Keith Sainsbury

Ecosystem-Based Fishery Management

Ecosystem-based fishery management (EBFM) is a new direction for fishery management, essentially reversing the order of management priorities so that management starts with the ecosystem rather than a target species. EBFM aims to sustain healthy marine ecosystems and the fisheries they support. Pikitch et al . describe the potential benefits of implementation of EBFM that, in their view, far outweigh the difficulties of making the transition from a management system based on maximizing individual species.

Incorporating ecosystem objectives into management of sustainable marine fisheries, including 'best practice' reference points and use of marine protected areas.

The broadening of fisheries management to include ecosystem-related objectives raises a potentially confusing range of possible issues for consideration in management decisions, in reporting, and in assessing management performance. However, there are methods available and approaches to addressing the issues that are practical, accessible to stakeholder participation, and scientifically assessable. Three broad and interrelated elements are described that allow ecosystem objectives to be practically and operationally incorporated into marine fisheries management systems. Reporting and assessment of the whole management system against sustainability objectives. Three major points are developed and emphasized: (i) Indicators and reference points – and consequently performance measures – must explicitly relate to the high-level objectives of management. (ii) The structure and focus of reports on sustainability must be transparently derived from the high-level objectives. A methodology for this is described that can be used in meetings with stakeholders to elucidate the issues, indicators and reference points, management response and the justification for decisions. It can include risk-based methods to help identify the relative importance of different issues. (iii) Performance assessment must be of the management system as a whole, rather than solely on the merits of particular parts in isolation. An established methodology (Management Strategy Evaluation) is described that can be used to quantitatively test the likely performance of different management strategies in achieving ecosystem objectives. A management strategy in this context is a combination of monitoring, use of the monitoring data for assessment against reference points, identification of appropriate management measures, and implementation of these measures. This methodology can be used to test any aspect of the strategy in the “common currency” of the management objectives, and to identify the circumstances in which particular strategies are likely to perform well or fail. It has already been used in fisheries in relation to target species, important by-catch species, predator-prey dependencies, and sea-bed habitats. Keith SAINSBURY Ussif Rashid SUMALIA Keith.Sainsbury@marine.csiro.au R.Sumaila@fisheries.ubc.ca 2 Incorporating ecosystem objectives into management of sustainable marine fisheries K. Sainsbury and U.R. Sumalia Indicators, reference points and performance measures for fisheries ecosystem objectives. There are many options available and some recent summaries are identified. A set of targetand limit-reference points for fisheries ecosystem objectives are provided. These are based broadly on experience to date, and could be practically implemented in the short term. It is not claimed that these reference points are necessary or adequate to achieve sustainability for fisheries and marine ecosystems. Rather, they represent a practical and emerging “best practice” means of operationally accommodating ecosystem-related objectives in fisheries management. Use of marine protected areas to achieve ecosystem objectives in fisheries management Fisheries have long used some forms of spatial management, such as closure of nursery areas to protect juvenile fish, but more recently there has been a focus on use of marine protected areas (MPAs) to achieve fishery objectives for the target species and for the ecosystem more generally. MPAs hold promise as a rational and practical way of managing ocean resources to achieve fishery ecosystem objectives, although this promise should not be overstated. MPAs are best seen as part of a collection of management tools and measures, with a combination of on-reserve and off-reserve measures being used together to achieve sustainable fisheries and marine ecosystems. Several new technological developments are making their design and management more practical. These recent developments are reviewed.

Eco-Label Conveys Reliable Information on Fish Stock Health to Seafood Consumers

Concerns over fishing impacts on marine populations and ecosystems have intensified the need to improve ocean management. One increasingly popular market-based instrument for ecological stewardship is the use of certification and eco-labeling programs to highlight sustainable fisheries with low environmental impacts. The Marine Stewardship Council (MSC) is the most prominent of these programs. Despite widespread discussions about the rigor of the MSC standards, no comprehensive analysis of the performance of MSC-certified fish stocks has yet been conducted. We compared status and abundance trends of 45 certified stocks with those of 179 uncertified stocks, finding that 74% of certified fisheries were above biomass levels that would produce maximum sustainable yield, compared with only 44% of uncertified fisheries. On average, the biomass of certified stocks increased by 46% over the past 10 years, whereas uncertified fisheries increased by just 9%. As part of the MSC process, fisheries initially go through a confidential pre-assessment process. When certified fisheries are compared with those that decline to pursue full certification after pre-assessment, certified stocks had much lower mean exploitation rates (67% of the rate producing maximum sustainable yield vs. 92% for those declining to pursue certification), allowing for more sustainable harvesting and in many cases biomass rebuilding. From a consumer’s point of view this means that MSC-certified seafood is 3–5 times less likely to be subject to harmful fishing than uncertified seafood. Thus, MSC-certification accurately identifies healthy fish stocks and conveys reliable information on stock status to seafood consumers.

An agent-based modelling approach to evaluation of multiple-use management strategies for coastal marine ecosystems

The general objective of the multiple-use management strategy evaluation (MSE) framework is to develop and demonstrate practical science-based methods that support, under existing statutory arrangements, integrated regional planning and management of coastal and marine ecosystems. In the present paper multiple-use MSE is focused on four sectors: oil and gas, conservation, fisheries, and urban and industrial development. A selection of cross-sectoral development scenarios, management strategies and computer representations, provided by the relevant interest groups, is represented. These include prospective future sectoral activities and their impacts, and the sectoral response to alternative management policies and strategies. The agent-based modelling software InVitro is well placed for analysing prospective social and ecological impacts of multiple-use management strategies in a risk-assessment framework such as MSE. An illustrative example is provided to demonstrate the tradeoffs that can be recognised and quantified using the MSE framework. The example explores the implications of a change in management strategy that not only has a direct impact on the targeted sectors, but also indirect impacts, not all of which are to be expected.

Use of fishery-dependent data for the evaluation of depensation: case study involving the predation of rock lobster ( Jasus edwardsii ) by octopus ( Octopus maorum )

Abstract The relationship between the level of octopus (Octopus maorum) predation and the daily‐average number of lobsters (Jasus edwardsii) per pot was investigated using commercial catch statistics. Octopus predation was found to be inversely correlated with lobster catches, such that, lobsters experienced reduced survival when their daily‐average density in a pot was lower. The reduction in survival at lower densities provides evidence for a depen‐satory mechanism underlying the predator‐prey interaction between pot‐caught octopus and lobster. The effect of lobster density on the feeding response of octopus is unknown so this study could not determine whether depensation was brought about by either predator saturation or predator avoidance tactics used by lobsters. The use of commercial catch statistics to investigate this depensatory effect has disadvantages because the lobster mortality estimates can be biased by the non‐reporting of undersized lobsters caught inside pots, under‐reporting of lobsters killed by octopus, the inability to identify unsuccessful predation attempts made by octopus, and the ability of some lobsters to escape from pots. All the sources of bias would tend to make it difficult to conclusively determine both the absolute proportion of lobsters killed by octopus and the true scale of the depensatory mortality, as the scale of the mortality may be greater than the commercial data suggest. However, the bias will not necessarily reduce our ability to detect the depensatory effect if, as seems likely, the sources of bias are relatively constant across the range of daily‐average catches. Depensation in crustacean stocks affected by pot‐related octopus predation has been rarely studied, and, because depleted stocks lead to fewer lobsters being caught per pot, such depensatory mortality has implications for the population dynamics and management of crustacean stocks.

Linking ocean models to coastal management on Australia's north west shelf

The need for integrated environmental studies to support the management of marine systems is now widely accepted. A significant number of such studies have been undertaken in the past two decades, particularly in coastal bays and estuaries; see, for example, Harris and Crossland [1999]. These studies have generally led to improved scientific understanding of various components of the natural ecosystem and direct impacts of human activities. However, the integration of this information into a single coherent framework has usually only been attempted in the final stages of a project or not at all [Knuttle, 2000]. Managers are then left with the daunting task of interpreting a disparate set of scientific results and incorporating them into a decision-making process.

CCAMLR’s precautionary approach to management focusing on Ross Sea toothfish fishery

Abstract Several recent papers have criticized the scientific robustness of the fisheries management system used by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), including that for Ross Sea toothfish. Here we present a response from the wider CCAMLR community to address concerns and to correct some apparent misconceptions about how CCAMLR acts to promote conservation whilst allowing safe exploitation in all of its fisheries. A key aspect of CCAMLR’s approach is its adaptive feedback nature; regular monitoring and analysis allows for adjustments to be made, as necessary, to provide a robust management system despite the statistical uncertainties inherent in any single assessment. Within the Ross Sea, application of CCAMLR’s precautionary approach has allowed the toothfish fishery to develop in a steady fashion with an associated accumulation of data and greater scientific understanding. Regular stock assessments of the fishery have been carried out since 2005, and the 2013 stock assessment estimated current spawning stock biomass to be at 75% of the pre-exploitation level. There will always be additional uncertainties which need to be addressed, but where information is lacking the CCAMLR approach to management ensures exploitation rates are at a level commensurate with a precautionary approach.

Trawl cod-end mesh selectivity for some fishes of North-Western Australia

Abstract A cod-end mesh selectivity experiment was conducted using the covered cod-end technique on the continental shelf of northern Australia. Cod-end (stretched) mesh sizes of 40, 51, 55, 70 and 100 mm were tested with a 30-mm-mesh cover bag. Mesh selection parameters were estimated for 28 species by fitting a logistic curve to the size-specific escapement data, and a gross selection rate was calculated for an additional 27 species. Some species (notably Lutjanus spp., Pristipomoides spp. and Plectorhynchus pictus ) were largely retained by all cod-end mesh sizes tested, while others (notably Loligo spp.) largely escaped all the cod-ends tested. The common assumption that the selection factor does not alter with mesh size was accepted for Nemipterus nematopus, Parupeneus pleurospilus and Lutjanus vittus , but rejected for Saurida undosquamis . Dependence of the selection factor upon mesh size for S. undosquamis was due to a non-zero intercept in the relationship between fish size at 50% escapement and mesh size. The general implications of dependence of selection factor on mesh size are discussed.