Effects of exposure to time-excess temperature histories typically experienced at power plants on the hatching success of fish eggs

Blueback herring, alewife, American shad, white perch and striped bass eggs were subjected to time-temperature histories typically experienced by organisms that are either carried through the once-through cooling system of a power plant, or are entrained into the thermal plume without passing through the plant. The maximum excess temperature tested ranged from 6–10 °C and the time of exposure to a maximum AT from 2.5–60 min. The period of cooling to the final temperature ranged from 60–300 min. For each species, six to eight experiments were run on six to twelve sub-samples of 200–400 eggs from a single female. Several different stages of development were tested. Analyses of variance showed that for each species the differences in hatching success among the various time-temperature treatments, including the control treatment, were not significant at the 1 % level. Further, for each species the mean hatching success of the controls did not differ significantly from the mean hatching successes associated with any of the experimental time-temperature treatments. The investigator concludes that exposure of fish eggs of the species and development stages tested to these timetemperature histories does not significantly affect their hatching success.