Characteristics of spawning-run smelt, Osmerus eperlanus (L.), from a Scottish river, with recommendations for their conservation and management

Abstract

. Overexploitation and pollution has led to the decline of Scotland's traditional smelt fisheries. The one remaining commercial fishery is on the River Cree in south-west Scotland and the characteristics of the spawning runs of the smelt, Osmerus eperlanus (L.), on which this fishery is based have been studied with a view to conservation and re-establishment of the species elsewhere in Scotland. The spawning-runs which started in early March when water temperatures were greater than 5°C were characterized by marked temporal changes in size, age and sex ratio. The fish enter the spawning stock at 1+ years of age and, in common with other estuarine smelt populations, are highly fecund. The spawning stock was composed mainly of two age-classes (1+ and 2+ years) and fish of the 1978 year-class dominated the spawning stock in 1980 and 1981. Spawning, which was interrupted during periods of high flow, lasted about 1 week. Male fish tended to remain on the spawning grounds after females had vacated the area. Recommendations for management and re-establishing smelt stocks are discussed.