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Title:

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

Project Number:

2015-025

Organisation:

Deakin University Geelong Waterfront Campus

Principal Investigator:

Daniel Ierodiaconou

Project Status:

Completed

FRDC Expenditure:

$270,000.00

Program(s):

Communities, Environment, Industry

Need

This study will provide a better understanding of the importance of scale relationships between benthic habitat, oceanography, and biology and their independent and interactive impact on larval dispersal, settlement and productivity in the Victorian blacklip abalone Haliotis rubra, and southern rock lobster Jasus edwardsii fisheries. Understanding the scale of these relationships is critical for spatial management in determining the sharing of responsibility between Government as the regulator and Industry as the lead for the implementation of voluntary and appropriately scaled management strategies. Population dynamics, habitat availability, complexity, and physiography determining dispersal, settlement, survivorship and growth need to be considered in order to understand the primary drivers of productivity on local geographical scales, and the resilience of fishing stocks to fishing pressure and threats associated with environmental change, including pests and disease. Importantly, and pertinent to species such as southern rock lobster with prolonged planktonic larval phases, understanding these dynamics on broad spatial and temporal scales will assist in determining the dependency of Victorian fisheries on interstate recruitment sources. These factors will be explored using a multidisciplinary approach involving geospatial, oceanographic and biophysical modelling, and genomic technologies providing industry with a framework for guiding future management decisions. Outputs from this study will provide industry with data and guidelines for assessing the resilience or vulnerabilities of specific fishing stocks to overharvesting or environmental disturbance, and the potential for natural replenishment in the event of stock depletion. Ultimately this will help guide where stock restoration and enhancement activities are needed to catalyse recovery, or where reef closures may be beneficial for recovery.

Objectives

1. Integrate commercial catch and survey data with LiDAR-derived seafloor structure information to identify the spatial structure and patch-level productivity of reef systems,potential abalone fishable habitat extent and map important source reefs of abalone larvae.

2. Development of a high resolution hydrodynamic model for Victorian coastal waters that allows the modeling of larval dispersal between individual reef complexes throughout state waters.

3. Development of a biophysical larval dispersal model to map the probable dispersal pathways for H. rubra and SRL across Victorian reef complexes.

4. Determine if recruitment across the respective fisheries is influenced by adaptive genetic factors.

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

Final Report
ISBN:978-0-7300-0140-9
ISSN:
Author(s):Daniel Ierodiaconou
Date Published:January 2019
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 study aimed to quantify and map the influence of benthic habitat characteristics, oceanography, and biology on larval dispersal, settlement and productivity of Blacklip Abalone and Southern Rock Lobster for Victorian fisheries.
This study provides industry with substantial long-term benefits relating to assessments of stock viability and implementation of management strategies that optimise sustainable yield primarily through the identification of important larval source reefs, dominant dispersal pathways and the role of genomic selection on population recruitment processes. Improved understanding of relationships between stock productivity and environment is supported by a repository of high-resolution maps of coastal habitat overlaid with oceanographic and biological factors that influence population structure and fisheries productivity for Abalone and Southern Rock Lobster.