Environmental influences on recruitment in the saucer scallop (Amusium balloti) fishery of Shark Bay, Western Australia

The saucer scallop (Amusium balloti) fishery in Shark Bay is part of a multispecies fishery in which some vessels also fish for prawns. The scallop fishery, which has been fully exploited since 1984, has shown large variations in annual catch (from 120 to 7301 meat weight), reflecting variations in annual recruitment. The strength of recruitment is significantly correlated (r = -0.86, n = 7 years) with a major oceanographic process off the West Australian coastline, the Leeuwin Current, during the spawning season. The strength of this current is strongly influenced by El Nino/Southern Oscillation (ENSO) events. Possible modes of action of the current include the flushing of larvae away from suitable grounds and/or reduced spawning stimulus. The stock-recruitment-environment relationship indicates that the spawning stock has not significantly affected recruitment after taking into account the environmental effect. The high correlation (0.81) between the abundance of pre-recruit scallops and the catch in the following year allows the catch to be predicted from surveys of pre-recruits.

Article from Marine Science Symposia Vol. 199 - "Shellfish life histories and shellfishery models". Symposium held in Moncton, New Brunswick, 25-29 June 1990. To access the remaining articles please click on the keyword "MSS Vol. 199".