The New South Wales Trawlfishery: Review of Past Course and Examination of Present Condition

Abstract

The past course of the New South Wales mixed trawlfishery is reviewed mainly on the basis of the available catch and fishing effort statistics.

The size composition of tiger flathead landings from 1946-47 to 1953-54, and the age composition for certain post-war years, are analysed in conjunction with catch per unit effort data. The results suggest that 1943-44, 1944-45, 1947-48, and 1948-49 were relatively poor brood years, and 1945-46 and 1946-47 relatively good.

The fluctuations in availability of tiger flathead (Neoplatycephalus macrodon (Ogilby) ) are accounted for after making certain valid assumptions. It is considered probable that the unexpectedly low catches of tiger flathead in the immediate post-war years were due to inefficiency of the few steam trawlers then working, and that Danish seiners were unable to exploit fully the available V+ and higher age-group fish.

An examination of the present situation indicates that the New South Wales stock of tiger flathead is at a low level and is likely to reach even lower levels in the future if fishing intensity remains as high as in 1953-54.

An improvement of the existing catch per unit effort would be expected if fishing intensity was reduced to the level of the middle nineteen-thirties (i.e. approx. 3500 trawler-tons) .

Other regulative measures would need to be introduced to bring about an improvement in the annual catch of tiger flathead. These measures should aim at ensuring a more favourable weight-length relation.