Early Trend Determination of Organochlorine Contamination from Residue Ratios in the Sea Lamprey (Petromyzon marinus) and its Lake Whitefish (Coregonus clupeaformis) Host

Abstract

A detailed statistical evaluation of the levels of organochlorine contaminants in sea lamprey (Petromyzon marinus) and simultaneously caught lake whitefish (Coregonus clupeaformis) from the northern parts of Lakes Huron and Michigan is described. The analysis of residue ratios, both within each species and between, allows an immediate recognition of rising and falling trends of contamination with a high degree of confidence. This improvement over the conventional method of monitoring one species over several years is accomplished with comparatively little effort in sampling and chemical contaminant analysis. The described technique exploits the unique biological relationship of the lamprey and its host and is also based on the significantly shorter lifespan of the (adult) lamprey compared to that of the host. Rising trends in PCB and DDE contamination and declining trends for the levels of DDT, dieldrin, endrin, chlordane, hexachlorobenzene, heptachlorepoxide, and α-hexachlorocyclohexane were observed in 1978, the year of collection.Key words: organochlorine, contamination, trend, ratio, Petromyzon marinus, Coregonus clupeaformis