Mitigation measures to reduce entanglements of migrating whales with commercial fishing gear
National application of sustainability indicators for Australian fisheries
The urgency to develop a comprehensive and practical reporting system has increased substantially in recent years. The requirement for assessments include the need for third party Government Auditing that will result from the proposals by Environment Australia (EA) to amend schedule 4 of the Wildlife Protection (REI) Act (1982) along with the imminent introduction of the Environment Protection and Biodiversity Conservation Act in July 2000 and the implementation of the Oceans Policy strategies. There are also requirements within each jurisdiction to meet general government commitments to ESD and particularly when these are explicitly part of their Fisheries Legislation. Finally there are also recent developments associated with industry wanting to either gain market access or provide increased leverage for their products from gaining environmental accreditation. Thus, there are a large number of reasons why assessments need to be completed. There is an even greater need to ensure that the reporting schemes developed are sufficiently comprehensive to restrict the level of duplication.
The Standing Committee on Fisheries and Aquaculture (SCFA) identified the need to actively progress the development of nationally agreed criteria and indicators that would enable fisheries managers to report against all the principles of ecologically sustainable development (ESD). The ESD objective is now explicitly or implicitly part of State and Commonwealth fisheries management legislation. There are a number of components related to ESD within the fisheries context, these include the target species, the ecosystem, social and economic issues and also management arrangements. Not all of these components are of interest or are addressed in each of the identified requirements listed above. Thus, in the assessments required by Environment Australia the only components addressed are the target species, the ecosystem and management arrangements. This is similar to the assessments required under the Marine Stewardship Council. Assessments for ISO 14000 and Codes of Conduct only cover management arrangements. However, to fully meet the commitment to ESD, all components will need to be assessed. Consequently the proposed SCFA process will cover all aspects of ESD. These comprehensive assessments should nonetheless incorporate the aspects required for these other requirements.
The SCFA Working Group has been established to steer the development of ESD criteria and indicators with the support of the SCFA Research Committee, who have developed a system for ESD reporting. The Working Group has agreed on an approach and timetable that would result in a report on the application of nationally agreed criteria and indicators for all Australian fisheries by mid 2001.
The Working Group approach includes 3 key research tasks that support their objectives, which require funding:
1. Application of draft criteria and framework using case studies
2. An SCFA workshop based around the case studies
3. An “Initial National Application” report of the ESD criteria and indicators for Australian fisheries
The urgency to progress this approach was raised at the ESD Stakeholder Workshop that was held in Geelong during March 2000. All stakeholder groups were represented at this workshop and they all recognised that there was a strong need to progress from the current situation to one where reporting on all components of ESD can be completed.
Endorsement was obtained from all sectors for the SCFA approach. There were, however, clear indications that effective consultation and participation from stakeholders were required during the project to ensure that the results will obtain national recognition and support. Consequently, a Reference Group will be established that will include representatives from Environment Australia, Commercial Fisheries, Aquaculture, Recreational fisheries, Indigenous groups, FRDC, Environmental groups and other relevant experts. The Reference Group would work in partnership with the SCFA Working Group to assist in the coordination and exchange of information. It was also suggested that this Reference Group along with selected memebrs of the SCFA Working Group could act as a resource for other relevant ESD projects (e.g. 2000/358).
Finally, the workshop resulted in the development of the appropriate linkages between the members of the SCFA proposal, which is primarily concerned with the development of effective ESD reporting mechanisms, with the proponents of the other ESD projects such as FRDC 2000/358 which is designed to assist industry develop better, more environmentally credible methods of operation. These discussions resulted in the agreement as to how the two projects can benefit each other.
Case study
Mother-of-pearl (Pinctada maxima) shell: stock evaluation for management and future harvesting in Western Australia
Modelling to explore management strategies to optimise the value of the rock lobster fishery of Western Australia
It is recognised by industry that the yield currently obtained from the western rock lobster fishery cannot be enhanced by increasing exploitation without also reducing the breeding stock to an unacceptable level. The value of the fishery can only be increased by reducing costs or by increasing the value of the catch. Modelling of the fishery is required to investigate the potential improvement in value that might be obtained from an optimal set of management controls designed to improve market prices through controlling the supply of lobsters to the market both within and among fishing seasons. The ability to predict future catches based on puerulus settlement indices offers the rock lobster industry in Western Australia a unique opportunity to improve prices by varying the exploitation rate between seasons in order to more closely match market demand.
A modelling project to address this need will require the development of a more statistically sound model of the lobster fishery than was provided by the descriptive model developed by Walters et al. (1993). This will benefit the participants in the fishery by providing an understanding of the uncertainties associated with model predictions, and the validity of the new model when applied to different sectors of the fishery. The earlier model used information from only a small subset of the data available from the fishery, and the new model will utilise far more of the available data, thus providing a more robust description of the rock lobster fishery.
Development of the proposed model is seen as an essential and strategic element of the research programme for this fishery.
Final report
The fishery for the western rock lobster (Panulirus cygnus) is Western Australia’s most important single species fishery, and yields an average annual catch of 10,500 to 11,000 tonnes valued at between $200 and $300 million at the point of landing. With a high level of exploitation and a product with a high export value, the need was recognised for the development of appropriate models to evaluate alternative management strategies. This study describes the models that were developed.
A number of outcomes of the study may be identified. A size-structured model was developed for the P. cygnus fishery. The monthly growth transition matrices required for this model were estimated from tagging data. Data on beach prices received for lobster and costs of bait, fuel, gear and crew were collected for 1998/99. Examples of the use of the size-structured model to explore alternative management strategies, and the results of a calculation of the net relative value of the catch estimated by the size-structured model are presented. The relationship between vulnerability and carapace length of the lobsters was investigated, and the concentration of fishing effort on locations and depths where the smaller lobsters are located was found to be a major factor affecting the size composition of the catch. An age-structured model of the fishery was also developed. This model was used to investigate the effect of the management changes introduced to the fishery in 1993/94. An example of the use of this age-structured model to explore the consequences of an alternative management strategy and the uncertainty of the resulting estimates of egg production under the alternative strategies was presented.
Keywords: lobster, model, stock assessment, economics