Project number: 2009-069
Project Status:
Completed
Budget expenditure: $74,970.00
Principal Investigator: Cameron Dixon
Organisation: SARDI Food Safety and Innovation
Project start/end date: 28 Feb 2010 - 30 Aug 2011
Contact:
FRDC

Need

This study is seen as a platform that will pave the way for a committed ongoing program of assessing, refining and ultimately adopting bycatch mitigation strategies in temperate South Australian prawn fisheries. This project was conceived from a high priority need to develop and test enhanced gear technologies that aim to: 1) reduce the incidental capture of bycatch species and 2) reduce the capture of small prawns. Both have the potential to maximise the value of the resource. This need was highlighted in the recent Gulf St Vincent prawn fishery (GSVPF) assessment report (Roberts et al., 2009).

The GSVPF is about to embark on a bycatch risk assessment process that will include a bycatch survey (March 2010), which will provide a unique opportunity to conduct this research in parallel at a significantly reduced cost.

This project will provide a template that utilises current fishery-independent trawl surveys to test new gear technologies. This work would follow on from previous valuable catch selectivity research (square mesh), and will provide management and industry with options for the way forward in terms of bycatch mitigation. This project will evaluate the effectiveness of novel trawl mesh (T90) at optimising catch selectivity and will be underpinned by pilot trials to be conducted at the expense of industry and SARDI. Furthermore, valuable underwater footage of operational trawl nets will be captured for the purpose of informing and optimising current and future net modifications / BRD trials (gear and bycatch behaviour). Information on species-specific trawl vulnerability, behaviour and differences in gear designs would augment the ecological risk assessment that the industry are undergoing.

Objectives

1. To provide a platform to test and develop enhanced gear modifications that minimise bycatch in temperate prawn trawl fisheries
2. To evaluate catch selectivity (prawn size and species-specific bycatch composition) of conventional diamond vs novel trawl mesh (T90) of two configurations
3. To capture underwater video footage of operational demersal trawl nets (conventional and modified) in a temperate prawn fishery to inform and optimise current and future net modifications / Bycatch Reduction Device (BRD) trials (gear and catch behaviour)

Final report

ISBN: 978-0-7345-0420-3
Author: Cameron Dixon

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