Abstract |
A series of laboratory experiments was completed in 1994 and 1995 to test the main and interactive effects of temperature, pH, and prey level on survival, growth and production of striped bass larvae. Eggs and larvae of hatchery-spawned striped bass were tested in experiments run at the Chesapeake Biological Laboratory. Response surface modeling followed the experiments to determine critical levels of each factor and to test the models using field data from the Potomac and Nanticoke Rivers. Four kinds of experiments were run in which survival, size, growth rates and production were measured response variables: (1) Shock experiments were short-term tests of survival and growth responses of eggs, yolk-sac and feeding-stage larvae to sudden drops in temperature and pH. (2) Three-factor experiments were 16-day chronic exposure tests of larvae exposed to prey levels of 25, 100, and 400 Artemia nauplii per liter, pH levels of 6.2, 7.0 and 7.8 and temperatures of 16.0, 19.0 and 22.0 deg C (1994) or 15.0, 19,0 and 23.0 deg C (1995). (3) An Episodes experiment tested the effects of sudden drops in pH and temperature, when applied to larvae at either 4 or 9-days posthatch in 14-day experiments. (4) An experiment of Programmed fluctuations in pH and temperature tested for effects of constant, increasing, and episodic changes in pH and temperature during a 20-day experimental period. |