Trials of T-90 Mesh Configuration

Trials of T-90 mesh configuration in the Great Australian Bight Trawl Fishery (FRDC Project 2007/063) by Ian Knuckey, Russell Hudson, Matt Koopman, Semi Skoljarev and Jeff Moore (2008)

This trial has demonstrated that the use of T-90 nets may help to reduce unwanted incidental catches of small fish without undue loss of commercially valuable species. The reduction in discarded catch from the T-90 net was particularly large during day time shots. In addition, deepwater flathead caught in the T-90 net had slightly less damage than those caught in the control net. These results have been communicated to industry and management and further exploration of the costs and benefits of using T-90 nets during normal commercial fishing activities would be beneficial. Wider use of this net by industry would be a positive step towards meeting the fisheries obligations of reducing discarding in accordance with AFMA’s Program for Addressing Bycatch and Discarding in Commonwealth Fisheries – An Implementation Strategy, but may have some financial cost. At least one vessel is continuing to use a T-90 net during normal commercial fishing operations. 

The Great Australian Bight Trawl Fishery (GABTF) is a sub-fishery of the Southern and Eastern Scalefish and Shark Fishery (SESSF), managed by the Australian Fisheries Management Authority (AFMA). The fishery targets two main species on the outer continental shelf: deepwater flathead (Neoplatycephalus conatus) and Bight redfish (Centroberyx gerrardi), but catches many other byproduct and bycatch (discarded) species. As part of its Bycatch Action Plan, the Great Australian Bight Industry Association (GABIA) has been working with AFMA to reduce discarding in the fishery. GABIA wanted to trial a new “T-90” net to examine the potential to reduce bycatch, improve fish quality and maximise fuel efficiency, with the overall aim of increasing the profitability of fishing operations.

T-90 nets have been shown in international studies to improve both selectivity and towing efficiency. It is also suggested that T-90 nets have the added benefit of being “gentler” on the catch than standard nets because turbulence in the codend is reduced. GABIA had designed and purchased a purpose built T-90 net in order to conduct tests to determine if the benefits observed in other countries could be replicated in the Great Australian Bight, without compromising catch of target species. 

This report details the results of the T-90 net trial.