8 results

Estimating fishing mortality of major target species and species of conservation interest in the Queensland east coast shark fishery

Project number: 2010-006
Project Status:
Completed
Budget expenditure: $402,174.00
Principal Investigator: Andrew & Renae Tobin
Organisation: James Cook University (JCU)
Project start/end date: 30 Jun 2010 - 29 Jun 2013
Contact:
FRDC

Need

Shark fisheries worldwide are extremely valuable economically though are universally threatened through a combination of high susceptibility to depletion, poor data on levels of fisheries exploitation and uncertainty about what are appropriate levels of exploitation. These facts hold true for the Queensland east coast shark fishery as a high diversity of shark species are harvested through a complex combination of targeted and non-targeted fishing effort spread throughout 18 degrees of latitude. The current data void prevents effectual management, assessment and monitoring; problems well documented by the recent Gunn et al (2008) review of proposed management measures for the Queensland fishery completed for the Hon Peter Garrett MP, Minister for the Environment, Heritage and the Arts. The Gunn et al (2008) review put forward 14 conditions and 8 recommendations, most pertinent being to determine exploitation and mortality rates, and improve the understanding of the shark complex with which the fishery interacts through improved reporting, observing and validation.

Significant changes in the management of the Queensland fishery began on 1 July 2009 and include substantial changes including modifications in the way commercial fishers are permitted to harvest shark stocks, as well as improved catch reporting. The need to move forward quickly in gathering information relevant to sustainable use of Queensland sharks is paramount. The Gunn et al 2008 report concluded that on the basis of the poor coverage of some, and complete absence of other data vital for confident management, the proposed management arrangements for the fishery were insufficiently cautious. The proposed project will directly address not only these concerns, but also the key research priorities relevant to shark identified by the Queensland FRAB.

Gunn, J, Meere, F, Stevens, J (2008). Independent review proposed manage,ment arrangements for Queensland’s east coast Inshore Fin Fish Fishery.

Objectives

1. Estimate fishing related mortality of major target species and species of conservation interest.
2. Utilising the recapture data provided through objective 1, broad scale movement patterns as well as in situ growth rates will be estimated.

Final report

ISBN: 978-0-9941500-4-2
Author: Andrew Tobin
Final Report • 2015-08-18 • 3.01 MB
2010-006-DLD.pdf

Summary

Fishing mortality rates for the major targeted and byproduct species of sharks landed by the Queensland East Coast Inshore Fin Fish Fishery (ECIFFF) have been estimated. The effects of these fishing mortality rates on population persistence for these species have also been modelled with demographic analyses to predict future population trends.
The Centre for Sustainable Tropical Fisheries and Aquaculture has completed this project in response to increasing interest and concern by all stakeholders around the status of shark populations exposed to the fishing activities of the Queensland ECIFFF. A large-scale tag-recapture project was completed across 2010 and 2011 and provided the relevant data to complete this exercise. A total of five tagged shark species realised a total of 324 recaptures.
We found that current fishing mortality rates appear generally sustainable. Robust fishing mortality estimates and subsequent demographic modelling outcomes were possible for four of the most dominant species harvested by the fishery – the undifferentiated blacktip shark (Carcharhinus tilstoni/limbatus) complex, spot tail shark (C. sorrah), spinner shark (C. brevipeenna) and pigeye shark (C. ambionensis). For all species except pigeye sharks fishing mortality rates were found to be low to moderate, but likely within sustainable bounds. For the pigeye shark, fishing mortality estimates were relatively high with several methods indicating harvest rates may have been unsustainable. Less robust estimates of fishing mortality were achieved for an additional six species including milk and sharpnose sharks Rhizoprionodon acutus and R. taylori; creek whaler C. fitzroyensis; bull shark C. leucas; and the scalloped and great hammerheads Sphyrna lewini and S. mokarran. For these species estimates are likely highly imprecise and should be used cautiously.
Industry
PROJECT NUMBER • 2003-060
PROJECT STATUS:
COMPLETED

Byproduct: Catch, economics and co-occurrence in Australias longline fisheries

The longline sector of the Eastern Tuna and Billfish Fishery (ETBF) and the Southern and Western Tuna and Billfish Fishery (SWTBF) target four main species and incidentally take over 80 other species as “bycatch”. Significant amounts of these species are often retained for sale, and...
ORGANISATION:
Department of Agriculture, Fisheries and Forestry (DAFF) ABARES

A pilot investigation of northern shark liver oils: characterisation and value-adding

Project number: 1999-369
Project Status:
Completed
Budget expenditure: $35,846.47
Principal Investigator: Peter D. Nichols
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 6 Sep 1999 - 24 Mar 2002
Contact:
FRDC

Need

To maximise the return to fishers and wider areas of the Australian fishing industry better use of existing resources is needed. Southern fisheries have recently seen development of several marine oil based products. The potential may exist for a similar approach with northern fisheries, in this case specifically northern sharks.

Presently there is to our knowledge little information available on the oil composition of the livers from northern sharks. A prerequisite therefore in the consideration of the development of possible marine oil products is the characterisation of the oil resource. The proposed pilot project aims to address this key need. The proposed research aims to assist the fishing industry maximise the return on northern and other shark species at whatever levels are determined to be sustainable.

Objectives

1. Characterise liver oils from northern sharks (NT, WA, Qld), including examining possible changes with location, season and other factors. The key components to be examined will be the omega-3 PUFA and vitamins.
2. Provide initial comment on the potential commercial usefulness of the liver oils from northern sharks.

Final report

ISBN: 1-876-996-05-6
Authors: Peter Nichols Mark Rayner and John Stevens
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