Effects of a Warm-Core Eddy on Fish Distributions in the Tasman Sea of East Australia

Abstract

Distributions of fishes were determined in and near a warm-core eddy off the east coast of Australia from 28 November to 13 December, 1978. Samples were collected with a midwater trawl (n = 39) in the upper 500 m of the water column during day and night. 88% of the 14 602 fish caught belonged to the family Myctophidae. Few fish ( < 4 % of total) were caught during day. At night the structure of the fish community within the eddy was recognizably distinct from that in surrounding water masses. Most fish distributions correlated well with thermal structure. Common species were categorized as eddy species (n = 5), outside eddy/cold-water species (n = 5), warm-water species (n = 1), cold-water species (n = 8) and widespread species (n = 7) based on nocturnal distributions.