Assessing the impact of marine seismic surveys on southeast Australian scallop and lobster fisheries
Social Science and Economics Research Coordination Program (SSERCP)
SCRC: Measuring condition of lobsters to improve management of harvesting around periods of high transport mortality
Annual losses of up to 10% of lobsters during live transport are not uncommon and have a major financial impact. The fishing industry, including processors and operators are seeking ways to avoid this mortality. As deep-water pale lobsters are more susceptible to this mortality, this project will examine their wild physiological condition in great detail and compare it to shallow-water red lobsters.
Mortality events occur mainly around the time of season openings in Mid November so this will the period targeted in this research. Price often falls sharply at this time because of the combined effect of increase in supply and damage to market reputation that occurs when impacted shipments are received. Managing the landing of poor quality lobsters has always been difficult because longer closed seasons would prevent landing of poor quality product but also harms businesses.
Ideally the problem of lobster mortality in shipment would be managed by keeping the fishery open for extended periods but only landing lobsters when their condition is acceptable. The fishery tends to do this on a crude level by discounting the price of pale lobster. However this is not ideal because it impacts the price of some catches of pale lobsters that are good condition, and also allows the shipment of some red lobsters of poor condition. Directly measuring condition is a step towards better management of this issue.
Final report
This project provides the first comprehensive quantitative assessment of the health, physiological and nutritional condition of brindle and red lobsters from four different fishing areas of Tasmania at the start of the 2015 fishing season. Lobsters size (carapace length), baseline concentrations of haemolymph haemocyanin and bicarbonate were shown to be useful predictors of vulnerability to transport.
This information may help improve the management of these lobsters especially if portable meters are used in the field or test kits are developed through future R&D. Recommendations to minimise mortality risk were also made which included ensuring lobsters have recovered from the ground transport stress in holding tanks for several days, minimising emersion duration and reducing temperature prior to packaging.
Building economic capability to improve the management of marine resources in Australia
Ensuring monitoring and management of bycatch in Southern Rock Lobster fisheries is best practice
Rock Lobster Enhancement and Aquaculture Subprogram: preliminary investigation towards ongrowing puerulus to enhance rock lobster stocks while providing animals for commercial culture
Development of a rock lobster aquaculture industry through the harvest of puerulus from the wild cannot proceed if there is a net loss of animals from the wild fishery. The concept of removing puerulus from the wild has received widespread opposition from participants in rock lobster fishing industries, and managers of the resource, as the resource is considered to be highly exploited. Rock lobster fisheries management policy in most states is specifically directed towards stock rebuilding and it is perceived that additional extraction by puerulus removal runs counter to those policies.
Current research on techniques for the extraction and on-growing of puerulus from the wild have proceeded with an assumption that puerulus extraction should be "biologically neutral". It has been proposed that "biological neutrality" can be achieved by a proportional reduction in catch of adult animals, either through a reduction in effort (eg removal of pots) or through buy-out of quota (in ITQ management). However, this mechanism for achieving biological neutrality has been criticised, as puerulus extraction is likely to occur in sheltered, heavily exploited regions - while the effort removed from the fishery may have been directed to a completely different region. In this scenario, puerulus extraction could lead to local depletion and loss of egg production, despite the concurrent reduction in effort.
The proposed project is directed to an alternative mechanism for compensating for the removal of puerulus. Reseeded animals can be released back to the same areas from which they were extracted so no localised depletion will result. Reseeding the area with animals additional to those required for biological neutrality will provide an enhancement benefit. This system has benefits to the fishing industry through enhanced yield, and also to the proposed aquaculture industry through access.
The potentially valuable on-growing industry is reliant upon the development of a mechanism for compensating for puerulus loss that does not harm the wild fishery.