Sprat spawning in two fjord areas of western Norway in 1982 and 1983

Abstract

A southern and a northern fjord at Western Norway were surveyed for sprat spawning from the end of May until July, six times in 1982 and four times in 1983. Sprat spawned in both areas and the surveys covered just a part of the spawning season. It is allowed for the stage duration, using the mean temperature for the sampling depths at each station and cruise. Thus the daily egg production was estimated for each station and for each of the fjord areas as a whole for each cruise. The spawning curves show peak spawning at the end of May - first part of June. From the area underneath the egg production curves the total egg productions were estimated. Attempts are made to estimate the size of the spawning stocks from the egg productions and published data on fecundity.