A comparison of food habits of white perch (Morone americana) in the heated effluent canal of a steam electric station and in an adjacent river system.

Analysis of the stomach contents of 97 white perch, Morone americana, taken from the effluent canal of a steam electric station (S.E.S.) and 106 white perch from adjacent Patuxent River waters indicated similar food habits from September 1970 through August 1971. However, 35% of all white perch taken from the heated effluent canal contained small pieces of coal and cinders, whereas only 3% of the river specimens contained such items in their stomachs. Fly ash and coal dust are present on the bottom of the S.E.S. canal, whereas little such material, if any, can be found on the river bottom in the study area. This suggests the canal fish were actively feeding in the heated effluent and not simply moving into the canal after feeding in the river. No significant difference (Pgreater than0.05) was found between the average wet weight stomach contents of the river and canal fish within the same mouth.