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1.
One of the reasons for the failure of some Marine Protected Areas (MPAs) is the lack of respect for their boundaries and regulations, which intensifies the need to assess the attitudes of stakeholders affected by MPAs. To this end, it is necessary to know the perception and behavior of resource users in these areas in relation to the management process. This study addressed the perception of different groups of fishermen in three MPAs that allow sustainable use of resources on the Brazilian northeastern coast. The perception analysis was based on four aspects: biodiversity conservation, flexibility and adaptability of fishermen, participation in management and opinions about the MPA. The interviewed fishermen (n=100) were classified into natives or immigrants,≥than 40 years old or <40, predominant use of selective or nonselective fishing gear and part or full time fishermen. The results showed that younger fishermen and the ones who use selective fishing gear presented a more conservation prone perception; nonselective fishermen and part-time fishermen were more flexible and adaptable to changes; and younger fishermen tended to agree more with the establishment of the MPAs. Taking these differences in perceptions among fishermen into account could serve as a basis for improvements in the management and conservation of fishing resources, besides helping predict possible future behavior due to changes in management policies.  相似文献   

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3.
No-take marine protected areas (MPAs), where all fishing is prohibited, have been shown to provide benefits that include greater productivity of fish stocks due to increased densities, average sizes, and reproductive output. A critical component of this success is the effective management of MPAs to ensure that only those activities deemed permissible, are allowed to occur. As of 2008, 161 MPAs had been designated on the Pacific coast of Canada by federal, provincial or municipal authorities. The objective of this study was to discover how many of these MPAs are intended to provide full protection to habitats and species from commercial fishing and whether management measures were put in place to actualize this conservation intent. The comprehensive spatial dataset was built illustrating commercial fisheries closures and this was overlaid with MPA locations in a GIS. The majority of MPAs were designated as IUCN Strict Nature Reserve (Type Ia), Wilderness Area (Type Ib), and National Park (Type II) marine reserves, which are intended to be free from exploitation. It was found that 160 of the 161 MPAs are open to some commercial harvesting within their bounds. One small municipal MPA and portions of three other MPAs are not open to commercial harvesting. The incongruence between management intent and fisheries permitted suggests a management failure between designation of MPAs and implementation of fisheries management regulations.  相似文献   

4.
Although an important conservation tool, Marine Protected Areas sometimes fall short of intended goals; however, adaptive management can potentially improve their effectiveness. Efforts to develop an MPA in Gilbert Bay, Labrador, Canada, began in 1998 to protect the genetically distinct population of Atlantic cod (Gadus morhua) and its habitat. Population monitoring and research conducted in Gilbert Bay during 26 research trips over 14 years have documented significant population declines. The biomass declined by as much as 83% and research catch rates by 54% since Gilbert Bay became a MPA in 2005. Commercial fishing in adjacent waters was strongly correlated (Pearson correlation r=−0.87, p=0.002), with the declining trend in research catch rates. Tag recaptures from the commercial fishery (n=105) confirmed that fishing removed large adult Gilbert Bay cod that seasonally move outside the MPA. Evidence of the production of strong year classes even at low adult population levels indicate that the Gilbert Bay cod population has the potential to increase rapidly under appropriate adaptive management; thus improving MPA effectiveness. A relatively small change in the timing of commercial fishing in waters adjacent to the MPA would likely produce this result; however, inflexible MPA regulations, and poor co-ordination and agreement among differing fishery management processes and stakeholders has delayed the implementation of such a change.  相似文献   

5.
As marine protected areas (MPAs) continue to be established, measures to address displaced effort are likely to become increasingly relevant. Recent experiences of displaced fishing effort programs for MPAs and recreational fishing reserves in Australia, together with two examples from the United States, are described. A practical framework for addressing displaced fishing effort is developed, which explores the likely displaced-effort scenarios and options when planning spatial commercial fishing closures for an MPA.  相似文献   

6.
The European common fisheries policy (CFP) advocates measures to sustain small-scale fisheries; hence, in the European Commission's proposal for a reformed CFP, these are exempted from a mandatory system with tradable fishing concessions. This opens up for management actions designed for small-scale fisheries, but also implies new management issues. This article provides insights into the topic based on a Swedish small-scale herring fishery in the western Baltic Sea that was exempted from an ITQ-system. The fishery has been profitable since the system was introduced, and the increasing effort of both incumbent fishermen and new entrants implies a situation where fishermen compete for a limited quota. The migratory pattern of the herring implies high densities in the southern parts of the fishing areas during spring and in the northern parts during autumn. This forms the basis for two different fisheries in the area, as well as for the current management proposal to divide the quota into a spring and an autumn part. This and other management proposals are discussed in the paper. The main conclusion from the case study is that, when exempting a fishery from tradable fishing concessions, it is important to build other institutions dealing with the fundamental problem of access to the quota. Failure to do so might result in an over-capacity issue and threaten the long-run development of an otherwise successful small-scale fishery.  相似文献   

7.
A dynamic one-dimensional model of Marine Protected Areas (MPAs) along a coastline has been developed to investigate their impact on fish stocks and landings over time. The model is basically a cellular automaton implemented with a spreadsheet and is used to trace stocks and landings from the initiation of the MPA for several years under a set of three different scenarios for the allocation of fishing effort. In all cases landings decline as soon as part of the coastline is protected, but in every case they recover to their original level and above. The time it takes for landings to recover ranges from four to nine years and with two small MPAs (several small) the recovery is faster than with one large one of the same spatial extent (single large). These results indicate that although fishery closures through an MPA will undoubtedly have an immediate adverse impact on the fishing industry, the chances of full recovery after several years are good, and both the fishery and the fish stocks will benefit in the long run. Further, our model provides a null model on the impacts over time of MPAs that may iteratively be compared with real cases that have biological and social variables.  相似文献   

8.
资源评估是应用各种统计和数学方法量化地于业种群形态对渔业管理选择的反应。资源评估不仅仅是预测静止的最佳捕捞努力量和持续产量,而是评估鱼类和渔民对管理决策和其它变化的动态反应。在动态的渔业系统中帮助管理者进行决策是一个困难的任务,资源评估生物学家要配合管理者和决策者提出适当的问题,和思考渔业对变化的动态反应。  相似文献   

9.
The Eastern Baltic cod stock was until recently below safe biological limits and suffered from high fishing pressure. In most recent years, fishing mortality substantially declined and spawner biomass more than tripled. Similar developments have not been observed for any other depleted cod stock in the North Atlantic during the last few decades. This paper investigates relative impacts of changes in different ecological and management-related drivers, which could have contributed to the rapid recovery of the Eastern Baltic cod. The results show that the success to reduce fishing mortality below management target in 2008 was due to a combination of increased recruitment and improved compliance with TAC. The reversal of the negative trend in biomass and rebuilding of the stock to the present level were largely driven by increased recruitment. Harvest control rules of the multi-annual management plan for setting TACs currently maintain the fishing mortality at a low level, which allows the stock to accumulate biomass and further accelerate its recovery. Relatively strong incoming year-classes and recently better control over removals distinguish the Eastern Baltic cod from other depleted European cod stocks, which have not shown similar positive trends in recent years. Sound management measures and compliance to those as well as favourable biological conditions are required for a successful stock recovery.  相似文献   

10.
The Northern Gulf of California is an area important for small-scale fisheries in terms of economic activity and food security, but widespread non-compliance with fisheries regulations impedes effective management of resources and conservation efforts. Where a previous study evaluated quantitatively a theoretical situation in which all regulations are perfectly followed, this article compares a suite of recently proposed ecosystem-based management (EBM) policies against the expected benefits of full enforcement of current regulations. Policies evaluated include no-take marine protected areas (MPAs), breeding period closures, changes in hook size and fishing effort, and gear-specific spatial closures. No-take MPAs yield ecological benefits over a wide range of MPA sizes and characteristics, but do not increase overall catch. Seasonal closures are effective at reducing overfishing for the depleted leopard grouper (Mycteroperca rosacea); changing the hook size of artisanal longlines does not increase catch of either the target species or the assemblage, and gear-specific fishery closures for crab traps near Puerto Peñasco are effective at reducing overfishing of blue crab (Callinectes bellicosus and C. arcuatus). In general, full enforcement of existing regulations outperforms these EBM policies in terms of conservation benefits, but it may be less palatable to stakeholders as it requires major reductions in catch.  相似文献   

11.
《Marine Policy》2005,29(5):407-420
Excessive overfishing combined with negative environmental conditions led to the decimation of the northern cod stock and its closure to commercial fishing in 1992. During the ensuing dozen years, the stock has not recovered. This paper considers the current state of the Newfoundland economy and the Newfoundland fishery and asks whether the lessons of the earlier day have been learned. The answer appears to be no. The main mover of the economy is exogenous to the fishery, the unemployment rate remains high, currently more than twice the Canadian rate, and the population of the province has fallen by ten percent. With respect to the fishery, although the decimated groundfish have been replaced by shellfish and the nominal value of landings has doubled since 1992, the fishery still has excess capacity, fishermen and fish plant workers generally earn low incomes, and the fishery remains heavily subsidized.  相似文献   

12.
Standardised sampling protocols for monitoring fish stocks are essential to assess changes in stock status and provide a means to evaluate the effectiveness of fisheries management measures, such as marine protected areas (MPAs). This study aimed to optimise two standard sampling methods, namely underwater visual census (UVC) and controlled angling, for assessing subtidal reef fish communities. In terms of efficiency, variability and bias, UVC transects were found to be superior to point counts. For controlled angling, an effort of two angler-hours per fishing station provided low catch variability, high catch per unit effort and a representative catch. Whereas UVC provided less variable estimates of relative density, controlled angling provided greater sampling efficiency. It is thus recommended that the two methods be used in conjunction. The optimal sampling protocols identified are suitable for rapid assessments or long-term monitoring of subtidal, temperate reef fish communities.  相似文献   

13.
For decades, fishermen in most parts of the world have been experiencing a reduction in fish abundances. Overexploitation and increasing demands are the glaring visible causes, but weakness or absence of fishery management is the core problem. Faced with repeated failure of fishery management and the resulting overexploitation in fish stocks, new management plans are needed in order to preserve both fishermen's jobs and food security. A growing number of published sources have proposed marine protected areas (MPA) as a fishery management tool. The decision of MPA design requires close collaboration with local fishermen communities for it to be accepted and respected. This paper focus on the case of a Uruguayan lagoon, the Rocha lagoon, which is exploited by two fishermen communities. The lagoon is located inside a national park. Park authorities are in the process of designing a management plan that defines a MPA inside the lagoon. The plan also sets out the rules to be upheld for the artificial opening of the sandbar that separates the lagoon from the ocean. It is shown that it is relevant to study the local ecological knowledge (LEK) in order (1) to understand the fishery related ecological issues within the lagoon and (2) to highlight an existing conflict between two fishermen communities. Studying the LEK allowed a clear representation of the factors that must be taken into account when defining the management plan. Furthermore, the LEK study in itself creates an appropriate place for inter-community debate and it enhances the acceptance of the future management plan.  相似文献   

14.
Up to one-third of commercial fishery stocks may be overfished at present. By analyzing catch trends and applying an empirical relationship derived from stock assessments, this article tracks the geographic spread of overfishing at the country level in terms of lost catch and lost revenue, from the start of industrialized fishing in 1950-2004. The results tell a cautionary tale of serial depletion to meet the ever-rising demand for fish. Examining country losses with respect to fishery management reveals that overcapacity and excess fishing effort are widespread, but also that recent trends towards sustainability can stabilize or reverse losses (e.g. for Norway, Iceland, the US, Canada, Australia, and New Zealand). Global trade effectively masks the successive depletion of stocks, so that without decisive action to reduce fishing effort, many more stocks will suffer and undernourishment impacts for the major exporting, food-deficit nations will only magnify.  相似文献   

15.
《Ocean & Coastal Management》2006,49(5-6):342-354
Marine protected areas (MPAs) have become a common conservation and management tool for reducing exploitation from the commercial and recreational fisheries sectors. However, the recreational fisheries sector has the potential to be compatible with no-take MPAs when catch-and-release angling is practiced because, in theory, no fish are actually harvested. This presumes that the effects of catch-and-release angling and related activities do not cause appreciable declines in fish populations as a result of direct mortality, sub-lethal effects, or indirect effects on fish habitats, or other problems contrary to the goal of a given MPA. Here, we explore the idea that recreational catch-and-release angling may be compatible with some no-take MPAs provided there are no substantive negative ecological consequences. We argue that it is not currently possible to answer definitively the question of whether recreational catch-and-release fisheries can be compatible with no-take MPAs. Mortality rates of released fish vary extensively (between zero and near 100%) and are influenced by a number of factors including environmental conditions, fishing gear, angler behavior, and species-specific characteristics. Nevertheless, research in the field of catch-and-release is beginning to show that certain handling techniques can significantly reduce post-release mortality in fish. With appropriate regulation and angler education, catch-and-release could help enhance conservation and management goals associated with MPAs while maintaining public support and providing alternative tourism-based revenues for displaced fishers. Until sufficient data are available, research should focus on contrasting the fish community characteristics in regions with no fishing and those that permit catch-and-release fishing (i.e., opportunistic observations and controlled manipulations) as well as population-level mathematical modeling to assess the effects of angling on long-term population viability and ecosystem dynamics. Additional efforts should focus on education and outreach that provide anglers and fishing guides with the best available information to reduce catch-and-release mortality, sublethal angling-induced impairments, and broader effects on aquatic environments.  相似文献   

16.
In the North Atlantic the Icelandic, the North Sea, and the Newfoundland cod stocks are currently overexploited. Overexploitation also characterised the Northeast Arctic cod stock, but effective management measures introduced in 1990 and the years thereafter have brought this stock within safe biological limits. The Northeast Arctic cod stock is transboundary and shared between Norway and Russia. As guidelines for a sound management strategy of this cod stock in the future, reference points for management are discussed. As a point of departure, a management strategy which fulfils the objectives for fishery policy stated by Norway is analysed. These objectives, focusing on sustainable harvesting, increased profitability and the role of the fishery as employer of labour in rural districts are fundamental in most of the world's fishery nations.The “optimal” strategy is defined as the one which fulfils these in the best way possible. The natural variations are discussed and the biological and economic yield's dependence upon the rate of exploitation are analysed. The analysis shows that the size of the spawning stock should be no less than 500 000 tonnes and that highest yield is obtained through a rate of exploitation of around 17–30% (equivalent to a fishing mortality of about 0.20–0.40). A spawning stock size of 500 000 tonnes should therefore serve as a “limit reference point” and a fishing mortality of about 0.20–0.40 should serve as a “target reference point” in the management of Northeast Arctic cod.The method described may be applied to other demersal stocks to help establish target and limit reference points in order to conduct a sound management.  相似文献   

17.
In 1998, in order to combat the degradation of yellow tang populations on the west coast of Hawaii Island, fish replenishment areas (FRAs) were established prohibiting aquarium fishing along more than thirty percent of the coastline. Unlike other marine management approaches in Hawaii, which have largely been controversial, fraught with confusion over regulations, inadequately enforced, and lacking public support, these FRAs have been lauded as a marine conservation success, with wide-ranging support and evidence of rapid replenishment of the yellow tang population. In order to better understand the contextual factors contributing to the success of the West Hawaii FRAs, this research explores the following questions: (1) What factors documented in the literature on marine protected areas (MPAs) have been demonstrated to contribute to or inhibit MPA success internationally; (2) which of these factors do the FRAs of West Hawaii exhibit; and (3) are there additional factors that may have contributed to their wide acceptance and success? Common factors contributing to MPA success are determined through a synthesis of the literature. These include: level of community engagement, socioeconomic characteristics, ecological factors, MPA design, governance, and enforcement. The outcomes of West Hawaii′s FRAs are examined in the context of these factors. While the common factors agreed upon in the literature were key to the success of the FRAs, additional contextual factors such as the unique nature of the aquarium fishery and its social marginalization also played a vital role.  相似文献   

18.
Marine protected areas (MPAs) are a global conservation and management tool to enhance the resilience of linked social-ecological systems with the aim of conserving biodiversity and providing ecosystem services for sustainable use. However, MPAs implemented worldwide include a large variety of zoning and management schemes from single to multiple-zoning and from no-take to multiple-use areas. The current IUCN categorisation of MPAs is based on management objectives which many times have a significant mismatch to regulations causing a strong uncertainty when evaluating global MPAs effectiveness. A novel global classification system for MPAs based on regulations of uses as an alternative or complementing the current IUCN system of categories is presented. Scores for uses weighted by their potential impact on biodiversity were built. Each zone within a MPA was scored and an MPA index integrates the zone scores. This system classifies MPAs as well as each MPA zone individually, is globally applicable and unambiguously discriminates the impacts of uses.  相似文献   

19.
Since 2002, 5.3% of the Victorian coastal waters have been declared as Marine Protected Areas (MPAs). These are aimed at safeguarding important marine habitats and species, significant natural features, and areas of cultural heritage and aesthetic value. However, MPAs impact the fishery for southern rock lobster (Jasus edwardsii), as total allowable catches (TACs) were previously set to allow the biomass to recover to pre‐specified target levels. The model on which assessments and risk analyses are based is extended to include the impact of MPAs. The MPAs and the area open to fishing are modelled as subpopulations with different levels of mortality and consequently different density and population size‐structure. A range for the probability of a lobster moving from a MPA to the fished area from 0 to 15% is considered, based on the results of tagging studies. The reduction of biomass available to the commercial fishery because of the introduction of MPAs is estimated to be 8% and 16% (Western and Eastern Zones) respectively. The results of a risk assessment show that if the current TACs are maintained, the time to increase the biomass available to the commercial fishery by 50% would be delayed 5–9 years in the Western Zone and 1–4 years in the Eastern Zone because of the impact of displaced effort. In contrast, spawning biomass in the Eastern Zone is currently below the agreed limit reference point, and the introduction of MPAs would enhance the rate of recovery, although only marginally initially, faster than the absence of the MPAs.  相似文献   

20.
Management strategies are challenging to implement in Zanzibar's fisheries because the local people depend upon these resources for basic subsistence. This difficulty epitomizes the vital need for sustainable management: the more people need a fishery, the harder it is to limit fishing to allow regeneration. Comparing fisheries management strategies in two coastal villages in Unguja, the largest island of Zanzibar, Tanzania, this paper confirms the results of existing scholarship that communitybased strategies provide the most promising solutions to this challenge. Interviews with officials from the Department of Fisheries and Marine Resources, Village Fishermen Committees, and 51 fishermen in the villages of Kizimkazi Dimbani and Jambiani reveal the efficacy of strategies where local fishermen are centrally involved. The fishermen interviews reveal ignorance of existing fishing regulations and a lack of enforcement while fishermen at both sites noted that many illegal methods of fishing are still in use and expressed concern that such methods damage fish stocks. The Village Fishermen Committees, a recently implemented community-based initiative, are well attended by fishermen, and constitute a management strength that this paper concludes should be the foundation of future policy. To be successful, these committees need additional educational and financial resources.  相似文献   

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