The dispersion of sole, Solea solea and plaice, Plemonectes platessa within and away from a nursery ground in the Irish Sea

Abstract

Populations of sole and plaice were sampled on and around a nursery on the North Wales coast during May, July arid October 1989 and 1990, and the distribution of age‐groups described. Pre‐recruit sole were tagged and reieased on the same area during September 1988 to provide information on their larger scale movements. Juvenile sole remained on the nursery ground close inshore until after their first winter, whereas plaice of the same age—group became more widely dispersed. Both species were still associated with the coastal zone as 2‐groups, when they were vulnerable to capture by commercial trawls. The gradual movement of sole out of the nursery was almost complete by October of their third year. Sole tag returns were obtained mainly from the NE Irish Sea. and also from the E coast of Ireland. Only three of the 68 returns came from outside the Irish Sea, one from the SE Irish coast, one from Swansea Bay and another from the outer Bristol Channel. Published data indicated that plaice undergo more rapid and more extensive migrations within and away from the Irish Sea than sole of the same age‐group. Juvenile plaice and sole populations from nursery grounds throughout the NE Irish Sea would become mixed, and could contribute to any of the spawning populations in that area.