO2 saving

16. Managing Risk • Still immature for MA’s- Partial or comparative • High uncertainties-low resolution-banding (H,L,M) • Need thresholds/limits for spp and environments • UK • CEFAS Stardised protocols for fish impact assessment • MARA (2006) • Consistent framework Source-Pathway-Receptor-Consequence’ or ‘S-P-R-C’ model • More transparent, objective creates audit trail in decision making process • Software/GIS tools? • PEC/PNEC approach • PEC = Predicted Environmental Concentration; • PNEC = Predicted No Effect Concentration.

17. Immediate Sources/Relevant Case Studies • ICES Guidelines • Oresund Link Project • UK Marine SAC’s project (2001) • Posford Duvivier and CCW • Good review and synthesis of research, e.g impacts • Guidance on impacts Annex 1 and Annex 11 • Cumulative impacts and guidance on CEIA • Monitoring • SAC management recommendations • Wales MAD P

18. Immediate Sources/Relevant Case Studies • REA studies • E. Channel Association • Irish Sea IMAGIN project • Bristol Channel Study

20. Wider Initiatives / Future Progress • MESMA- 4yrs R&D Monitoring and Evaluation of SMA’s • Tools, integrated strategies, methods, information systems, guidance, case studies. • MAGGNET • WG’s and STSMs, Publications • WGEXT – CRR, TOR’s • Specific National Initiatives e.g. • France (MDesprez) Review of impacts and Natura 2000 guidance (09) • UK classification typology under WFD, ALSF research. • Large projects EIA’s- • NL Rotterdam Harb - Maasvlakte 2 , Building with Nature. • Technological Advances- • Dredging equipment e.g. draghead pre-processors (Drabble UK)

21. Recognised R & D Priorities