DISCRIMINATION AMONG SPAWNING CONCENTRATIONS OF LAKE SUPERIOR LAKE HERRING BASED ON TRACE-ELEMENT PROFILES IN SAGITTAE

Little is known about the stock structure of lake herring Coregonus ar tedi in Lake Superior, and recent increases in harvestable stock sizes has led to expanded exploitation in some areas. Research on marine te leosts has demonstrated that chemical differences in sagittal otoliths can be used for identification of fish stocks. We used plasma emissio n spectrophotometry to measure the concentrations of 10 trace elements in the sagittal otoliths from lake herring captured at eight spawning sites in Lake Superior and from Little Star Lake, an inland lake outs ide the Lake Superior basin. Discriminant function analysis indicated that elemental concentrations provided site-specific information but t hat considerable overlap existed among some locations, especially thos e in western Lake Superior. Correct classification rates varied from 1 2.0% to 86.1% and were generally higher for spawning locations from em bayments in eastern Lake Superior and for the outgroup population from Little Star Lake. The results presented here demonstrate the potentia l usefulness of this technique for strictly freshwater species, especi ally those that live in highly oligotrophic waters such as Lake Superi or.