ENVIRONMENTAL DISTRIBUTION OF ORGANIC WASTE FROM A MARINE FISH FARM

Organic components in marine sediments were determined along a transec t away from a salmon farm in western Norway. Dry weight, ash-free dry weight and total bacterial numbers gave a basic description of the sed iments. Pristane, elemental sulphur and fatty acids resulting from org anic enrichment from the farm were detected. The method used was solve nt extraction of the sediments and subsequent silica gel fractionation into aliphatic and aromatic hydrocarbons and polar components. The po lar components were subjected to methanolysis followed by ps chromatog raphy (GC) of the resulting fatty-acid methyl esters. The hydrocarbon fractions were analysed by GC directly. Amounts and composition were f ound to depend mainly on the distance from the farm site. Principal co mponent analysis was carried out on 20 representative fatty acids in f ish farm sediments, clean sediments, feed and fish faeces. A multivari ate correlation between the fatty acids and pristane indicated that th ese components may be used as chemical markers of disposal from an aqu aculture site.