CSI Great Lakes: Fish forensics

Capital News Service

LANSING — Some trout in Great Lakes tributaries are just as contaminated with a chemical linked to respiratory, liver and skin ailments as the Pacific salmon that they eat, according to a new study. The findings should help those making decisions on eating fish, dam removal and stocking, according to the researchers. Pacific salmon, such as Chinook and coho, are large sports fish that live most of their lives in the Great Lakes and then spawn and die in rivers and streams.
The study by University of Notre Dame biologists looked for PCBs (polychlorinated biphenyls) in salmon tissue during autumn spawning runs in tributaries of lakes Huron, Michigan and Superior. It compared that tissue with the tissue of native brook trout and mottled sculpin that live full time in the same rivers and eat the eggs and flesh of the salmon. The results showed the organic pollutant levels of the two types of fish are a close match in those living in Lake Huron and Lake Michigan tributaries.