Effects of Trawling Subprogram: design, trial and implementation of an integrated long-term bycatch monitoring program, road tested in the NPF

Project number: 2002-035
Project Status:
Completed
Budget expenditure: $1,571,449.00
Principal Investigator: David T. Brewer
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 19 Oct 2002 - 21 Oct 2007
Contact:
FRDC

Need

The design and implementation of an integrated, long-term bycatch monitoring program has not been undertaken in any Australian prawn trawl fishery. The diversity and complexity of bycatch issues in most of these fisheries means that designing such a program is a significant challenge. The Northern Prawn Fishery (NPF) has been proactive in its support of research aimed at ensuring ecological sustainability, particularly regarding bycatch. This has shown significant benefit during the 'road tests' of EA's strategic assessment guidelines, with the NPF one of the few fisheries with a risk assessment of bycatch (FRDC 1996/257). The risk assessment highlighted species that were at highest risk from trawling, and there is now a need to take the next step and collect information on these species to determine the actual extent of this risk. There has also been a substantial amount of research evaluating the most suitable monitoring methods for this fishery. There is now a clear need to draw this information together in the design, trial and implementation of a monitoring program. This will be done in consultation with management, industry and other stakeholders. The program will then be handed over to NORMAC and AFMA for the long-term.
The NPF Bycatch Act ion Plan has committed to bycatch monitoring and a trial of a trained crew-member observer scheme for bycatch. Monitoring is needed in order for NORMAC to report against the commitments made in the BAP. This research also addresses NORMAC's high priori ty research area of the Effects of Fishing. It specifically addresses the priorities of assessing bycatch, ensuring the sustainability of bycatch and the development of monitoring programs for BRDs under commercial conditions. This research forms part o f an overall ecosystem management plan for the NPF and is critical to fulfilling NORMAC’s commitments in the NPF BAP and addressing the guidelines of EA's strategic assessment. The project also addresses FRDC Effects of Trawling subprogram priorities reg arding bycatch: “Methods for measuring and monitoring bycatch and the quantification of the direct impacts on associated populations and communities of bycatch species”.
The proposed project will address a range of issues currently faced by Australian f isheries, including
(i) how to establish a long term monitoring program for non-target species;
(ii) how the industry can best measure its impact on bycatch species;
(iii) how to increase industry’s ability to provide validated and high quality data on non-target species, that are acceptable to all stakeholders.
This project will provide the NPF with a cost effective process to demonstrate to the Australian and international community its willingness and ability to monitor its impacts on the species gr oups of most concern. This is an important step that will also have to be made by other Australian fisheries. We anticipate that the experiences gained and processes implemented during this project may be transferred to other fisheries. Consequently, it is hoped that there will be far-reaching benefits to the wider community arising from the projects completion.

Objectives

1. To design, trial and implement an integrated long-term bycatch monitoring program
that addresses (i) total amount of bycatch, (ii) protected species and (iii) high risk species in the most cost-effective manner possible using the NPF as an example.
2. To transfer ownership, momentum and responsibility of ongoing monitoring to NORMAC and AFMA.
3. Develop a new, innovative, quantitative method for defining the risk to the sustainability of bycatch species from prawn trawling, and apply the model to the bycatch of the NPF
4. Provide the first description of the bycatch from the Joseph Bonaparte Gulf.

Final report

ISBN: 1-921232-33-1
Author: David Brewer

Related research

Communities
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Environment

Effects of Trawling Subprogram: development of biodiversity and habitat monitoring systems for key trawl fisheries in Western Australia

Project number: 2002-038
Project Status:
Completed
Budget expenditure: $1,302,970.00
Principal Investigator: Mervi Kangas
Organisation: Department of Primary Industries and Regional Development (DPIRD) WA
Project start/end date: 13 Aug 2002 - 31 Oct 2007
Contact:
FRDC

Need

The need for this project was identified through the ESD/EA Risk Assessment workshops held for the Shark Bay and Exmouth Gulf trawl fisheries in May and October 2001. Research is required to provide baseline data on biodiversity on and off the trawl habitats in Shark Bay and Exmouth Gulf to allow an assessment of the effects of trawling on bycatch and to set up reference sites for long-term monitoring of the environmental impact of trawling. The study will examine seasonal variation in biodiversity and efficiency in capture of bycatch species to provide a rigorous scientific basis for determining references sites in other fisheries. Understanding seasonal variability will allow the selection of the appropriate timing of long-term monitoring. Depletion experiments will ensure that bycatch catch per unit effort is related to actual abundance. The sampling undertaken in Shark Bay will cover both prawn and scallop ESD requirements to enable similar reference sites to be established in all WA trawl fisheries. Bycatch issues in the Shark Bay and Exmouth fisheries were identified as a moderate risk through an Ecological Risk Assessment workshop. There is a need for a better understanding of the faunal composition and habitat preferences of bycatch species in both trawled and untrawled areas will aid in determining the most appropriate level of risk to bycatch species. This may allow management strategies to be developed to ameliorate any detrimental impacts on those species that are found to be highly vulnerable to trawl impacts. This information will also enable the Department of Fisheries and industry to effectively respond to information required by Environment Australia on the risk level, objectives, performance indicators and management responses for each issue in order to continue to provide quality and highly valued seafood to both export and local markets. It will also provide a basis to answer queries from conservation and community groups.

Objectives

1. To develop and compare biodiversity measures of trawled and untrawled habitats in Shark Bay and Exmouth Gulf and assess the implication of any differences.
2. To examine seasonal (to select timing of monitoring) and annual variation of biodiversity at representative sites in Shark Bay.
3. To examine the rate of depletion of selected bycatch species (indicator species) to ensure bycatch CPUE is related to actual abundance.
4. To assess age composition and size structure of indicator species and utilise the size composition proxy for age to assess basic productivity of species groups.
5. To develop criteria for selection of reference sites/times for future monitoring.

Final report

ISBN: 1-877098-90-6
Author: Mervi Kangas