Fisheries long term monitoring program : summary of the Gulf of Carpentaria Developmental Finfish Trawl Fishery survey results: 2004-2006

Abstract

The Gulf of Carpentaria Developmental Fin Fish Trawl Fishery (DFTF) predominantly captures tropical red snappers including the crimson snapper (Lutjanus erythropterus) and the saddletail snapper (Lutjanus malabaricus); however, a variety of other valuable species are also retained as saleable product. The DFTF is a commercial quota managed fishery with a maximum allowable level of 1500 t of crimson snapper, saddletail snapper, red emperor and other emperor with a commercial Total Allowable Catch (TAC) set annually. The current commercial TAC is set at 1250t.

Reported total catch for this developmental fishery was variable between 1998 and 2001 with as little as 7 t reported in 2001. Since 2001, total catch has increased each year with 613 t reported in 2006 ($2. million). The crimson and saddletail snapper together comprise 55% of the average total annual catch by weight (2002-2005), with 36% and 19% for each species respectively.

The key objectives of the Long Term Monitoring Program were to analyse the subsample of crimson and saddletail snappers collected by fisheries observers from commercial fishing operations to provide biological data to fisheries management including:

• fish length to weight relationships
• reproductive indices (gonosomatic indices - the ratio of the weight of a fish's ovary or testis to its total body weight)
• reproductive stage data (macroscopic)
• sex ratios.