Abundance, biomass and production of juvenile flatfish in southeastern kattegat

Abstract

Abundance, biomass and production of juvenile 0- and 1-group flatfish were estimated at 1.5 to 11.0 m depth from May 1984 to May 1987 in southeastern Kattegat. Species studied were: Plaice, Pleuronectes platessa (L.), sole, Solea solea (L.), dab, Limanda limanda (L.), turbot, Scophthalmus maximus (L.), brill, Scophthalmus rhombus (L.), and flounder, Platichthys flesus (L.). Highest abundance and biomass of 0- and 1-group flatfish occurred in July and August each year. Plaice, sole, turbot, brill and flounder were mainly found as 0-group at 1.5 to 5.0 m, but as 1-group they also occupied deeper water. 0- and 1-group dab occurred in the highest density at 5.0 to 11.0 m. Total summer (May to September) production at 1.5 to 5.0 m of the dominant species, plaice, sole and dab, were 98, 23 and 88 g AFDW per 100 m 2 during the three years investigated. Corresponding figures for the depth range 5.0 to 11.0 m were 12, 13 and 53 g AFDW per 100 m 2. Effects of eutrophication on the area as a nursery ground for flatfish are discussed.