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Waste to Energy Dublin Bay Baseline Study. Objective of the Study. To investigate the existing environmental conditions prior to the development of a Waste to Energy Facility on the Poolbeg Peninsula (Baseline Study)
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Objective of the Study • To investigate the existing environmental conditions prior to the development of a Waste to Energy Facility on the Poolbeg Peninsula (Baseline Study) • The baseline study will be used as background for the EIS which will be prepared by the developer once the design of the facility has been decided.
Agenda • Sources of information • Presentation of key results to date: -Water Quality - Sediments - Heavy metals in sediments - Benthic invertebrate fauna - Fish - Birds The presentation do not include any assessment of impacts of the facility
Sources of information • Data from literature and reports • Data from the monitoring programme carried out by Dublin City Council • Field studies
10 11 12 7 5 13 6 4 11 7 12 3 2 9 1 14 17 15 28 21 18 27 20 22 26 25 23 24 Water Quality MonitoringDublin City Council • Water quality surveys are carried out monthly from a boat. • Water samples taken from these stations are analysed for the following: DO, Salinity, Transparency, Temperature, pH, TON, Nitrite, Nitrate, Ammonia, Phosphate, Total Nitrogen, BOD, Total Phosphorus, Chlorophyll a, Phaeopigments, Total Colifroms and Faecal Coliforms.
10 11 9 8 12 7 5 6 13 6 4 5 3 4 11 7 12 3 2 9 1 14 17 15 28 21 18 27 20 22 2 26 25 1 23 24 Sediment and benthic fauna monitoring. Dublin City Council • Intertidal sampling sites. Stations indicated by black colour. Sediment samples taken yearly • Subtidal sampling site. Samples collected from sites 3, 6, 11, 13, 15, 25, 26, 27, 28 in 2002.and from all sites in 2003 • Parameters analysed for: Fauna, grain size, Loss on ignition, Cd, Cr, Cu, Fe, Mn, Pb, Zn and Hg
Depths and currents • Dublin Bay is open and broad at its mouth • Shallow water of less than 10 m depths • Current directions northerly with water entering the bay from the south and exiting at Howth
Protected areas Large areas of the bay are protected under the following designations: • Candidate Special Area of Conservation (cSAC)- supports examples of ten habitats listed in Annex 1 of the EU Habitats Directive • Special Protection Area under EU Birds Directive • Proposed National Heritage Area (NHA)
Water Quality The water quality of Dublin Bay is good with: • Low to sometimes moderate concentrations of organic matter and nutrients • Low concentration of phytoplankton • Well oxygenated water • Concentration of bacteria generally low. However, Merrion-, Sandymount- and Dollymount Strands do not comply with standards for Total and Faecal Coliforms
Sediments in Dublin Bay The following sediment types are encountered : • Mud (flats inTolka estuary and behind North Bull Isl.) • Sand (Intertidal flats) • Mixed substrates (Sutton) • Sand or sand mixed with mud (Subtidal areas)
Heavy metals in sediments • Heavy metals concentrations are generally low • However, heavy metals tend to accumulate in the muddy sediments of Tolka estuary • Highest concentration of Pb, Cd, Cr, Cu Zn in Tolka • Data compared with canadian sediment guidelines • TEL (threshold effect level)-concentrations below TEL not toxic • PEL (probable effect level). Concentrations above PEL are toxic • Concentrations between TEL and PEL-slight risk of toxic effects on fauna
Benthic invertebrate fauna • Benthic fauna is the fauna living in or closely associated with the seabed • Benthic fauna can be grouped in socalled communities each community including specific groups of organisms that co-occur in similar environments (Composition of grains size of sediments, organic matter content, depth etc)
Fauna Communities The following communities are found in Dublin Bay: • Tellina-community • Macoma-community • Abra community • Venus community Macoma Abra/Venus Tellina
Tellina community Characterizing species • Tellina tenuis • Tellina fabula Other species • Nereis diversicolor, Lanice conchilega, Eteone longa, Scolopos armiger, Nephtys hombergi, Bathyporeia sp. (5 species) Pontoporeia sp(2 species), Chorophium volutator, Crangon crangon Found from the tidal zone to 5-10 m on pure sandy bottoms Tellina tenuis
Macoma community Characterizing species • Macoma baltica • Cerastoderma edule • Scrobicularia plana • Arenicola marina Otherspecies: • Mytilus edulis, Nereis diversicolor, Scoloplos armiger, Nepthys hombergi, Capitella capitata, Oligochatea sp. and Carcinus maenas Found from the tidal zone to about 10 m on mixed bottoms
Abra community Characterizing species • Abra alba • Corbula gibba • Cultellus pellucidus • Nucula nucleus • Lagis koreni • Nephtys hombergi • Ophiura texturata Other species • Donax vittatus, Lanice conchilega, Scoloplos armiger, Eteone longa, Owenia fusiformis, Capitella capitata, Bathyporeia sp Found in sheltered areas on a mixed to muddy bottom rich in organic material. From 10 to about 30 m
Venus community Characterizing species • Venus gallina • Tellina fabula • Tellina tenuis • Mactra stultorum Other species • Same as Abra community Found on sandy bottom from 10 to 30-40 m Venus gallina
Benthic fauna in the Liffey • The river bed is virtually devoid of fauna from Kingsbridge to about 1.5 km below Butt Bridge, due to poor oxygen conditions • Further downstream fauna is present and progressively the fauna becomes more normal towards Poolbeg
Fish fauna Dublin Bay is an important habitat for fish: • Dab and plaice most abundant demersal (bottom dwelling) species. Flounder, Whiting and Common dragonet also quite common. • Seasonal immigrations of Sprats, Herring, Mackerel, Mullets, Pollacks, Bass and Codlings. • Nursery area for several species including dab, plaice, flounder and whiting • Zone of passage of migrating salmon and sea trout. Demersal (bottom dwelling) fish species in Dublin Bay. Percentage of total numbers of different species caught during surveys carried out in 1996 and 1998. The fish were caught by R.V Lough Beltra and the R.V Celtic Voyager using small mesh beam trawl over a distance of 500 m at six sites in Dublin Bay.
Plaice. Spawning and nursery areas • Spawning: Important spawning area off the north-east coast of Ireland from Dublin in the south to Dundrum Bay in the north. Spawning between late January to early May with peak spawning during March • Larval development: eggs and larvae pelagic-carried by the currents, staying mainly in the very productive Western Irish Sea gyre. Metamorphose to juvenile plaice eventually it settles on the bottom as a proper flatfish. • Nursery areas: Juvenile plaice found in shallow inshore water usually sandy beach areas . Most important areas along the Irish coast are located on the stretch from Strangford to and including Dublin Bay .
Whiting Spawning and Nursery areas • Spawning areas: One of the main spawning areas for whiting in the Irish Sea is off the Irish coast between County Down and Dublin Spawning takes place from February to June. • Larval drift. Eggs and larvae are pelagic and are carried by the currents, and are found in the coastal bights • Nursery areas: Juvenile whiting are found in nursery areas over sandy and muddy coastal areas and estuaries Dublin Bay is a nursery area for whiting • After the first year of life it migrates to the open sea
Conclusion • The water quality of Dublin Bay is generally good • Heavy metals concentrations are generally low • However, heavy metals tend to accumulate in the muddy sediments of Tolka estuary There is a rich fauna of benthic invertebrates in Dublin Bay. The following benthic fauna communities are found : Tellina-,Macoma-,Abra- and Venus communities • In the Liffey, the river bed is virtually devoid of fauna from Kingsbridge to about 1.5 km below Butt Bridge, due to poor oxygen conditions. Further downstream fauna is present and progressively the fauna becomes more normal towards Poolbeg • Dublin Bay is an important habitat for fish. It is nursery area for several species including dab, plaice, flounder and whiting. The Bay is Zone of passage of migrating salmon and sea trout.