Effect of thermal stress on larvae of Patiria miniata (Brandt) including studies on induction of spawning, development and larval tagging

It has been estimated by the Department of the Interior that by 1985 nearly one-quarter of all surface water in the United States will be used in removal of waste heat produced in electric generation. This will involve subjecting tremendous quantities of plankton to rapid fluctuations in temperature. The biological effect of such treatment on primary productivity and composition of zooplankton populations is not fully understood. To date little published information is available on the effect of rapid temperature fluctuations on plankton. Such temperatures are the result of heat exchange found in the cooling system of a steam-generating electric station. Patiria miniata is a dominant member of many subtidal and intertidal communities and consequently is an ecologically important species. Additionally, the adults can be induced to spawn throughout the year on demand, providing a constant source of larvae for experiments Larvae of P. miniata may be cultured from egg to juvenile in the laboratory with relative ease. The first 3 sections of this thesis describe techniques and baseline data used to conduct the primary experiment. The first section determines the minimum concentration of l-methyladenine required to induce spawning and if variations in quantity or concentrations had any significant effect on spawning times. Development and growth, the second section, sets limits for what will be considered “normal” larvae. The third section of this project describes the use of biological stains as a means to identify larvae receiving varying treatments when cultured en masse. The primary purpose and last section of this report is to answer the question how much of a thermal shock can the larvae of P. miniata withstand and still continue normal development