Managing global shark fisheries: suggestions for prioritizing management strategies

• 1. Over the past two decades the number of fisheries targeting shark resources has increased dramatically. A combination of factors, including relatively slow growth rate, low fecundity and late age of maturity, result in low recovery rates from exploitation for most shark species. This, in turn, is reflected in the poor record of sustainability of shark fisheries.
• 2. One of the greatest challenges is to find a way to deal with the substantial levels of shark bycatch taken in many non‐target fisheries. Poor general recording of shark landings and paucity of shark landing data at the species level also undermine the development of effective shark management strategies. 3. This paper reviews the problems that must be faced worldwide if shark resources are to be managed sustainably and lays out a comprehensive set of prioritized management strategies to facilitate the sustainable management of global shark fisheries. It is acknowledged that the majority of sharks are harvested in developing countries and that the management of shark resources in developing and developed countries will need to incorporate different management strategies relevant to local socio‐economic agendas. The management recommendations deal with methods to improve the global regulation of fisheries, ways to improve global conservation ethics and encourage active participation in management, as well as means by which specific management strategies may be implemented.

Copyright © 2004 John Wiley & Sons, Ltd.     

Checking the pulse of the major commercial fisheries of lake Victoria Kenya,for sustainable management

The present study demonstrates the declining state of the major commercial fisheries of Lake Victoria, Kenya, a situation threatening sustainability of the lake's fishery. Data in the present study were derived from resource monitoring programmes that included hydro‐acoustics (2009–2018), trawl net fishing (2011–2018), frame surveys (2000–2016) and catch assessment surveys (2000–2015). The activities provided information on fish stocks and supported advice for fisheries management. The average fish stock densities for Tanzania, Uganda and Kenya of 8.92, 8.25 and 8.19 t/km², respectively, were relatively similar. Diplomatic and sustainable efforts for harmony in fish harvesting among the fishers of the riparian countries are encouraged given the interdependence of the lake. The Kenyan and River Kagera regions had a higher proportion (≈ 4% each) of big‐sized Nile perch (≥50 cm total length) in 2018, signifying the critical breeding areas for Nile perch. To sustain the fishery, there is need to enforce a 36%–44% effort reduction for all the major fisheries, and enforcement of gear limits to avoid harvesting of immature fish and destruction of the lake ecosystem.     

Inland commercial fisheries management in France

The French fisheries management regime is based on public and private ownership of fishing waters associated with a complex multilevel management system. A total of 730 operational commercial inland fisheries were examined by analysis of thematic interviews and questionnaires. Commercial fishermen are beginning to understand the nature of their own activity and its relationship to the concept of sustainable management. Nevertheless, fishermen have to face two major problems: first, they are poorly represented on decision making bodies where anglers are dominant, and secondly their activities are governed by two separate ministries. Opportunities for future development may lie in decision making at the catchment level.     

Gear restrictions create conservation and fisheries trade-offs for management

Gear-based management for coral reef fisheries is often overlooked in the scientific literature. Empirical studies have demonstrated the conservation benefits of gear-restricted areas (i.e. prohibiting fishing gears), which can support greater biomass than unrestricted areas and protect species that play key functional roles. However, population dynamics of functional feeding groups of reef fishes under specific gear-restriction regimes remains uncertain. Here, we constructed a multi-species, length-based fisheries model to observe relative biomass and catch of reef fishes under various gear-restriction management scenarios. We used fishery-dependent and fishery-independent data to determine the catchability of functional groups and selectivity of size classes for hook-and-line, net and spear fishing, which are widely used gear types on coral reefs globally. Our model revealed trade-offs involved with gear-restriction management such that no single management strategy was able to maximize biomass or catch of all functional groups simultaneously. Also, we found that spear fishing (i.e. prohibiting hook-and-line and net fishing) maintained the highest total biomass summed across functional groups, whilst hook-and-line fishing (i.e. prohibiting net and spear fishing) and a ban on spears maintained the lowest biomass. However, hook-and-line fishing generated the highest catch-per-unit-effort. Our model results were primarily driven by differential growth rates, maximum per capita production of recruits, and catchability of functional groups targeted by each fishing gear. We demonstrate that gear restrictions can be a critical management tool for maintaining biomass and catch of certain functional groups but will likely require additional management to protect all key functional feeding groups of coral reef fishes.     

Towards sustainable fisheries and aquaculture management in the African Great Lakes

Inland fisheries play important roles in food and economic security in the riparian countries surrounding the Great Lakes of Africa. However, the lakes are being systematically degraded by anthropogenic pressures, in combination with the huge population growth prevalent in the region. This paper summarises the outcomes of an international conference to develop a ‘Strategy for Conservation and Sustainable Development of the African Great Lakes Region in a Changing Climate’, held in Uganda in 2017, with particular attention on the potential for fisheries and aquaculture. The paper highlights options for addressing the problems facing the aquatic resources and specifically the importance of effective management of the fisheries and ecosystems of the Great Lakes to achieving the UN Sustainable Development Goals to ensure food and nutritional security and sustainable livelihoods. There is need to improve fisheries assessment and determine the value of the fisheries (and aquaculture). Fisheries legislation, regulation and enforcement need revision and co‐management mechanisms require rethinking. There is considerable potential for aquaculture, and especially cage culture, to increase fish production, but there is an urgent need to address technical, social, environmental and input requirements. It is also imperative that best practices guidelines are developed that will support cage culture production practices.     

Elasmobranch fisheries in the Arabian Seas Region: Characteristics,trade and management

The Arabian Seas Region plays an important role in the global landings and trade of sharks and rays. The United Arab Emirates (UAE) and Yemen, two countries with stark socio‐economic differences, serve as major regional trade hubs for shark and ray products and four countries (Oman, Pakistan, UAE and Yemen) supply nearly 11% of dried fin exports to Hong Kong. Yet, little information is available on the characteristics of this trade and the fisheries contributing to it. Here, we review the fisheries characteristics, trade, utilization and distribution chain of sharks and rays in 15 countries of the Arabian Seas Region based on published and grey literature, landing surveys, field observations and interviews with fishermen and traders. Although regional shark fisheries remain mostly artisanal, reported shark and ray landings represent 28% of the regional total fish production, reaching 56,074 mt in 2012 (7.3% of total world catches), with Iran, Oman, Pakistan and Yemen ranking as the primary catchers. Utilization and distribution patterns are complex, vary between landing sites and countries, and remain unmonitored. Based on widespread over‐exploitation of most teleost fisheries, current exploitation levels for most sharks and rays are potentially unsustainable. The situation is exacerbated by limited research and political will to support policy development, the incomplete nature of fisheries data, as well as insufficient regulations and enforcement. A better understanding of shark and ray fisheries will be key for regulating trade, promoting conservation and developing management initiatives to secure food security, livelihoods and biodiversity conservation in the region.     

Community-based management of subsistence fisheries in Samoa

Much subsistence fishing in tropical regions is based in discrete communities which have a high level of marine awareness and some degree of control of adjacent waters. These factors provide an ideal basis on which to motivate communities to manage their own marine resources. A fisheries extension programme in Samoa encouraged each village community to define its key problems, discuss causes, propose solutions and take appropriate actions. Various village groups, including women's and untitled men's groups, provided information which was recorded (as problem/solution trees) on portable white-boards. The extension process culminated in a community-owned Fisheries Management Plan which listed the resource management and conservation undertakings of the community. Undertakings ranged from enforcing laws banning destructive fishing methods to protecting critical marine habitats. Within the first 2 years, the extension process commenced in 65 villages, of which 44 have produced Village Fisheries Management Plans to date. A large number (38) of these villages chose to establish community-owned Marine Protected Areas.     

Risk management for fisheries

Risk management methods provide means to address increasing complexity for successful fisheries management by systematically identifying and coping with risk. The objective of this study is to summarize risk management practices in use in fisheries and to present strategies that are not currently used but may be applicable. Available tools originate from a variety of disciplines and are as diverse as the risks they address, including algorithms to aid in making decisions with multiple stakeholders, reserves to buffer against economic or biological surprises, and insurance instruments to help fishermen cope with economic variability. Techniques are organized in a two‐stage framework. In the first stage, risks are identified and analysed. Strategies presented in this category focus on decision analysis, including multicriteria decision‐making tools, and the related concept of risk assessment. Then in the treatment stage, identified risks can be transferred, avoided, or retained using tools such as the Precautionary Approach, portfolio management, financial contracts to manage price risk and horizontal integration. Published fishery applications are reviewed, and some empirical examples of risks and risk management using US fisheries data are presented.     

渔业生态系统方法简述

考虑到生态系统状态对渔业的重要影响,渔业生态系统方法(Ecosystem Approach to Fisheries,EAF)把对生态的关注加入渔业管理框架中,并以生态系统管理和渔业管理2个理论为基础,扩展了传统渔业管理的框架:以生态系统健康与人类福利的依存关系为基础,关注多物种管理,均衡生态、人文和制度3个维度的目标,实现渔业的可持续发展。本研究介绍了EAF的由来、定义、基本原则以及功能要素,概述了EAF的实践基础和模型构建的技术路径,对比了EAF与EBFM的异同。虽然EAF的理论和实践仍处于完善和发展阶段,但确为渔业管理的发展方向,介绍EAF对促进我国渔业可持续发展具有重要意义。     

Re-imagining the precautionary approach to make collaborative fisheries management inclusive of Indigenous Knowledge Systems

Fisheries science uses quantitative methods to inform management decisions that reflect cultural preferences which, in turn, indirectly influence the states of ecosystems. To date, it has largely supported Eurocentric preferences for the commodification of marine organisms under the tenets of maximum sustainable yield, whereby abundances are intentionally maintained far below their historical baselines despite broader socio-ecological trade-offs. In contrast, Indigenous Knowledge Systems (IKS) adhere to the principle of “take only what you need and leave lots for the ecosystem,” implementing lower fishery removals to support socio-ecological resilience. Despite the power imbalance favouring Eurocentric preferences in decision-making, fisheries scientists increasingly recognize that the pairing of IKS and Western science, or Two-Eyed Seeing, would lead to more holistic management goals. For recognition to transcend tokenism, meaningful collaborations and co-governance structures underlying knowledge co-production must carry through to legislated policy changes. Using recent co-governance developments for fisheries management and spatial protections involving federal, provincial and Indigenous governments in Pacific Canada, we illustrate how the precautionary approach, including reference points and harvest control rules broadly applied in international fisheries, could be revised to make collaborative fisheries management compatible with IKS and improve biodiversity and fisheries protections. Our recommendations may create socio-economic trade-offs at different timescales for commercial fishers. Pre-empting that challenge, we discuss IKS-compatible economic approaches for addressing shorter term costs arising from reduced exploitation rates. Although our case study derives from Pacific Canada, the insights provided here are broadly applicable elsewhere in the world.     

Considering recreational catch and harvest in fisheries management at the bio‐regional scale

Abstract The Gulf of Carpentaria in northern Australia supports several commercial fisheries and a largely tourist‐based recreational fishery. The results of a survey of 427 recreational fishing parties visiting the main town, Karumba, between March and September 2006 were examined using the bootstrap method to estimate confidence intervals for mean tourist catch and harvest of grunter, Pomadasys kaakan (Cuvier), and other recreational target species. Tourist anglers harvested between 99.8 and 117 t of P. kaakan and 32.6–38.2 t of blue salmon, Eleutheronema tetradactylum (Shaw), during the survey period. Resident recreational anglers harvested an additional 15–35 t of P. kaakan, but very little E. tetradactylum. In comparison, commercial harvest was 19 t of P. kaakan and 64 t of E. tetradactylum in the whole of the Queensland section of the Gulf of Carpentaria. The results underscore the need for appropriately collected recreational fishing data to support integrated fisheries management at the bioregional scale, and in the case of angling‐based tourist destinations, underpin a diversification of the tourist product.     

BMEY as a fisheries management target

This paper evaluates the implications of managing fisheries to achieve a B_MEY target, or a biomass level that maximizes net economic returns in the fishery, and discusses the role of private ownership and the trade‐offs between economic and conservation benefits in this setting. The paper shows how a B_MEY target can be used to: (i) determine relative employment and profitability measures; (ii) account for both the harvesting and processing sectors; and (iii) incorporate the interests of consumers and producers of fish. The profits–employment trade‐off of adopting a B_MEY target vs. a traditional B_MSY target is calculated using a model and data from the Western and Central Pacific tuna fisheries (WCPTF), while a generic bioeconomic model is constructed to show numerical values of B_MEY from including processing and/or retail sectors and the consumer benefits of harvesting fish. For the WCPTF, results show that the long‐term gains per job lost from pursuing a B_MEY target are worth several times the value of the average GDP per capita of Pacific Island Countries. The generic bioeconomic model shows that including a processing and/or retail sector, as well as measures of consumer benefit, lowers the B_MEY target. However, there remains a broad range of parameter values for which B_MEY is still greater than biomass at maximum sustainable yield, or B_MSY. The paper also illustrates cases where B_MEY > B_MSY at different values of the price elasticity of demand, margins for processing and/or retail sectors and values of the discount rate.     

Changing how we approach fisheries: A first attempt at an operational framework for ecosystem approaches to fisheries management

The increasing need to account for the many factors that influence fish population dynamics, particularly those external to the population, has led to repeated calls for an ecosystem approach to fisheries management (EAFM). Yet systematically and clearly addressing these factors, and hence implementing EAFM, has suffered from a lack of clear operational guidance. Here, we propose 13 main factors (shift in location, migration route or timing, overfishing (three types), decrease in physiology, increase in predation, increase in competition, decrease in prey availability, increase in disease or parasites and a decline in habitat quality or habitat quantity) that can negatively influence fish populations via mechanisms readily observable in ~20 population features. Using these features as part of a diagnostic framework, we develop flow charts that link probable mechanism(s) underlying population change to the most judicious management actions. We then apply the framework for example case studies that have well‐known and documented population dynamics. To our knowledge, this is the first attempt to provide a clearly defined matrix of all the probable responses to the most common factors influencing fish populations, and to examine possible diagnostics simultaneously, comparatively and relatively in an attempt to elucidate the most probable mechanisms responsible. The framework we propose aims to operationalize EAFM, thereby not only better diagnosing factors influencing fish populations, but also suggesting the most appropriate management interventions, and ultimately leading to improved fisheries. We assert the framework proposed should result in both better use of limited analytical and observational resources and more tailored and effective management actions.     

Forage fish fisheries management requires a tailored approach to balance trade‐offs

Ecosystem‐based fishery management requires considering the effects of actions on social, natural and economic systems. These considerations are important for forage fish fisheries, because these species provide ecosystem services as a key prey in food webs and support valuable commercial fisheries. Forage fish stocks fluctuate naturally, and fishing may make these fluctuations more pronounced, yet harvest strategies intended to ameliorate these effects might adversely affect fisheries and communities. Here, we evaluate trade‐offs among a diverse suite of management objectives by simulating outcomes from several harvest strategies on forage fish species. We demonstrate that some trade‐offs (like those between catches and minimizing collapse length) were universal among forage species and could not be eliminated by the use of different control rules. We also demonstrate that trade‐offs vary among forage fish species, with strong trade‐offs between stable, high catches and high‐biomass periods (“bonanzas”) for menhaden‐ and anchovy‐like fish, and counterintuitive trade‐offs for sardine‐like fish between shorter collapses and longer bonanzas. We find that harvest strategies designed to maintain stability in catches will result in more severe collapses. Finally, we show that the ability of assessments to detect rapid changes in population status greatly affects control rule performance and the degree and type of trade‐offs, increasing the risk and severity of collapses and reducing catches. Together, these results demonstrate that while default harvest strategies are useful in data‐poor situations, management strategy evaluations that are tailored to specific forage fish may better balance trade‐offs.     

Toward sustainable harvest strategies for marine fisheries that include recreational fishing

Recreational fishing (RF) is a large yet undervalued component of fisheries globally. While progress has been made in monitoring, assessing, and managing the sector in isolation, integration of RF into the management of multi-sector fisheries has been limited, particularly relative to the commercial sector. This marginalises recreational fishers and reduces the likelihood of achieving the sector's objectives and, more broadly, achieving fisheries sustainability. We examined the nature and extent of RF inclusion in harvest strategies (HSs) for marine fisheries across 15 regions in 11 nations to define the gap in inclusion that has developed between sectors. We focused on high-income nations with a high level of RF governance and used a questionnaire to elicit expert knowledge on HSs due to the paucity of published documents. In total, 339 HSs were considered. We found that RF inclusion in HSs was more similar to the small-scale sector (i.e., artisanal, cultural, or subsistence) than the commercial sector, with explicit operational objectives, data collection, performance indicators, reference points, and management controls lacking in many regions. Where specified, RF objectives focused on sustainability, economic value and catch allocation rather than directly relating to the recreational fishing experience. Conflicts with other sectors included competition with the commercial sector for limited resources, highlighting the importance of equitable resource allocation policies alongside HSs. We propose that RF be explicitly incorporated into HSs to ensure fisheries are ecologically, economically, and socially sustainable, and we recommend that fisheries organisations urgently review HSs for marine fisheries with a recreational component to close the harvest strategy gap among sectors.     

Assessing a social norms approach for improving recreational fisheries compliance

This study aimed to assess the suitability of the Berkowitz' ( 2005 ) social norms approach (SNA) for improving compliance behaviour amongst recreational fishers. A total of 138 recreational shore anglers were interviewed in Eastern Cape, South Africa and asked about their compliance, attitudes towards compliance, perceptions of compliance and the attitudes of other anglers. Results indicate that angler compliance for individual regulations was relatively high (75%–90%). Attitudes of anglers towards compliance was positive, with >80% feeling that “breaking any regulation is wrong.” Yet, as predicted by the SNA, interviewees often overestimated the non‐compliance and negative attitudes of other anglers, particularly as their social proximity decreased. Interviewees with the greatest misperceptions were also less compliant. The social norms present in the Eastern Cape rock and surf fishery fulfil the criteria required for the application of the SNA, suggesting that this approach may provide a suitable normative intervention for improving compliance to be used in conjunction with instrumental approaches in recreational fisheries.     

Ecosystems say good management pays off

Understanding the strengths and weaknesses of alternative assessment methods, harvest strategies and management approaches are an important part of operationalizing single‐species and ecosystem‐based fisheries management. Simulations run using two variants of a whole‐of‐ecosystem model for the Southern and Eastern Scalefish and Shark Fishery (SESSF) area shows that (a) data‐rich assessments outperform data‐poor assessments for target species and that this performance is reflected in the values of many system‐level ecosystem indicators; (b) ecosystem and multispecies management outperforms single‐species management applied over the same domain; (c) investment in robust science‐based fisheries management pays dividends even when there are multiple jurisdictions, some of which are not implementing effective management; and (d) that multispecies yield‐oriented strategies can deliver higher total catches without a notable decline in overall system performance, although the resulting system structure is different to that obtained with other forms of ecosystem‐based management.