Development and mortality of cod (Gadus morhua L.) eggs and larvae in different temperatures. In: The propagation of cod Gadus morhua L.: an international symposium, Arendal, 14 - 17 June 1983

Abstract

This experiment was carried out as a part of a project concerning thermal pollution from a power plant. The paper deals with development and mortality of cod eggs and larvae in different temperatures (6O-18 degrees C). Eggs and larvae were exposed to higher temperatures for parts of the incubation time and the yolk sac period. The development rate increased with increasing temperatures. The mortality increased significantly above 12 degrees C, but was rather low below this temperature. Newly fertilized eggs exposed to higher temperatures seemed to be affected more seriously than eggs exposed to higher temperatures later in the incubation period. Newly hatched cod larvae exposed to high temperatures showed no significant increase in the mortality rate. The yolk sac period decreased with increasing temperature. Short temperature shocks (at about 10 degrees C for 15 min) did not affect the mortality rate of eggs and larvae significantly.