Entrainment of redfish (Sebastes spp.) larvae off the Scotian Shelf

Satellite images show large volumes of cold shelf water lying offshore of the Scotian Shelf in the spring of 1991. The seaward boundary of the shelf water was highly convoluted and indicated that shelf water was being entrained offshore into the slope water region by warm-core Gulf Stream eddies. An interdisciplinary field study of this region in late April and May found relatively high concentrations of redfish (Sebastes spp.) larvae in the entrained shelf waters, 100 km offshore of the shelf. Historical data indicate that these larvae were most likely spawned along the edge of the Scotian Shelf. Based on weight-at-length relationships, the larvae off the shelf were in poorer condition than those on the shelf. We suggest the larvae swept offshore eventually die, a result consistent with earlier studies that entrainment by Gulf Stream eddies negatively affects redfish recruitment.