Postgraduate Profiles

Michael Brooker

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Thesis: An investigation into a suspected area of low catch rates of Western Rock Lobster (Panulirus cygnus) in an area of historically high catch in the centre of the fishery.

The western rock lobster (Panulirus cygnus), endemic to Western Australia, is the target of Western Australia’s most valuable commercial fishery. The Department of Primary Industries and Regional Development Fisheries Directorate (Fisheries) utilizes long-term monitoring of puerulus settlement rates, established in the 1960’s, to manage this fishery. In response to low settlement rates in 2008, Fisheries introduced management changes to reduce fishing effort and a shift to quota management in 2010. This resulted in record low harvest rates and high biomass levels across the fishery. However, in the shallow areas (less than 20metres) near the centre of the fishery where sub-adult abundance is expected to be highest, it is suspected that catch rates have become increasingly lower than historical catches.

In collaboration with DoF, my project will utilize a variety of fisheries dependent and independent methods including puerulus collectors, modified lobster traps, remote underwater video and diver surveys, to investigate the population dynamics of puerulus, post-puerulus and sub-adult western rock lobster in this region. I will investigate the habitat associations and potential preference of juvenile rock lobster for habitats across the region.

Why my research is important

The western rock lobster along with many other species of lobster from the family Palinuridae are the subject of highly valued fisheries around the world. The western rock lobster is endemic to Western Australia, is the target of Western Australia’s most valuable single species wild caught commercial fishery, worth around $400 million dollars per annum.

Given the significant value of the fishery, it is important to increase our understanding of the suspected area of reduced catches as this could impact the productivity of the fishery and could expand in the longer term, threatening the overall sustainability of the fishery. A greater understanding will also assist in the future management and adaptation of the fishery to ensure the continued productivity.

Funding

A juvenile western rock lobster.

Aug 2017

Aug 2020

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