28 results

Understanding recruitment collapse of juvenile abalone in the Eastern Zone Abalone fishery – development of pre-recruitment monitoring, simulation of recruitment variation and predicting the impact of climate variation

Project number: 2014-010
Project Status:
Completed
Budget expenditure: $141,656.60
Principal Investigator: Craig Mundy
Organisation: University of Tasmania (UTAS)
Project start/end date: 9 Aug 2014 - 31 Jan 2017
Contact:
FRDC

Need

Large fluctuations between years in fishable biomass of abalone are thought to be driven by inter-annual variation in recruitment to the fishery. Over the last decade the changes in recruitment from year to year appear to have been especially extreme which suggests that this may be caused by climate change. Eastern Tasmania is one of the fastest warming parts of Australia as a result of greater extension of the EAC. This possible link between climate change and abalone recruitment can't be investigated in detail at present because of the lack of data / time series on abalone recruitment. This project will establish collection of that data to provide future capability.

When recruitment to the fishery fails, the fishery is reliant on existing older year-classes already in the fishery, leading to a rapid decrease in fishable biomass. The capacity to measure inter-annual variation in sub-legal year-class strength would provide valuable prior warning of decline. Data obtained from a pre-recruit monitoring program will provide fishery-independent data to inform TAC setting. Fishery independent pre-recruit abundance data is a valuable input to the Management Strategy evaluation (MSE) Harvest Strategy and Control Rule system being developed in Tasmania. Application of assessment and MSE (Management Strategy Evaluation) models are both limited due to the absence of data on early year class abundance patterns, and will be improved by access to pre-recruit data.

Objectives

1. Optimise collector module design for quantifying abundance of juvenile abalone across a range of habitat types
2. Determine links between juvenile abundance observed on modules and abalone in surrounding habitat
3. Estimate expected juvenile abundance on collectors in a ‘normal’ recruitment year using published natural mortality data and known abundance.

Final report

ISBN: 978-1-925646-32-0
Authors: Craig Mundy Sarah Pyke Jaime McAllister Hugh Jones
Final Report • 2018-06-25 • 2.80 MB
2014-010-DLD.pdf

Summary

Over the past three decades the Tasmanian Eastern Zone Abalone Fishery has experienced several fluctuations in catch and catch rates of Blacklip Abalone as well as environmental perturbations, which may be affecting productivity. The capacity to measure inter-annual variation in Blacklip Abalone juvenile year-class strength would provide valuable prior warning of decline. Artificial structures referred to as "Abalone Recruitment Modules" were trialled to monitor changes in the abundance of Blacklip Abalone to meet the conditions of the Eastern Zone Abalone Fishery in Tasmania. This requires testing designs in different habitats and improvements to the method of deployment on reef substrates. Work was also required to establish a network of these that is effective in terms of statistical power and operational feasibility.
Industry
Industry
PROJECT NUMBER • 2011-201
PROJECT STATUS:
COMPLETED

Implementing a spatial assessment and decision process to improve fishery management outcomes using geo-referenced diver data

Fishing activity was captured across 53,852 one Hectare hex grid cells across Tasmania. A total of 113,164 diving hours were recorded across 125,536 individual fishing events (Table 1). Between 2012 and 2016, the Tasmanian Geo-Fishery Dependent Data (GFDD) program captured between 85 % and 90 % of...
ORGANISATION:
University of Tasmania (UTAS)
Environment
PROJECT NUMBER • 2015-024
PROJECT STATUS:
CURRENT

Managing ecosystem interactions across differing environments: building flexibility and risk assurance into environmental management strategies

Summary The overarching aim of this research was to provide an improved understanding of the environmental interactions of Atlantic Salmon farming and to provide recommendations to both government and industry on monitoring and management strategies that are appropriate to the level of risk...
ORGANISATION:
University of Tasmania (UTAS)
Environment
PROJECT NUMBER • 2011-087
PROJECT STATUS:
COMPLETED

Tactical Research Fund: trial of an industry implemented, spatially discrete eradication/control program for Centrostephanus rodgersii in Tasmania

The long-spined sea urchin, Centrostephanus rodgersii has expanded its distribution southwards from southern New South Wales, through Eastern Victoria, the Bass Strait Islands and down the east coast of Tasmania. In some areas of Tasmania abundance of C. rodgersii has increased substantially, even...
ORGANISATION:
University of Tasmania (UTAS)
Environment
PROJECT NUMBER • 2015-025
PROJECT STATUS:
COMPLETED

Patterns of interaction between habitat and oceanographic variables affecting the connectivity and productivity of invertebrate fisheries

A better understanding of the links between benthic habitat, oceanography, and fisheries productivity is a major priority of the Blacklip Abalone, Haliotis rubra, and Southern Rock Lobster, Jasus edwardsii, industries to improve sustainable management of these important natural resources. This...
ORGANISATION:
Deakin University Geelong Waterfront Campus
Environment
PROJECT NUMBER • 2013-026
PROJECT STATUS:
COMPLETED

Can commercial harvest of long-spined sea urchins reduce the impact of urchin grazing on abalone and lobster fisheries?

At low-levels of exploitation, commercial harvesting of long-spined sea urchins was found to prevent increase in urchin density. Adjacent unfished locations experienced an increase in both urchin density and grazed area over the 2014 – 2016 study period. Research sampling of populations...
ORGANISATION:
University of Tasmania (UTAS)
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