Conflicts between LCF gill net fishers and Long-nosed Fur Seals have escalated in recent years with the reported level of fur seal depredation of caught fish from, and damage to, gill nets now jeopardising the economic viability of the fishery. Representatives from the LCF estimate that fur seal depredation has reduced fishery production by approximately 25%. In 2012/13, a commercial LCF licence holder documented production losses of $76,000 over a 5 month period. At the same time, 19 other licence holders were experiencing similar or greater losses. Industry estimates that fur seal interactions are costing the fishery a wharf value loss of $2 million. Industry now questions whether the fishery will be viable in five years if alternative management strategies or options are not found to mitigate the impacts of interactions.

The need for alternative fishing methods and/or deterrent systems to reduce the impacts of fur seal depredation on the fishery is urgent, given the increasing economic impacts to the LCF fishers and the local communities that rely heavily on the fishing industry.

Management and mitigation of the bycatch of protected species is required under the EPBC Act and the Fisheries Act. Bycatch trigger limits provide a framework to manage marine mammal bycatch rates and are used by AFMA in the management of the SPF and in the gillnet sector of the Southern and Eastern Scalefish and Shark Fishery (SESSF). The setting of trigger limits requires quantitative information on population size to ensure that the impact of fishing mortality does not negatively affect population status.

Robust population estimates do not exist for most marine mammal species in Australian waters and are particularly limited for cetaceans and there is also limited to no information on the distribution and population structure of these species. Bycatch trigger limits need to consider the smallest population unit to ensure that levels of anthropogenic mortality are sustainable.

Where data are sparse, it can be difficult to reach consensus between different stakeholder groups on the validity of management measures, particularly in relation to trigger limits. By eliciting expert knowledge through a formally structured system, a transparent process of evaluating and synthesising current data and quantifying the uncertainty around proposed bycatch trigger limits is available for managers and can be used to build industry and stakeholder support. This is particularly important when considering the management of bycatch impacts on populations that interact with a number of different jurisdictions.