Abundance estimates of sprat (Clupea sprattus) by echo integrator in fjords of western Norway in autumn 1972

An echo survey for O-group sprat in the fjords of western Norway was carried out in late October 1972. An outline of the distribution is given together with relative estimates of abundance. Measures of abundance are compared with similar data from the previous year. A comparison is also made between indices of abundance obtained by an echo integrator in October 1971 and catches of sprat in June—October 1972. Correlation analyses demonstrate a fair relationship, but the index of abundance for some areas seems to be underestimated. Length distributions of sprat indicate that the O-group only is present in most areas. This group will support the 1973 sprat fishery in the fjords, and from the estimates of abundance the yield is predicted to be about the same as in 1972