Undersøkelser på loddas gytefelt i 1972

Abstract

From 20 March to 24 April the R.V. «Johan Hjort» carried out a survey to locate spawning grounds of capelin. Included in this investigation was an estimation of the spawning potential based on capelin eggs and larvae. Eggs of capelin are demersal and usually found mixed with bottom substrata. Egg density was highest at bottom substrata with grain size between 0.5 to 1.5 cm in diameter. The greatest quantities of eggs were found at depths between 25 and 50 m, but eggs in small numbers occured down to 175 m. At the spawning grounds the temperature varied between 3.0 and 6.0º C. Eggs from Blodskyttodden, kept at temperatures between 3.0 and 3.5ºC started hatching after 45 days of incubation. Eiders were observed feeding on capelin eggs at depths down to 50 m. At some localities, haddock caught by trawl had a stomach content consisting mainly of capelin eggs