ASFB workshop: towards sustainability for data limited multi-sector fisheries
The current ESD case studies project has identified multi-sector fisheries, often with limited data, as posing one of the most difficult areas for assessment of stock status. These fisheries are typically fished by a small number of commercial operators taking small catches of a diverse range of species. Comprehensive commercial databases are generally lacking, and recreational catches are poorly known. Such stocks are often significantly impacted by environmental variation both man made and natural.
There is an urgent need for researchers and managers responsible for future fisheries ESD reporting and assessment to examine techniques for data gathering (both catch/effort and biological) and assessment for these types of fisheries. The historical approach of dealing with the data and assessments of fisheries from a single sector perspective is no longer compatible with ESD requirements.
This ASFB workshop will bring scientists, managers, and other stakeholders together to investigate innovative ways of providing reliable assessments of the stocks and sustainable harvest levels for our coastal, estuarine, and inland fish resources.
Final report
Despite the collapse of Ansett, and travel bans by US government employees, 69 delegates attended. All papers were presented, albeit some not by the author, with the written papers and discussion published in July 2003. First drafts were reviewed by Stephen Newman, Daniel Gaughan, Gary Jackson, Micheal Mackie, Brett Maloney, and Jill St John from Department of Fisheries WA, final editing by Patricia Kailola, and print set up by Sandy Clarke.
Aquaculture-Community Futures: North West Tasmania
Studies of the growth and mortality of school prawns
Dynamic modelling of socio-economic benefits of resource allocation between commercial and recreational use
Modelling Western Australian fisheries with techniques of time series analysis: examining data from a different perspective
1. Responsible management of fisheries requires an assessment of the
success of the management plan in achieving its objectives, together with
an assessment of the state of the fish stock and likely consequences of the
current and alternative management strategies. In many cases, the
management plan is intended to maintain the status quo. Trends in time
series of data, or values that fall outside the range of predicted outcomes,
may indicate that the status quo is not being maintained, or that significant
change has occurred within the system. Cost effective methods are
required to provide rapid feedback to fisheries managers that a major
perturbation has occurred, or that the system is changing, in order that
appropriate management action may be implemented.
2. Need to produce low-cost effective models for stock assessment and catch
prediction of Western Australian fisheries, especially those low-value
fisheries (eg., some finfish fisheries). With few biological assumptions and
simple mathematical forms, time series modeling may significantly reduce
modeling costs including research costs and computing costs. Time series
approaches may also significantly reduce model uncertainty, and therefore
may provide more reliable prediction results.
3. Need to reduce the risk of model failure through inadequate assumptions
regarding biological processes. Models currently used by Fisheries WA
involve often untenable biological assumptions, with the result that
predictions are conditional on the accuracy of the assumptions.
To reduce the risk of model failure through inadequate assumptions, it is
highly desirable to supplement the current models by applying techniques
such as time series methods that make few assumptions regarding the
biological processes and to compare predictions from the two modeling
approaches.
4. Need to incorporate economic data within the models. Little economic
modeling of Western Australian fisheries has been undertaken; and the changing relationships between supply and market demand (especially for the western rock lobster fishery) require study. As an extension of the VOM (Value Optimisation Model for western rock lobster) project (FRDC 97/104), the economic data collected in the earlier project require analysis to determine how these might best be incorporated into the existing models. This research project will address this need by using multivariate time series techniques to identify the relationships among the historical economic data, catch-effort data, exchange rate data, and other related data.
Given the above, time series modeling is seen as a highly valuable and strategic element of the research programme for Western Australian fisheries; the benefits of this project could be transferred Australia-wide to fisheries researchers allowing improved management advice.
Final report
The management of fisheries in Western Australia requires an understanding of the status of the fisheries stocks. For many species, the only available data are catch, effort and CPUE history. For these and other fisheries, time series methods may improve the stock assessment methods. Biological information is expensive to collect, and much of the information required for stock assessment methods such as age-structured models is simply unavailable, especially for low value fisheries. Time series analysis or control charting methods comprise a select few statistical techniques available for the purpose of stock assessment in these cases. Prediction may be improved using time series methods on catch and effort data with or without external data such as biological or environmental variables. Even when biological parameters can be estimated for a given model, time series methods may be superior as prediction tools.
The aim of this research was to apply time series methods on the western rock lobster fishery, several commercial finfish fisheries and the major tiger and king prawn fisheries, and determine how useful these techniques are for fisheries assessment and management.
Socio-ecological assessment of the ecosystems, industries and communities of Spencer Gulf
This project is a case study that addresses science needs identified in the National Marine Science Plan 2015, relating to:
i) systematic collection of environmental, social and economic baseline data;
ii) establishing a monitoring program to support effective management and conservation;
iii) incorporating social, economic and cultural data into marine assessments.
This socio-ecological assessment of Spencer Gulf is needed to evaluate and support future management of the gulfs ecosystems, industries and communities.
It will: i) improve current understanding of the web of interactions that drive patterns and trends in the Gulfs key ecological, economic and social feature and ii) help ensure that ecological, economic and social benefits from future use of the Gulf’s assets are balanced and maximised.
This assessment of Spencer Gulf is needed to build on progress towards 1) ecosystem-based management of the fishing and aquaculture sectors achieved through previous FRDC projects (see references in Goyder application attached) and 2) ecosystem-based management of the gulfs ecosystems, industries and communities (especially stakeholder engagement) achieved as part of the $2.5M industry-funded SGEDI.
Funding provided by FRDC and the Goyder Institute for Water Research are needed to ensure that momentum towards ecosystem-based management achieved through SGEDI previous projects is maintained during a period where the availability of additional industry funds is limited.