PARENT SESSION
PM11 - Sediment Toxicology
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P324) Organic contaminants in feed used by, and sediments from under salmon aquaculture sites of Eastern Canada.
Hellou, Jocelyne*,1, Steller, Sean1, Haya, Kats2, Burridge, Les2, 1 Marine Chemistry Section, Marine Environmental Sciences Division, Dartmouth, Nova Scotia, Canada2 Environmental Sciences Section, Marine Environmental Sciences Division, St. Andrews, New Brunswick, Canada
ABSTRACT- Food pellets used in salmon aquaculture can vary in size from 1 to 10mm and contain an increasing level of lipids (20-30%), with ingredients deriving from offshore fisheries and land based products. Salmon aquaculture is prospering in New Brunswick and raises questions about the fate of unintentionally used lipophilic contaminants and their deposition around cages. Commercial food pellets, a fish oil used as an ingredient in feed, and sediments collected around cages in 1998-1999 were analysed for three groups of organic contaminants. Alkylated naphthalenes (NA) were detected in food pellets (25-51 ng/g, per NA), fish oil (116-180 ng/g, per NA) and sediments (<1-45 ng/g, dry, per NA), while other polycyclic aromatic hydrocarbons were detected at variable levels in sediments only (e.g. 23-1605 ng/g, dry for pyrene). Some PCB congeners and p,p-DDE were also detected at low levels in all samples. Trends were observed during the first year of sediment sampling, with up to 6-8 times higher organic carbon content and levels of PCBs and p,p-DDE below the cages relative to 25m away. During 1999 vs 1998 and therefore longer use of the sites, levels of p,p-DDE and PCBs were somewhat reduced under the cages but detected up to 100m away from the cages (<1.8 vs <7 ng/g, dry, for p,p-DDE and <1 vs <4 ng/g, dry, per PCB congener, 1999 vs 1998). Analyses of samples collected in 2000 are still ongoing. Level of contaminants determined in sediments will be compared to those reported at other locations around the world.
Key words: polyccylic aromatic hydrocarbons, polychlorinated biphenyls, DDE, transport