2 results

Indicators for density and biomass of exploitable abalone – developing and applying a new approach

Project number: 2020-065
Project Status:
Current
Budget expenditure: $147,900.00
Principal Investigator: Keith Sainsbury
Organisation: Western Abalone Divers Association (WADA)
Project start/end date: 30 Nov 2020 - 30 May 2022
Contact:
FRDC
TAGS
Survey
Stock Assessment
Resource Access And Allocation
Fishing Gear
Fishing Effort
SPECIES
Blacklip Abalone
Greenlip Abalone
Brownlip Abalone

Need

Most jurisdictions have developed and used various combinations of indicators in stock assessment and TAC setting of their abalone fishery. Applications often use a time series of commercial catch rate or FIS density to detect trends and identify reference points of stock status. The use of fishery dependent indicators from logbooks and GPS loggers have been criticized for their potential to be biased and insensitive (‘hyper-stable’) because of commercial selection of all observations that are made. As a consequence, Fishery Independent Surveys (FIS) have also been used in stock assessment, with varying coverage in all state’s abalone fisheries. However, FIS have also been criticized for their large cost and considerable uncertainty about how representative and useful the data is for intensely spatially-structured abalone fisheries (e.g. spatial mismatch of the FIS and the stock). FIS reviews in several states found variable relationships between FIS estimates and other indicators of the fishery.

Alternatively, both GPS loggers and FIS have considerable complementary strengths. GPS logger information has strengths of extensive fine-scale detail about catch (e.g. allowing spatial standardisation, that represents one of the main challenges to fishery dependent data) with good coverage of the fishery, while FIS have strengths of repeatable and local scale detail that is independent of the fishery.

The project will review data available from GPS loggers, catch records and FIS in WZ Victoria, with possible extension to other fisheries depending on data access and funding. Methods to calculate density and biomass from different sources of data will be consolidated and applied at different spatial scales, and the precision and statistical coherence of estimates compared. These comparisons will enable the development of criteria to improve design of FIS, logger programs and related observations, and recommendations and guidance on the use of indicators of legal density and biomass in fishery harvest strategies.

Objectives

1. Use the Victorian Western Zone (and other fisheries data, where available) as a test-bed to develop and evaluate a new approach to calculating density and biomass indicators of exploitable abalone.
2. Consolidate methods to calculate indicators of local exploitable density from reported catch, GPS logger and fixed site survey observations.
3. Assess the consistency, accuracy and reliability of these new indicators, and their likely performance for management decisions
4. Develop and apply new methods to (i) calibrate logger-derived local density from overlap of local observations of loggers and surveys, (ii) use logger observations to estimate the area fished and to which the calibrated local density estimates could be extrapolated to apply, and (iii) combine the density and area estimates to give an index of exploitable biomass in the fished area.
5. Provide criteria for the design of surveys, logger programs and related observations (e.g. the spatial scale of catch reporting) to give calibrated logger density and biomass indicators.
6. Provide recommendations and guidance on the use of indicators of exploitable density and biomass in fishery harvest strategies.
7. Provide training to develop capacity to understand and implement the approach with logger data.

Report

Authors: Keith Sainsbury Duncan Worthington and Bill Venables
Report • 2023-05-10 • 2.69 MB
2020-065 interim progress report.pdf

Summary

The objectives of this project are to use the Victorian Western Zone (WZ) abalone fishery to develop and evaluate a new approach to calculating abalone density and biomass indicators from the combination of three information sources. The three information sources are:
   i.   Logbook reported catch and effort,
   ii.  Global Positioning System (GPS) logger records plus depth and catch from fishers, and
   iii. Fishery Independent Survey (FIS) observations collected by the government Victoria Fisheries Authority (VFA) and surveys done by the Western Abalone Divers Association (WADA).
 
This document provides a update on project progress to date, which has been mostly on reconciling the input data and replicating the analyses that were done historically to recommend a Total Allowable Commercial Catch (TACC) for the fishery.

National Abalone Diver Exchange Program

Project number: 2018-109
Project Status:
Completed
Budget expenditure: $4,800.00
Principal Investigator: Craig Fox
Organisation: Western Abalone Divers Association (WADA)
Project start/end date: 31 Aug 2019 - 31 Aug 2021
Contact:
FRDC
TAGS
Wellbeing
Stakeholder
Marketing
Harvest Strategy
Fishing Effort
SPECIES
Abalone

Need

This project will provide for the first time, a platform for abalone divers to come together from different jurisdictions and exchange their wealth of knowledge, skills, and best practices with each other for the benefit of the Australian abalone industry. In addition to the objective of improving practices and building industry capacity and resilience, the project will also provide the opportunities for divers to network, build relationships, exchange ideas, and work toward other joint ventures.

While the Australian abalone industry is a highly collaborative fishing sector through industry peak bodies and associations, there is little-to-no interaction between divers across jurisdictions. Divers in the abalone industry historically do not necessarily have a voice or a mechanism to come together, to discuss and share their issues, their knowledge, operational skills and best practices. Yet divers are the custodians of the resource, are the eyes under the waters, and have extensive knowledge and expertise to share.

Given the current state of the industry and issues faced - for example strict quotas, descending TACCs, safety concerns, biosecurity concerns, increasing shark populations, environmental change, market fluctuations and opportunities, an aging industry - it is now critical for abalone divers to come together and exchange their knowledge for the benefit of all stakeholders in the Australian abalone industry and the fishery.

Each jurisdiction has its own strengths and weaknesses. For example, Victoria is a leader in industry-led data collection and safety, Tasmania leads on value-adding to the product, and Western Australia is current leaders in shark mitigation. The purpose of the project is to share these strengths with each other. The project will also utilise industry expertise and contacts in key strength areas. For example, fisheries scientists, health practitioners, processing and marketing sectors.

The most important part of this project is that it is diver-led, which will ensure industry participation, and that it will contain relevant and appropriate content for divers.

Objectives

1. To facilitate improved knowledge exchange between Australian abalone divers across jurisdictions
2. To build collaboration and exchange knowledge between divers, experts, and stakeholders across all abalone fishing jurisdictions
3. To deliver appropriate dissemination materials which are accessible to all Australian abalone divers
4. To review the AWA® Quality Assurance Code of Practice
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