Options for Tier 5 approaches in the SESSF and identification of when data support for harvest strategies are inappropriate

Project number: 2013-202
Project Status:
Completed
Budget expenditure: $114,154.00
Principal Investigator: Malcolm Haddon
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 30 Jun 2013 - 29 Jul 2014
Contact:
FRDC

Need

The current Harvest Strategy Framework has no formal process for deciding whether the Tier harvest strategy applied to a stock is appropriate or not, there is thus no formal process for deciding when to use a lower Tier. Even worse, when a Tier4 assessment is deemed inappropriate in the SESSF there is no lower Tier available for use. There is thus a need to establish guidelines for identifying when a Tier method is inappropriate for a stock, and also a need to develop an array of alternative harvest strategies for use as a Tier5 when Tier4 is deemed inappropriate. As there is such a wide range of potential Tier 5 procedures, many with the same data requirements, testing is required to allow an informed decision about which are best to implement - particularly in the SESSF context.

Section 6 of the DAFF public discussion paper for the review of the Commonwealth fisheries Harvest Strategy Policy (see FRDC project 2012/225) investigates questions of uncertainty about assessment approaches, the level of data required to maintain species within a given Tier and when to switch between Tiers. The proposed project directly addresses known issues in the SESSF that relate to this question, and timing of the review allows this project to tailor analyses to specifically address review recommendations and advice.

A parallel and complementary project (FRDC 2012/202) provides a study of the trade-off among ecological and economic risks associated with harvesting, the benefits of harvesting and the costs associated with management. This is concerned with strategic considerations over all Tiers, whereas the current project looks more specifically at data requirements within SESSF Tiers, and alternative Tier procedures for data poor species in the SESSF.

Objectives

1. Establish guidelines, using SESSF case studies, for when the particular Tier harvest strategy for a given stock becomes inappropriate and make explicit recommendations as to what response would then be appropriate.
2. Determine options for alternative harvest strategies when none of the present Tiers is appropriate (i.e. potential Tier 5 approaches)
3. Produce presentations and explanatory documents for distribution across RAGs and MACs, describing the criteria and new Tier 5 harvest strategies.

Final report

ISBN: 978-1-4863-0493-6 (print.)
Author: Malcolm Haddon

Related research

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Environment
Environment

Re-assessing giant crab (Pseudocarcinas gigas) size limits to optimise value and sustainability of the fishery

Project number: 2006-022
Project Status:
Completed
Budget expenditure: $49,983.01
Principal Investigator: Caleb Gardner
Organisation: University of Tasmania (UTAS)
Project start/end date: 29 Sep 2006 - 30 Oct 2008
Contact:
FRDC
SPECIES

Need

Inappropriate fishery regulations can harm fisheries by unnecessarily retarding stock rebuilding. While the initial setting of size limits in the giant crab fishery was based on the precautionary principle and the best available data, the market preference for small crabs was not anticipated and therefore not considered when size limits were set. Any changes to fishery controls, particularly in a fishery where catch rates appear to be stabilising, must be approached with caution. Given that the emphasis of size limits has, appropriately, been on preserving the fertility of crab stocks, it would be inappropriate to adjust size limits without first re-evaluating the reproductive status of the population. This is particularly important as we know that the way the fishery is currently structured has resulted in an unbalanced harvesting of males and females. Biological data gathered during this process will significantly improve the predictive capability of the assessment model with respect to egg production.

This proposal addresses three of the 12 research and development priorities for wild fisheries outlined in the Tasmanian Fisheries and Aquaculture Research Strategic Plan (2005-2008). It addresses the priority 'Management options/assessment' by seeking to optimise management measures for the giant crab fishery, the priority of 'Resource assessment & monitoring' by providing information on the current reproductive status of the giant crab population, and the priority area 'impacts of fishing' by comparing current reproductive parameters with that of the population prior to the rapid expansion of this fishery.

Objectives

1. Describe the reproductive status of the fished giant crab population and compare it to that of the virgin population.
2. Assess the implications of changes in current size limits, and document options that best balance the aims of optimising value while rebuilding stocks.

Final report

ISBN: 978-1-86295-543-1
Author: Caleb Gardner