Natalie Dowling

Reconciling Approaches to the Assessment and Management of Data-Poor Species and Fisheries with Australia's Harvest Strategy Policy

Abstract There is an increasing expectation for decision makers to use robust scientific advice on the status of exploited fish stocks. For example, Australia has recently implemented a harvest strategy policy for federally managed fisheries based on limit and target biomass reference points. In common with most fisheries jurisdictions, however, Australia has many data-poor species and fisheries for which biomass estimates are unavailable. Consequently, the challenge for those tasked with providing management advice for Australian fisheries has been reconciling the need to achieve specific risk-related sustainability objectives with the reality of the available data and assessments for data-poor species and fisheries. Some general recommendations regarding how to achieve this balance are drawn using case studies from two multispecies trawl fisheries. The lack of data on which to base quantitative stock assessments using population dynamics models does not preclude the development of objective harvest control rules. Evaluation of harvest control rules using technical procedures (e.g., the management strategy evaluation approach) is ideal, but implementation before rigorous testing is sometimes a necessary reality. Information from data-rich species and fisheries can be used to inform “assessments” for data-poor species and thereby develop appropriate control rules. This can be done through formal methods, such as the “Robin Hood” approach (in which assessments from data-rich species are used to inform assessments of data-poor species), or less formally by grouping species into “baskets” and basing management decisions on one appropriate member of the group. Stakeholder knowledge and buy-in to the process of developing appropriate harvest strategies are essential when species or fisheries are data poor. Use of this information, however, needs to be constrained by policy decisions, such as prespecified performance standards. There will always be a trade-off between the cost of data collection and the value of a fishery; in this article, we highlight that this trade-off does not have to be a major impediment to the development of realistic and sufficiently precautionary control rules for the management of data-poor species and fisheries.

Economic and conservation implications of a variable effort penalty system in effort-controlled fisheries

Bycatch of threatened, endangered or protected species by commercial fishers is a universal problem. Technical solutions are often applied that may impose inefficiencies across the fleet, even in periods or areas when the risk of bycatch is low. These may include gear specifically designed to avoid the bycatch which may also reduce the targeted catch, or designation of marine protected areas that exclude fishing from whole areas. In this article, we examine the effectiveness of a variable penalty system that can provide incentives for fishers to redirect their effort away from problem areas. The system is examined using a case study of fishery, which is currently subjected to gear and closure controls to limit bycatch of turtles and seabirds. An alternative incentive-based management policy using a series of differential hook penalties has been proposed as a flexible tool to discourage vessels operating in certain areas. The effects of various hook penalties and closures in key areas on fishing effort in those areas and elsewhere as well as vessel economic performance are assessed using a location choice model. The results suggest that incentive-based approaches may result in lower costs to industry than closures provided some level of residual bycatch is acceptable.

From data rich to data-limited harvest strategies—does more data mean better management?

From data rich to data-limited harvest strategies—does more data mean better management? Catherine M. Dichmont*, Elizabeth A. Fulton, Rebecca Gorton, Miriana Sporcic, L. Richard Little, André E. Punt, Natalie Dowling, Malcolm Haddon, Neil Klaer, and David C. Smith CSIRO Oceans and Atmosphere, Ecosciences Precinct, Dutton Park, QLD 4750, Australia Cathy Dichmont Consulting, 47 Pioneer Road, Redlands, QLD 4157, Australia Sheldon CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, TAS 7001, Australia School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195, USA *Corresponding author: tel: þ61 7 3206 056; e-mail: cathydichmont@gmail.com

Reference Points for Optimal Yield: A Framework for Assessing Economic, Conservation, and Sociocultural Tradeoffs in Ecosystem-Based Fishery Management

ABSTRACT We propose a conceptual framework for evaluating fishery management performance using conservation, economic, and sociocultural metrics. We develop a value function that weights outcomes for each measure based on their relative importance to decision makers and show how it can be derived from fundamental economic principles (the latter initially in collaboration with Mark Plummer). This approach allows one to explore how Optimal Yield, as mandated by the Magnuson-Stevens Act, varies with biological, economic, and sociocultural weightings.