Approaches to fully documented fisheries: practical issues and stakeholder perceptions

The Common Fisheries Policy (CFP) reform sets out a move to a land‐all catch policy in European Union waters with a requirement for full reporting of fishing and on‐board processing activity. We explore the merits, stakeholder perceptions and applicability of different technology and approaches to the full documentation of fisheries that might be considered in the context of implementing the CFP reform. While recent efforts have focused on demonstrating how remote electronic monitoring (REM) systems can be utilized in fully documented fisheries (FDF), other technologies and approaches such as reference fleet and self‐sampling exist that could contribute to delivering FDF. Perceptions of fishers show that they would prefer using a reference fleet or self‐sampling to REM systems as a future method of implementing FDF. In general, there is support from the fishing industry for data collection and enhancement, but there remains some mistrust concerning the use of the data. Findings show that the most appropriate means and methods of FDF will depend on the circumstances and objectives for full documentation whether in enforcing a discard ban, documentation of total catch or data enhancement. We conclude that any technology or approach that will be used to deliver the monitoring requirements for FDF needs to make practical and commercial sense at the fishing vessel level.     

Reforming the European Common Fisheries Policy: a case for capacity and effort controls

I summarize the total allowable catch (TAC) fishery management system, which forms part of the European Common Fisheries Policy (CFP) as complicated, inaccurate and ineffective. Total allowable effort (TAE), i.e. limits on fishing capacity and days‐at‐sea, provides a simpler, readily enforceable control to protect all species affected by a fishery. Fishing capacity of vessels in each region‐gear fleet could be capped through limits on engine power, gear, crew, and fittings, and/or reducing allowances of days‐at‐sea for large, powerful vessels. Two basic, fishery‐dependent indicators are put forward to assess sustainability of a fishery dependably even in the absence of fishery‐independent data. One is socio‐economic, the other is ecological. Fishery working groups within each marine region would recommend a TAE to sustain their fishery while also protecting the most critically affected species or processes. Regional working groups would supervise a consistent approach across the different fisheries in their region. A pan‐European group would set policy, implement external agreements, set rules for trading TAE if necessary and harmonize fishing opportunities across regions. To ease negotiations on TAEs with the fishing industry when an ecosystem needs to recover, I propose compensation payments funded by re‐direction of existing CFP subsidies that promote fishing.     

Real‐time spatial management approaches to reduce bycatch and discards: experiences from Europe and the United States

Spatial management measures are currently being used to manage bycatch and discards, given the spatial heterogeneity of fish distributions. However, permanent fishing closures are often poorly implemented, unresponsive to stock dynamics and do not achieve their management objectives. Recently, real‐time spatial management tools for managing bycatch and discards implemented under either a comanagement or self‐governance approach have been introduced in Europe and the US. Real‐time catch and discard information is shared among fishers to incentivise and encourage vessels to leave areas of high bycatch. Here, the similarities and differences, in governance, implementation and management of ten real‐time spatial management systems from across Europe and the US are reviewed. A framework is developed to characterize the attributes associated with voluntary, private and regulatory real‐time spatial management tools. Challenges and management practices in the different case studies are reviewed providing insights for designing these spatial management tools. The results illustrate that real‐time spatial management approaches can create incentives for fishers to develop, use and share information and technology to avoid undesired catch. Compared with Europe, the US has developed spatial management tools with more truly real‐time mechanisms and with greater involvement of the fishing industry in designing and operating the tools.     

Mitigating unaccounted fishing mortality from gillnets and traps

Gillnets and traps often are considered to have fewer holistic environmental impacts than active fishing gears. However, in addition to the targeted catches, gillnets and traps still cause unwanted mortalities due to (i) discarding, (ii) ghost fishing of derelict gear, (iii) depredation, (iv) escaping or dropping out of gear, (v) habitat damage, and potentially (vi) avoiding gear and predation and (vii) infection of injuries sustained from most of the above. Population‐level concerns associated with such ‘unaccounted fishing mortalities’ from gillnets and traps have been sufficient to warrant numerous attempts at mitigation. In this article, we reviewed relevant research efforts, locating 130 studies in the primary literature that concomitantly quantified mortalities and their resolution through technical modifications, with the division of effort indicating ongoing concerns. Most studies (85) have focused on discard mortality, followed by ghost‐fishing (24), depredation (10) and escape (8) mortalities. The remaining components have been poorly studied (3). All problematic mortality components are affected by key biological (e.g. species), technical (e.g. fishing mechanisms) and/or environmental (e.g. temperature) factors. We propose that these key factors should be considered as part of a strategy to reduce impacts of these gears by first assessing modifications within and then beyond conventional configurations, followed by changes to operational and handling practices. Justification for this three‐tiered approach is based not only on the potential for cumulative reduction benefits, but also on the likely ease of adoption, legislation and compliance.     

A synthesis to understand responses to capture stressors among fish discarded from commercial fisheries and options for mitigating their severity

Discarding non‐target fish from commercial fisheries is controversial and has been a persistent concern for fisheries managers globally. Discard management strategies typically begin by understanding mortality rates among discarded fish, a challenging task given the dynamic, highly context‐specific nature of fisheries. An alternative is to develop our knowledge of how stressors operate by first understanding the causes of mortality that drive this context dependence. Particularly relevant to mitigation efforts is an understanding of how fish respond to the physical factors of fishing, such as the gear itself and methods of fishing and handling the gear. We provide a synthesis of how commercial fishing methods may influence discard mortality and outline means by which capture‐induced stress and injury can be mitigated for common commercial gear types, emphasizing method variants or alternatives during capture, handling, and release that could improve survival. This synthesis identifies exhaustion and injury as the most detrimental and ubiquitous stressors experienced by discarded fish, with few options for mitigating their effects. Trawls and hanging net fisheries are identified as the most harmful gears for by‐catch, characterized by high stress regardless of method variants and limited options for mitigation. Irrespective of gear type and type of stressor, minimizing durations of capture and handling and encouragement of good handling behaviour (e.g., during landing and sorting) will reduce the magnitude of stress and injury in fish, and ultimately increase survival.     

Influences of gear type and analytical methodology on fish assemblage characterisations in temperate lakes

A variety of gears and analytical methods can be used to characterise lentic fish assemblages; however, the combined influence of gear type and analysis can affect conclusions about assemblage patterns. Fish assemblages sampled with night electric fishing, gillnets and trapnets from 153 lakes were evaluated using summary indices of species composition, pairwise community similarity comparisons and multivariate ordination. For a given amount of effort, electric fishing had the highest species richness, while gillnets had higher diversity and evenness. Pairwise comparisons between gears revealed that (1) richness was positively correlated among all gears, (2) diversity and evenness were generally not correlated across gears and (3) electric fishing and trapnets captured more similar species than all other pairwise comparisons. Gear‐specific multivariate correlation and ordination revealed that gillnet and electric fishing samples more similarly characterised variation in assemblages among lakes, while trapnets characterised assemblages along different gradients of species composition. These results indicate that either electric fishing or trapnetting can be used when assessing shallow‐water assemblages for diversity or evenness, gillnets and either electric fishing or trapnets should be used for whole‐lake assessments, and either gillnets or electric fishing should be used when evaluating regionwide variation in lake assemblages.     

Response of benthic fauna to experimental bottom fishing: A global meta‐analysis

Bottom‐contact fishing gears are globally the most widespread anthropogenic sources of direct disturbance to the seabed and associated biota. Managing these fishing disturbances requires quantification of gear impacts on biota and the rate of recovery following disturbance. We undertook a systematic review and meta‐analysis of 122 experiments on the effects‐of‐bottom fishing to quantify the removal of benthos in the path of the fishing gear and to estimate rates of recovery following disturbance. A gear pass reduced benthic invertebrate abundance by 26% and species richness by 19%. The effect was strongly gear‐specific, with gears that penetrate deeper into the sediment having a significantly larger impact than those that penetrate less. Sediment composition (% mud and presence of biogenic habitat) and the history of fishing disturbance prior to an experimental fishing event were also important predictors of depletion, with communities in areas that were not previously fished, predominantly muddy or biogenic habitats being more strongly affected by fishing. Sessile and low mobility biota with longer life‐spans such as sponges, soft corals and bivalves took much longer to recover after fishing (>3 year) than mobile biota with shorter life‐spans such as polychaetes and malacostracans (<1 year). This meta‐analysis provides insights into the dynamics of recovery. Our estimates of depletion along with estimates of recovery rates and large‐scale, high‐resolution maps of fishing frequency and habitat will support more rigorous assessment of the environmental impacts of bottom‐contact gears, thus supporting better informed choices in trade‐offs between environmental impacts and fish production.     

Estimating collateral mortality from towed fishing gear

More than 50% of the world's total marine catch (approximately 81 million tonnes) is harvested using towed fishing gears (i.e. Danish seines, dredges and otter and beam trawls). As for all methods, the total fishing mortality of these gears comprises the reported (landed) and unreported catch and other unaccounted, collateral deaths due to (i) avoiding, (ii) escaping, (iii) dropping out of the gear during fishing, (iv) discarding from the vessel, (v) ghost fishing of lost gear, (vi) habitat destruction or subsequent (vii) predation and (viii) infection from any of the above. The inherent poor selectivity of many towed gears, combined with their broad spatial deployment, means that there is considerable potential for cumulative effects of (i)–(viii) listed above on total fishing mortality, and subsequent wide‐scale negative impacts on stocks of important species. In this paper, we develop a strategy for minimizing this unwanted exploitation by reviewing all the primary literature studies that have estimated collateral, unaccounted fishing mortalities and identifying the key causal factors. We located more than 80 relevant published studies (between 1890 and early 2006) that quantified the mortalities of more than 120 species of escaping (26 papers) or discarded (62 papers) bivalves, cephalopods, crustaceans, echinoderms, elasmobranches, reptiles, teleosts and miscellaneous organisms. Seven of these studies also included the estimates of mortalities caused by dropping out of gears, predation and infection [(iii), (vii) and (viii) listed above]. Owing to several key biological (physiology, size and catch volume and composition), environmental (temperature, hypoxia, sea state and availability of light) and technical (gear design, tow duration and speed) factors, catch‐and‐escape or catch‐and‐discarding mechanisms were identified to evoke cumulative negative effects on the health of most organisms. We propose that because the mortalities of discards typically are much greater than escapees, the primary focus of efforts to mitigate unaccounted fishing mortalities should concentrate on the rapid, passive, size and species selection of non‐target organisms from the anterior sections of towed gears during fishing. Once maximum selection has been achieved and demonstrated to cause few mortalities, efforts should be made to modify other operational and/or post‐capture handling procedures that address the key causal factors listed above.     

A framework for adaptive gear and ecosystem‐based management in the artisanal coral reef fishery of Papua New Guinea

• 1. Artisanal fishing on coral reefs in Papua New Guinea is an important livelihood activity that is managed primarily at the level of local communities. Pockets of overexploitation exist and are expected to increase with plans for increased commercialization.
• 2. This paper provides a current assessment of the artisanal multi‐species coral reef fishery by examining selectivity of the dominant gear, namely line fishing, spearguns, and gill nets. Each gear has its own strengths and weaknesses in terms of use and conservation of resources, with no clear problem gear.
• 3. The three gears utilize different resources but there was moderate overlap in the species caught, particularly between gill nets and line fishing and marginally between lines and spearguns. Gill nets have the disadvantage of being destructive to coral and the advantage of catching commercial species. Line fishing catches an intermediate number of species but mostly large‐bodied and predatory species that could potentially reduce predation and the mean trophic level of the fishery. Spearguns catch the highest numbers of species, including many non‐commercial and herbivorous fish and could reduce the diversity of fish and encourage algal growth.
• 4. This information could be used in combination with scientific monitoring and traditional ecological knowledge to develop an adaptive management framework that uses local restrictions on the various gears to restore or balance the fishery and ecosystem. Restrictions could be selectively imposed: on gill nets when coral cover is low, line fishing when large‐bodied predators are depleted, and spearguns when biodiversity is reduced and algal abundance high.

Copyright © 2008 John Wiley & Sons, Ltd.     

The use of spatial management tools in rights‐based groundfish fisheries

The role of spatial management, including marine protected areas, in achieving fisheries outcomes alongside conservation goals is debated. In fisheries that fail to meet fishing mortality targets, closed areas are sometimes implemented to reduce fishing mortality. However, fisheries with stronger management, including rights‐based approaches that can address overcapacity and overfishing problems, often employ spatial management as well. Here, we compare the objectives, design, and performance of spatial management in nine temperate demersal fisheries in North America, Oceania, Europe, and Africa that employ rights‐based systems. Common objectives of spatial management included protecting habitat, juveniles, and spawners and reducing discards. Recovering age structure and creating scientific reference sites were less common objectives, despite being widely cited benefits of spatial management. Some fisheries adopted single closures to achieve single objectives, whereas others adopted diverse networks to achieve multiple objectives. Importantly, many spatial protections are implemented primarily through industry initiatives. Environmental change compromised the efficacy of spatial management in some cases, suggesting the need to design spatial management systems that are robust to changing ocean conditions. Fisheries with diverse and extensive spatial management systems have generally healthier fish stocks. Whether this implies that spatial management contributed substantially to fishery performance is unclear due to an absence of large‐scale, long‐term studies aimed at discerning different drivers of success. Although these targeted monitoring studies of closed areas are limited, such studies are necessary to help resolve the ongoing debate and to enable more purposeful design of spatial management for fisheries and conservation.     

Progress in designing and delivering effective fishing industry–science data collection in the UK

This study was undertaken to address the increasing need for a strategic approach to industry–science data collections in the face of reducing resources and growing need for evidence in fisheries management. The aim was to evaluate progress in the development of plans and procedures that can be employed to collect, record and use fishing industry knowledge and data in the evidence base for managing fisheries. This was achieved by reviewing industry‐led data initiatives already undertaken or ongoing within the United Kingdom to document how these projects have/are incorporating fishing industry data into the process of management decision‐making; canvassing stakeholder opinion on data gaps and whether these could be filled by data gathered by commercial fishing vessels; establishing what issues might prevent or stimulate commercial fishing vessels in collecting data when they have the opportunity; and describing guidance on a step‐by‐step process for gathering scientific information such that fishers are empowered to collect the right data, at the right times and in the right format for their fishery. Given recent advances in the collection, interpretation and application of fisheries‐dependent data, we compare progress made in the UK to other areas of the world. We conclude that there is considerable evidence of a paradigm shift from the conventional practice of scientists asking fishers to provide data for scientific analyses towards full engagement of key stakeholders in data collection.     

Changes in life history and ecological characteristics of coral reef fish catch composition with increasing fishery management

Abstract Length, life history and ecological characteristics of landed fish communities were studied over a 10‐year period to test theories of fishing disturbance during a time of increased gear and closure management in heavily utilised fisheries. It was predicted that with greater management restrictions: (1) the earliest and fastest responses in the fishery will be seen in those species with faster turnovers, or relatively lower vulnerabilities to fishing; (2) the fishery would transition to a landed catch with higher mean trophic levels, and greater mean body lengths. In addition, the removal of a non‐selective, small‐mesh seine nets should benefit the catch of gears that previously had the greatest species selectivity overlap with the seine net. Many predictions were supported, although maximum lengths and lengths at maturity responded more rapidly than anticipated. The response to eliminating the non‐selective seine net was a more rapid increase in sizes caught by gears with a larger overlap in size (hook and lines) than species selectivity (gill nets). The simultaneous comparison of management systems over time indicates that open‐access fishing grounds can benefit from restrictions imposed in adjacent fishing grounds. The study indicated that multi‐species coral reef fisheries management objectives of maximising yields, as well as maintaining the fish community’s life‐history diversity, require management trade‐offs that balance local socio‐economic and biodiversity needs.     

Changes in a coral reef fishery along a gradient of fishing pressure in an Indonesian marine protected area

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Disturbance of benthic species by fishing activities: a sensitivity index

1. Preliminary estimates of the relative sensitivity of sea bed types and benthic species to physical disturbance, particularly fishing activity, have been made in order to identify areas where further studies are required and to help formulate management plans for sites of marine conservation importance. 2. Physical disturbance is considered in the context of a single encounter with fishing gear followed by a recovery period during which there is no fishing, but with a view to qualifying, in the future, the effect of multiple fishing events. Disturbance is considered in terms of the physical action of the gear on the sea bed and the unit area over which this action occurs. 3. The effects of a wide range of gears are considered. Static gears, which can be employed on a variety of substrata, generally result in low level impacts for single fishing events and impacts are localized compared with the effects of mobile gears, which can extend over considerable areas. 4. The theoretical sensitivity of individual species is assessed on the basis of how well they cope with an encounter with fishing gear and on their likely recovery from destruction in terms of their reproductive strategies. 5. Species considered of key importance in the structuring of communities are suggested and examples of particularly sensitive species, which are therefore likely indicator species of physical disturbance, are listed. 6. Fragile, slow recruiting animals are considered to be most susceptible to disturbance, while the least sensitive species are generally fast growing and have good recruitment. ©1996 by John Wiley & Sons, Ltd.     

Could the obligation to land undersized individuals increase the black market for juveniles: evidence from the Mediterranean?

The latest Green Paper on the EU Common Fisheries Policy (CFP) identified the high level of discards in Europe as one of the structural weaknesses of the current CFP. The new CFP introduces a discard ban in European waters, with an obligation to land all regulated species. The fishing management system in the Mediterranean is based on effort control and technical measures, and this is raising some particular concerns about the effective implementation of the discard ban. With the exception of bluefin tuna (Thunnus thynnus, Scombridae), there are no quotas in the Mediterranean and this regulation affects all regulated species with the minimum landing size. Under these circumstances, the discard ban may lead to an increase in the amount of juvenile fish caught, because such catches are not counted against a given quota, as is the case in the Atlantic fisheries, and thus, there is no incentive to avoid catching them. On the contrary, the obligation to land the juveniles that are now discarded and their subsequent fishmeal processing might even become commercially interesting. One possible consequence of the new regulation may be an increase in the illegal marketing of fish below the minimum size. The landing, storage and transportation of juveniles will all be legal, and this may simplify their commercialization via the black market. The discard ban and landing obligation should be accompanied by other measures to ensure their successful implementation, including the agreement of the fishing sector to comply with the rules and regulations.     

Keeping watch on the unwatchable: technological solutions for the problems generated by ecosystem-based management

Ecosystem‐based management is an emerging paradigm influencing the management of commercial fisheries. Increasingly, developed nations are adopting explicit legislation and policy governing the assessment and management of their fisheries against criteria of ecological sustainability. Yet the ability to evaluate ecosystem impacts of fisheries is compromised by a general lack of understanding of marine ecosystem function (beyond the population level) and a lack of robust and practical indicators for ecosystem health and management. Recent technological advances can assist in developing criteria, including structural analyses of seafloor communities potentially impacted by fishing gears (e.g. demersal trawling). Similarly, advances in fishing gear technology, including improved selectivity and the development of gears which have a more benign environmental impact, can mitigate some of the ecological impacts of fishing. Such technological advances are summarized in the context of contemporary fisheries management.     

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福建省内陆捕捞渔具的作业类型及其数量组成分析

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Thirty years of fleet dynamics modelling using discrete‐choice models: What have we learned?

Anticipating fisher behaviour is necessary for successful fisheries management. Of the different concepts that have been developed to understand individual fisher behaviour, random utility models (RUMs) have attracted considerable attention in the past three decades, and more particularly so since the 2000s. This study aimed at summarizing and analysing the information gathered from RUMs used during the last three decades around the globe. A methodology has been developed to standardize information across different studies and compare RUM results. The studies selected focused on fishing effort allocation. Six types of fisher behaviour drivers were considered: the presence of other vessels in the same fishing area, tradition, expected revenue, species targeting, costs, and risk‐taking. Analyses were performed using three separate linear modelling approaches to assess the extent to which these different drivers impacted fisher behaviour in three fleet types: fleets fishing for demersal species using active gears, fleets fishing for demersal species using passive gears and fleets fishing for pelagic species. Fishers are attracted by higher expected revenue, tradition, species targeting and presence of others, but avoid choices involving large costs. Results also suggest that fishers fishing for demersal species using active gears are generally more influenced by past seasonal (long‐term) patterns than by the most recent (short‐term) information. Finally, the comparison of expected revenue with other fisher behaviour drivers highlights that demersal fishing vessels are risk‐averse and that tradition and species targeting influence fisher decisions more than expected revenue.     

Drones detect illegal and derelict crab traps in a shallow water estuary

The issues surrounding illegal, unregulated and unreported fishing, and that of abandoned, lost and discarded fishing gears, leading to ghost fishing, are intensifying. Estuarine crab trapping is likely subject to high levels of illegal and potential ghost fishing, because it also has good economic incentives regarding potential catch, low gear acquisition costs and accessible fishing grounds. To improve the efficiency and effectiveness of fisheries monitoring, control and surveillance operations, the efficacy of small consumer‐grade drones for sighting traps in an estuary in NSW, Australia, was tested. Twelve sets of two flights were undertaken at 20 and 30 m altitude over a 600‐m stretch of estuary for 5 days to quantify the detectability of submerged mesh traps of three different mesh colours. The drone was able to detect the majority of traps efficiently, with depth in relation to water clarity being the main factor affecting detection. In shallow water, detection rates were high for all mesh colours, but in the slightly deeper placements, orange traps were more readily detected. This study demonstrates that drones could be an efficient and reliable tool for rapidly assessing areas for illegal and derelict traps and can be supplemented into land or vessel‐based fisheries operations.