1. Matthew Service Anthropogenic Pressures Anthropogenic Pressures

2. Principal Pressures Physical disturbance from direct impacts and resulting from morphological changes Physical disturbance from direct impacts and resulting from morphological changes Contaminants; Heavy metals and Organic Contaminants; Heavy metals and Organic Nutrients Nutrients

4. Residual near surface circulation Potential energy anomaly (J m 3 ) and drifter tracks 1. Introduction

5. Time line 1857 Dickie reports presence of M modiolus in Lough: 1857 Dickie reports presence of M modiolus in Lough: oysters in “central area” oysters in “central area” cf 1900 Oyster fishery declines: cf 1900 Oyster fishery declines: cf 1930 Spartina introduced; cf 1930 Spartina introduced; Boyd (1969) describes plankton and water quality; Boyd (1969) describes plankton and water quality; Jenkinson(1974) Describes hydrodynamics Jenkinson(1974) Describes hydrodynamics 1970 first reports of Queen Scallop trawling: 1970 first reports of Queen Scallop trawling: Erwin 1977 Describes S Lough Benthos Erwin 1977 Describes S Lough Benthos

6. Roberts 1975 Describes M modiolus/Chlamys varia community; Roberts 1975 Describes M modiolus/Chlamys varia community; 1978 Spartina spraying started; 1978 Spartina spraying started; 1979 Parker report on shellfish contaminants forerunner of Musselwatch study; 1979 Parker report on shellfish contaminants forerunner of Musselwatch study; 1984 Investigation in double shelling and links with TBT; 1984 Investigation in double shelling and links with TBT; 1984 Spartina spraying implicated as cause of sediment release; 1984 Spartina spraying implicated as cause of sediment release; Late 1980’s Queen Scallop trawling expands; Late 1980’s Queen Scallop trawling expands;

7. 1985 Ardmillan Bay designated under EC Shellfish Waters Directive; 1985 Ardmillan Bay designated under EC Shellfish Waters Directive; 1989 Brown publishes report claiming trawling is destroying M modiolus communities; 1989 Brown publishes report claiming trawling is destroying M modiolus communities; 1990 DOE(NI) Commission Mathematical Model 1990 DOE(NI) Commission Mathematical Model 1990 ISD report confirms trawling having impact; 1990 ISD report confirms trawling having impact; 1993 DANI(DARD) introduces fishing restrictions; 1993 DANI(DARD) introduces fishing restrictions; 1993 DARD report on sediment metals 1993 DARD report on sediment metals 1995 Possible introduction of Sargassum 1995 Possible introduction of Sargassum 1996 Magorrian Thesis on Effects of commercial trawling (DARD studentship); 1996 Magorrian Thesis on Effects of commercial trawling (DARD studentship);

8. 1997 Spartina spraying resumed; 1997 Spartina spraying resumed; 1997 DARD project on Recovery of benthic communities project initiated 1997 DARD project on Recovery of benthic communities project initiated DARD/EHS report on Trophic Status of Lough DARD/EHS report on Trophic Status of Lough 1998-2000 Further DARD Report on Sediment Contaminants 1998-2000 Further DARD Report on Sediment Contaminants 1999 Sea defence reconstruction begun at Newtownards; 1999 Sea defence reconstruction begun at Newtownards; 2001 Release of sediment from Killyleagh foreshore; 2001 Release of sediment from Killyleagh foreshore;

9. Eutrophication Eutrophication Trace Contaminants (Heavy metals and organics) in sediments; Trace Contaminants (Heavy metals and organics) in sediments; Shellfish contaminants; Shellfish contaminants; Physical disturbance; Physical disturbance; Algal toxins: Algal toxins:

10. Routine Monitoring EC Shellfish Waters Directive EC Shellfish Waters Directive EC Shellfish Hygiene Directive EC Shellfish Hygiene Directive National Marine Monitoring Plan (OSPAR JAMP) National Marine Monitoring Plan (OSPAR JAMP) EHS Estuarine Classification EHS Estuarine Classification

11. Water Quality: DARD/QUB AESD conducted a spatial and temporal survey of nutrient loading to the lough and nutrients, phytoplankton and chlorophyll in the lough over the period 1993-1996. DARD/QUB AESD conducted a spatial and temporal survey of nutrient loading to the lough and nutrients, phytoplankton and chlorophyll in the lough over the period 1993-1996. EHS estuarine class programme collects limited low frequency nutrient and plankton data.EHS also monitor heavy metals in water as part of the EC Shellfish Waters monitoring. EHS estuarine class programme collects limited low frequency nutrient and plankton data.EHS also monitor heavy metals in water as part of the EC Shellfish Waters monitoring. DARD- AESD analyse samples from active shellfish sites for presence of toxic algae fortnightly. This is reported annually. DARD- AESD analyse samples from active shellfish sites for presence of toxic algae fortnightly. This is reported annually. EHS-EP report input data from Ballyrickard STW, Killyleagh STW and Downpatrick STW.- the Quoile. EHS-EP report input data from Ballyrickard STW, Killyleagh STW and Downpatrick STW.- the Quoile.

12. Loads(KG) 0 500 1000 1500 2000 2500 CADMIUMGAMMA-MERCURYPCB 118PCB 153PCB 28ZINC TOTAL Loads(KG) OSPARCOM Loading Data

13. Nutrient Drivers: EC UWWT Directive EC UWWT Directive EC Nitrates Directive EC Nitrates Directive

14. Eutrophication is defined by the EC (in the Urban Waste Water Treatment Directive) as: Eutrophication is defined by the EC (in the Urban Waste Water Treatment Directive) as: the enrichment of waters by nutrients, especially compounds of nitrogen and/orphosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned the enrichment of waters by nutrients, especially compounds of nitrogen and/orphosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned

15. Taylor and Service (1998)concluded Taylor and Service (1998)concluded Irish Sea is the largest source of nitrogen, phosphate and silicate loading to Strangford Lough Irish Sea is the largest source of nitrogen, phosphate and silicate loading to Strangford Lough The total annual anthropogenic load of DIN and SRP (excluding the Irish Sea and airborne deposition) to the Lough are 1 201 and 116 tonnes, respectively; The total annual anthropogenic load of DIN and SRP (excluding the Irish Sea and airborne deposition) to the Lough are 1 201 and 116 tonnes, respectively;

16. Eutrophication is defined by the EC (in the Urban Waste Water Treatment Directive) as: Eutrophication is defined by the EC (in the Urban Waste Water Treatment Directive) as: the enrichment of waters by nutrients, especially compounds of nitrogen and/orphosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned the enrichment of waters by nutrients, especially compounds of nitrogen and/orphosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned

21. Heavy Metals Killyleagh outfall generated more than 10 tonnes of chromium per annum, although during the early 1990s, declined to nearer 1 tonne per annum; Killyleagh outfall generated more than 10 tonnes of chromium per annum, although during the early 1990s, declined to nearer 1 tonne per annum; The high mercury concentration in mussels from Whiterock were similar to those found in mussels from the Inner Forth estuary in Scotland (Davies and Pirie 1980 in Gault et al. 1983) ; The high mercury concentration in mussels from Whiterock were similar to those found in mussels from the Inner Forth estuary in Scotland (Davies and Pirie 1980 in Gault et al. 1983) ; TBT Implicated in double shelling in oysters; TBT Implicated in double shelling in oysters;

23. TBT Routine monitoring for Imposex and Intersex in Dogwhelks and Winkles by EHS has shown little sign on effect; Routine monitoring for Imposex and Intersex in Dogwhelks and Winkles by EHS has shown little sign on effect; Edwards (2002) Suggested that Imposex records in Whelks show a reduction in TBT levels. Edwards (2002) Suggested that Imposex records in Whelks show a reduction in TBT levels.

24. Sediment Quality In 1990 approximately 30 samples were analysed at the <63um particle size level using an aqua regia digest In 1990 approximately 30 samples were analysed at the <63um particle size level using an aqua regia digest In 1996 a smaller numbers of stations were sampled and analysed for heavy metals at the <2mm particle size level using an HF digest for geochemical normalisation. In 1996 a smaller numbers of stations were sampled and analysed for heavy metals at the <2mm particle size level using an HF digest for geochemical normalisation. Hydrocarbons (PAH’s) a spatial survey was carried out in 2000 at again about 12 sites. Hydrocarbons (PAH’s) a spatial survey was carried out in 2000 at again about 12 sites. DARD have one NMMP sediment station in the Lough that is sampled for heavy metals, pesticides, PAH’s. DARD have one NMMP sediment station in the Lough that is sampled for heavy metals, pesticides, PAH’s. EHS –EP have sediment sampling sites(4?) in the lough as part of their Estuarine Classification Monitoring EHS –EP have sediment sampling sites(4?) in the lough as part of their Estuarine Classification Monitoring

26. Service (1993) concluded that with the exception of chromium and mercury, all other metals show strong co-correlation and are therefore from a common, geochemical weathering source. By contrast, chromium and mercury are most likely to originate from the point source outfall at Killyleagh. Service (1993) concluded that with the exception of chromium and mercury, all other metals show strong co-correlation and are therefore from a common, geochemical weathering source. By contrast, chromium and mercury are most likely to originate from the point source outfall at Killyleagh.

27. 2. Trace metal contamination

28. Irish Sea Sites Sediment Metals 2000 0 20 40 60 80 100 120 140 160 180 NMP4nmp538aNMp3s lough AL Cu PB NI Zn AS CR B

30. Heavy Metals in Modiolus modiolus 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 AgCdCrCuFeHgNiPbZnAs Donaghadee S Lough *10

31. Physical disturbance due to: Physical disturbance due to: Trawling or dredging; Trawling or dredging; Sediment relocation: Sediment relocation: Release of sediment or changes in coastal cell Release of sediment or changes in coastal cell change in prevailing wind change in prevailing wind

32. Otter Boards or trawls hold the net open and may impact the sea bed Sediment plumes may help “herd” fish Tickler chains banned in Strangford Lough

37. The worst damage caused by otter boards The worst damage caused by otter boards The area between scars showed no textural differences The area between scars showed no textural differences area effects has a characteristic texture area effects has a characteristic texture

39. Side-scan sonar survey area Side-scan sonar survey area

41. Strangford is subject to variety of pressures Strangford is subject to variety of pressures arising both from the catchment and directly arising both from the catchment and directly there is no evidence that the Lough is eutrophic or heavily contaminated there is no evidence that the Lough is eutrophic or heavily contaminated trawling can impact seabed communities trawling can impact seabed communities