Five data collecting stations were designated within Wilkes Reservoir, a 900 surface acre power plant reservoir in Marion County Texas, to gather information relative to the effects of a steam-electric effluent upon aquatic life. Temperature and dissolved oxygen readings were obtained with a YSI model 51A oxygen meter. Readings taken at designated intervals indicated the degree and extent of the heated water. Dissolved oxygen readings indicated no adverse dissolved oxygen concentrations. Twelve species of fish were collected and examined for external and internal parasites. Almost 59% of 161 game fish specimens, and almost 83% of 50 rough fish specimens were parasitized with trematodes, nematodes, cestodes, acanthocephalans, and parasitic copepods. The extent of parasitization in this reservoir indicated optimum or near optimum temperature conditions throughout the year. Parasitic copepods were more evident on bullhead catfish (lctalurus sp.) during February, March, and April. There did not appear to be any seasonal fluctuation of parasitization, or degree of infection on other parasites encountered. Plankton samples were collected with a plankton tow net and volumetrically measured in the laboratory. For a given date, the majority of the plankton consisted of copepods and was more numerous in the warmer water. However, plankton abundance within the entire reservoir was greater during the colder periods of the year. Chemical water quality was checked with a Hach DR EL portable chemistry kit and did not undergo any significant changes. Fish were collected in water with temperatures in excess of 100 F, surface temperature 107 F on afternoon of collection. Specimens netted in this heated water had high mortality rates.
