Developing and applying a spatially-based seascape analysis (the "habitat proxy" method) to inform management of gulper sharks: Compendium of CSIRO Discussion Papers

Environmental Management;Natural Resource Management

Williams, Alan ; Althaus, Franzis ; Smith, Tony ; Daley, Ross ; Barker, Bruce ; Fuller, Mike

CSIRO Marine and Atmospheric Research

DOI  :  10.4225/08/584c43b5904ed
RP-ID  :  EP131328

学科分类：地球科学(综合)

澳大利亚|英语

来源: CSIRO Research Publications Repository

【 摘 要 】

This document is a compendium of 10 Discussion Papers provided from a CSIRO project to help develop additional management options for Harrisson’s Dogfish and Southern Dogfish within AFMA’s Upper Slope Dogfish Management Strategy (USDMS). The Discussion Papers were presented and reviewed during a series of stakeholder meetings, and with input by an independent Gulper Shark Scientific Working Group, between October 2011 and July 2012.Collectively, the papers provide a synthesis of ecological information for the upper slope seascape off southern and eastern Australia which is the habitat of these two shark species.The aim of the research is to inform decisions about management measures taking into account a range of objectives.The form of this ‘compendium’ report is a set of 6 chapters summarising the scope and contributions of the various research outputs.The role of this summary is to help navigate through the research outputs, rather than to provide a summary of the outcomes or uptake of the results.1. Identifying candidate areas for gulper shark conservation•Updates knowledge of species ranges (along-slope and depth)•Explains methods and visualises data for screening and identifying Candidate Areas for enhancing the fishery closed area network •Summarises the recent (2006-2010) spatial distribution of commercial effort and catch as an indication of economic value in Candidate Areas2. Identifying options for spatial closures •Identifies options for spatial closures using an MSE approach •Contrasts trade-offs for conservation and socioeconomic objectives•Evaluates the collective properties of sets of Area Options as a network•Describes the pre-existing 700 m trawl closure in relation to the gulper shark habitat distribution and details its potential efficacy for gulper shark habitat protection•Details the available information for the western GAB in regard to Southern Dogfish and details the fisheries closures and proposed CMRs in that region3. Identification and area tally of fishery closures and other managed areas •Tabulates areas of existing and proposed closures•Classifies management arrangements for individual closures•Summarises considerations to evaluate relative efficacy of each class (‘weighting’)•In respect to the Flinders Research Zone, comments are made on regulation of fishing in managed areas that are not fully closed to fishing 4. Estimated depletion of Harrisson’s and Southern Dogfish•Amalgamates 3 documents presented at various stages of the consultation process •Estimates pre-fishing carrying capacity over the ranges of the shark populations•Estimates sub-regional depletion of gulper shark populations due to fishing5. Additional information on survival and mitigation methods•Documents existing information on capture and post-capture survival from auto-longline fishing based on recent survey and observer data•Documents diel distribution of gulper sharks and discussion of the potential efficacy of night-time bans to fishing •Discusses potential effectiveness of non-spatial mitigation methods such as e-monitoring and codes of conduct.6. Metrics indicating the recovery potential represented by areas under management or being considered for management•Chapter added after July 2012, in preparation for the TSSC meeting in November 2012•Presents four metrics that may be used to assess the relative potential for gulper recovery, applying results from Chapters 34:1.Plan area 2.Estimated carrying capacity of an individual area or area type3.Fraction of the total current population that remains in an individual area or area type4.Potential increase in population in an individual area or area type •Tabulates these metrics for existing and proposed closures