3 results

Shark and other chondrichthyan byproduct and bycatch estimation in the SEF Trawl and non-trawl Sectors

Project number: 2001-007
Project Status:
Completed
Budget expenditure: $66,350.00
Principal Investigator: Terence I. Walker
Organisation: Agriculture Victoria
Project start/end date: 13 Jul 2001 - 30 Oct 2007
Contact:
FRDC

Need

Australia is a signatory to the International Plan of Action for the Conservation and Management of Sharks (IPOA-Sharks) which was ratified by the United Nations Food and Agricultural Organisation (FAO) Committee of Fisheries during February 1999. As a signatory, Australia is obliged to develop a National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks).

AFFA has established a Shark Advisory Group to prepare a Shark Assessment Report and to develop the Australian NPOA-Sharks. The Group includes representatives from all key government and non-government stakeholder groups, including shark specialists. Progress on development of the Report and Australia's NPOA-Sharks was reported to the FAO Committee of Fisheries during February 2001.

In addition, through the Standing Committee on Fisheries and Aquaculture, all Australian Commonwealth and State fisheries ministers have endorsed the National Policy on Fisheries Bycatch, which includes sharks and other chondrichthyans. The Commonwealth has recently released its bycatch policy, which builds on the endorsed National Policy on Fisheries Bycatch and commits the Commonwealth to developing a Bycatch Action Plan for each major Commonwealth fishery by 31 March 2001.

Australia is well placed to meet its international and national obligations for conservation and management of its chondrichthyan species. The major shark fisheries of southern Australia, Western Australia and northern Australia are well documented and are data rich. However, biproduct and bycatch of these species are not well documented.

In south-eastern Australia, most chondrichthyans are taken by the Southern Shark Fishery (SSF) and South East Fishery (SEF). Data on byproduct and bycatch have been collected from the SSF and are currently being analysed (FRDC Project 99/103). In the SEF, data are collected by Integrated Scientific Monitoring Program, but no attempt has been made to analyse the chondrichthyan data.

The present project proposal will not be complete in time to provide results for the first draft of the Australian Shark Assessment Report and NPOA-Sharks. Similarly, it will not be complete in time to prepare Bycatch Action Plans for the SEF (Trawl Sector) and the SSF and SEF (Non-trawl Sector) but the project outputs will be vital inputs to subsequent drafts.

Outputs from the project will assist Environment Australia with two recent initiatives taken under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999. One relates to the requirement for an Environment Impact Assessment for each Commonwealth managed fishery. The other initiative is the Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes.

Objectives

1. Summarise retained and discarded catches and length-frequency data on sharks, skates, rays and chimaeras from the Integrated Scientific Monitoring Program (ISMP) database.
2. Estimate spatial and temporal trends in catches and abundance of sharks, skates, rays and chimaeras using data from the ISMP database and from the SEF catch and effort database.
3. Identify implications and requirements for species management, fishery bycatch action plans, and FAO IPOA-sharks.
4. Evaluate impact on the ISMP data and catch and effort data collected following adoption of the shark field guide to sharks and rays caught in Australian fisheries.

Final report

ISBN: 978-1-74199-216-8
Author: Terence Walker and Anne Gason
Final Report • 2009-04-14 • 9.92 MB
2001-007-DLD.pdf

Summary

The project met all four objectives completely and the outputs from the project are important inputs for the management of byproduct and bycatch.

Data from the Integrated Scientific Monitoring Program (ISMP) and from fisher logbooks were analysed for the South Eastern Trawl Fishery (SETF) during 1994–06, the Great Australian Bight Trawl Fishery (GABTF), where available, the Gillnet Hook and Trap Fishery (GHATF) during 2000–06. The project delivered several important outputs.

Saw shark and elephant fish assessment and bycatch evaluation in the southern shark fishery

Project number: 1999-103
Project Status:
Completed
Budget expenditure: $189,998.00
Principal Investigator: Terence I. Walker
Organisation: Agriculture Victoria
Project start/end date: 28 Jun 1999 - 9 Jun 2006
Contact:
FRDC
SPECIES

Need

Saw shark and Elephant Fish Investigation

Catches of saw shark rose from 52 tonnes during 1970 to reach a peak of 359 tonnes during 1995 before beginning to decline. Catches of elephant fish rose from 10 tonnes during 1970 to peak at 118 tonnes during 1985 and then declined to 63 tonnes by 1997. These species are currently valued at about $1 million per annum to the fishermen.

Stock assessments of gummy shark and school shark are periodically updated and refined through SharkFAG, but assessments have never been made for any of the non-target species. With the fishery changing to catch quota management and with the need to ensure that the non-target species are harvested sustainably, it is essential to provide basic data needs and assessments for these species.

Because most saw shark is landed in Victoria (90%) and elephant fish is landed in Victoria (64%) and Tasmania (36%), most of the sampling will be undertaken in Bass Strait.

Bycatch and discard evaluation

Over the last decade, national and international attention has increasingly focused on fishing activities that take animals other than those intended for human consumption and other uses. There are concerns that animals might be killed and then discarded and that fishing may be depleting some of these populations.

Public perceptions of discards and bycatches associated with the use of demersal gillnets are often confused with those associated with the use of surface-set driftnets. Whilst it is understood within industry that the discard of dead fish is neglible in the SSF, there is a need to provide better information for the purpose of managing public perceptions.

Effect of high grading/discarding on the TAC setting process

One concern following the introduction of quota management in the SSF is that lower valued gummy sharks and school sharks might be discarded at sea for high grading. Large sharks or sharks damaged by sea lice or other fish often receive lower prices than smaller undamaged sharks. From onboard observations, there is a need to provide estimates of (a) quantities of sharks damaged and marketed, (b) quantities of sharks damaged and discarded, and (c) quantities of undamaged sharks discarded because of lower prices.

Objectives

1. Determine population parameters required for fishery stock assessment of the non-target species common saw shark, southern saw shark and elephant fish.
2. Provide a stock assessment of each of these three non-target species in Bass Strait.
3. Provide data for assessment of bycatch, discards and damaged shark in the Southern Shark Fishery.

Final report

ISBN: 1-74146-416-1
Author: Terence Walker