NATURALLY SPAWNING CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) FROM THEEFFLUENT OF A WASTE-WATER TREATMENT-PLANT

Chinook salmon (Oncorhynchus tshawytscha) observed spawning in the Eas t Chicago Sanitary District Earthen Channel, East Chicago, Indiana. La ke-wide genetic variation among stocked salmonids is believed to be re latively high in this species and is reflected in the allozyme variati on observed in the survey of spawning adults taken from the Earthen Ch annel. As an addendum to visual observation of salmon spawning and to collections in 1995 of parred juveniles within this tributary, allozym e data were obtained as a preliminary assessment of populational genet ic structure. These data will form a basis for comparative studies in future years. This was the first observation and collection of parred and smelt chinook salmon from a single natural spawn in the southern b asin of Lake Michigan.