Ecological adaption of reproduction in Arctic cod
1984
The proceedings of the Soviet-Norwegian symposium on: Reproduction and recruitment of Arctic cod. Leningrad 26 - 30 September 1983.
显示更多 [+] 显示较少 [-]A recent period (1977-1982) of cold climate in the BarentsSea resulted in a greatly reduced feeding area available forthe Arctic cod and in consistent low recruitment. With thestart of a warmer period in 1982/83 the area and potentialfor production of cod biomass expands and recruitment hasincreased. An hypothesis is presented that through evolutionaryprocesses the reproduction of the Arctic cod isadjusted to the variations in the feeding area caused byclimatic fluctuations. Historical data on sea temperatureand ice cover are used to describe the climatic fluctuationsfor the period 1900-1983 and these are compared with data onfluctuations in yearclass strength. It is concluded thatconditions favouring high survival rates of cod larvae mustbe related to the occurrence of high temperatures in theAtlantic component of the Norwegian current. The processesand/or phenomena must have a large time- and space scale.This is also confirmed by the high incidence of tempora1similarity in survival success of the stocks of cod, haddockand herring in this area.
显示更多 [+] 显示较少 [-]