Physical oceanographic influences on Queensland reef fish and scallops

Project number: 2013-020

Project Status:

Completed

Budget expenditure: $170,000.00

Principal Investigator: Tony J. Courtney

Organisation: Department of Agriculture and Fisheries EcoScience Precinct

Project start/end date: 23 Jun 2013 - 29 Mar 2015

Contact:

FRDC

Need

There is a strong need for Queensland fishery managers to obtain a better understanding of key physical oceanographic influences on target species of commercial and recreational fisheries.

Tropical cyclones have been associated with reef fish catch rates. Coral trout (Plectropomus leopardus) catch rates typically fall after a major cyclone, while those of red throat emperor (Lethrinus miniatus) rise (see “Background” above). The effects on catchability can last several years. While the exact causal mechanism is not known, it is thought to be related to water temperature.

Nutrient-rich cold water eddies, which break from the East Australian Current and move westward onto the Queensland continental shelf are likely to affect the spat settlement, growth, abundance and catch rates of saucer scallop (Amusium balloti). Understanding these relationships may lead to improved management, assessment and forecasting of catch in these fisheries, and it may also lead to improved acceptance of quantitative stock assessment results by industry.

This proposal differs from previous abiotic studies because it focuses more on offshore, oceanic influences, rather than coastal rainfall and flow data.

Objectives

1. Review recent advances in the study of physical oceanographic influences on fisheries catch data, and describe the major physical oceanographic features that are likely to influence Queensland reef fish and saucer scallops.

2. Collate Queensland’s physical oceanographic data and fisheries (i.e., reef fish and saucer scallops) data.

3. Develop stochastic population models for reef fish and saucer scallops, which can link physical oceanographic features (e.g., sea surface temperature anomalies ) to catch rates, biological parameters (e.g., growth, reproduction, natural mortality) and ecological aspects (e.g. spatial distribution).