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1.
Fishermen, scientists, national policy makers, and staff of environmental NGOs (ENGOs) hold different perceptions about temporal patterns in fish stocks. Perception differences are problematic in multi-stakeholder settings, because they elicit controversies and unbalanced disputes. These hinder effective participation, a prerequisite for ‘good governance’ and effective management of sustainable fisheries. This study shows that perceptions of change (‘does the stock increase or decrease?’) and of current status of a fish stock (‘is it doing well or not?’) are influenced by the capturing and processing of information, rather than by interests alone. We focused on the Dutch North Sea fishery on plaice and sole and examined (1) availability and accessibility of information on temporal patterns of these stocks and (2) perception differences between all parties. A first explanation for these differences is the use of different parameters as a measure for stock size. Fishermen focus on catch rates or catch-per-unit-effort (relative stock size), whereas scientists, policy makers, and ENGO-staff mainly use scientific assessments of spawning stock biomass (absolute stock size). Between-group perception differences are further explained by spatial aggregation levels of information, lengths of time series evaluated, and by modes of comparison to qualify the current status of fish stocks. Awareness of information differences and the development of shared information use and processing may release some of the tensions in multi-stakeholder settings debating fisheries management. However, comprehension problems amongst all parties on how spawning stock biomass is reconstructed and how it relates to catch rates in the fishery may pose an enduring barrier. 相似文献
2.
Contemporary fish provisioning, in the era of globalization, is linking distant locations through the catchments and consumption of fish, and as more and more fish stocks are coming under threat there are unprecedented challenges emerging for environmental governance. The conventional nation-state-based regulatory arrangements of the past are becoming inadequate and in response alternative arrangements emerge. This article will compare two of these innovative fish governance arrangements addressing problems of sustainability, notably the Marine Stewardship Council and the WTO. This comparison provides support for the claim that environmental governance of global fish provision puts the traditional notions of ownership and sovereignty under pressure, while simple alternative governance arrangements are not (yet) available. 相似文献
3.
G. D. James 《新西兰海洋与淡水研究杂志》2013,47(3):229-240
Cod‐end mesh selection experiments were conducted on three species of flatfish (common or English sole Peltorhamphus novaezeelandiae, lemon sole Pelotretis flavilatus, and sand flounder Rhombosolea plebeia) trawled off the Otago coast. It is suggested that better yields would be obtained from stocks of these fish if the minimum cod‐end mesh size was increased from 10.2 cm (4 in.) to 11.4 cm (4.5 in.). 相似文献
4.
《Marine Policy》2013
Small pelagic fish like sardine, anchovy and herring feed on zooplankton and are in turn prey for fish higher up in the food chain. They are therefore expected to play a vital role in transfer of energy between levels in the food chain. Some stocks of small pelagics are extremely large and subject to very substantial fluctuations caused by environmental factors. They are also very vulnerable to exploitation due to schooling behavior and highly efficient fishing technology. Several such stocks crashed in the 20th century as a result of heavy exploitation and/or adverse environmental changes. The effect of four such stock crashes on other fisheries are reviewed and found to be limited or nonexistent. This puts into perspective a recent report from the Lenfest Foundation, which examines small pelagics and their role in the ecosystem and finds that certain sea bird populations have been severely affected by exploitation of small pelagics. The report recommends more conservative management of small pelagics to limit the effects on predators, but makes no effort to weigh this against the contribution of forage fish to food production. 相似文献
5.
Exploited fish and shellfish stocks in European marine waters underlie the Common Fisheries Policy (CFP). The next round of reform of the CFP is due for completion in 2012. The exploitation at maximum sustainable yield (MSY) may be confirmed as the common environmental objective for good environment status (GES) of exploited fish and shellfish stocks of the reformed CFP and the Marine Strategy Framework Directive (MSFD). The foreseen time horizon to achieve or maintain GES by 2020 appears inconsistent with the World Summit on Sustainable Development UN agreement in 2002, which stipulates that maintenance or restoring of stocks to produce MSY be realized by 2015. The MSFD requires instead that by 2015 the national programmes of measures be designed in order to become operational the following year (2016). 相似文献
6.
We developed an ageing methodology and examined age composition of three flatfish stocks inhabiting the Seto Inland Sea, Japan. Ages were difficult to determine for three-lined tongue sole (Cynoglossus abbreviates) and ridged-eye flounder (Pleuronichthys cornutus) because the first year annulus ring was often indistinct; therefore, we used directional change in otolith growth to distinguish it. Sectioning and etching methods were powerful tools for identifying annual checks for red tongue sole (Cynoglossus joyneri). Using these ageing methods, we determined age–length relationships and growth curves. The age composition of the populations studied and of the landings showed that a large proportion of the latter consisted of individuals under the mean age of sexual maturity, thereby reducing the percent spawning potential ratio (%SPR) to ≈ 20% for all species. These findings suggest that fishing pressure on immature fish is leading to overfishing of these flatfish stocks. 相似文献
7.
JN Kathena A Kokkalis MW Pedersen JE Beyer UH Thygesen 《African Journal of Marine Science》2018,40(3):293-302
There is global interest in providing scientific advice on optimal harvesting of all commercially exploited fish stocks. Nevertheless, many commercially important stocks lack analytical assessments. Therefore, we evaluate a data-moderate stock assessment method: the stochastic surplus production model in continuous time (SPiCT). The method was applied to two Namibian stocks: (i) the data-rich Cape monkfish Lophius vomerinus, where results are compared to a new data-rich assessment using a state–space assessment model (SAM); and (ii) the data-moderate west coast sole Austroglossus microlepis, which is an important bycatch species in the Cape monkfish fishery, but currently unassessed. The information available to the data-moderate assessment is total commercial catch, commercial catch per unit effort (CPUE), and survey CPUE. SPiCT and SAM gave largely consistent estimates of relative fishing mortality (F/FMSY) and relative exploitable biomass (B/BMSY) for the Cape monkfish stock, although with some discrepancies. Differences in the biomass estimates between the two assessments suggest that further investigation is required to understand the cause, and that some caution is necessary when considering the biomass of the stock. SPiCT shows that the west coast sole may be overexploited, although the confidence bounds were too wide for a firm conclusion. Similarity in the estimates of F/FMSY for Cape monkfish in recent years, using SPiCT relative to SAM, likewise indicates the suitability of SPiCT for managing west coast sole. 相似文献
8.
《Journal of Sea Research》2011,65(4):451-456
We developed an ageing methodology and examined age composition of three flatfish stocks inhabiting the Seto Inland Sea, Japan. Ages were difficult to determine for three-lined tongue sole (Cynoglossus abbreviates) and ridged-eye flounder (Pleuronichthys cornutus) because the first year annulus ring was often indistinct; therefore, we used directional change in otolith growth to distinguish it. Sectioning and etching methods were powerful tools for identifying annual checks for red tongue sole (Cynoglossus joyneri). Using these ageing methods, we determined age–length relationships and growth curves. The age composition of the populations studied and of the landings showed that a large proportion of the latter consisted of individuals under the mean age of sexual maturity, thereby reducing the percent spawning potential ratio (%SPR) to ≈ 20% for all species. These findings suggest that fishing pressure on immature fish is leading to overfishing of these flatfish stocks. 相似文献
9.
捕捞和气候变化在南海北部湾口鱼类长期种类演替和种群动态的作用 总被引：2，自引：0，他引：2
捕捞压力在改变南海鱼类种类演替和生物量波动方面所起的作用大于气候和环境因素是一个普遍的、有争议的假设。根据1959~2010年南海北部北部湾口底拖网的调查数据，报告了该海域鱼类种类组成、优势类群的丰度比例、生物量的季节和年际变化。建立了鱼类生物量与捕捞压力和气候变化外部因素之间的广义加性模型。结果表明，捕捞压力驱动底层渔业资源急剧下降的主要因素，并随着时间的推移，高值鱼类被低值鱼类所取代。1993年和1998年期间鱼类生物量的突然减少与同期厄尔尼诺事件相对应，气候变化可能是渔业拖网捕捞中中上层鱼类比例变化的主要驱动因素。为了更好地了解鱼类群落动态，需要区分捕捞压力和环境驱动因素对不同生活史策略鱼类物种的影响。 相似文献
10.
Concern has been raised over whether environmental release of alkylphenols (AP) in produced water (PW) discharges from the offshore oil industry could impose a risk to the reproduction of fish stocks in the North Sea. An environmental risk assessment (ERA) was performed to determine if environmental exposure to PW APs in North Sea fish populations is likely to be high enough to give effects on reproduction endpoints. The DREAM (Dose related Risk and Effect Assessment Model) software was used in the study and the inputs to the ERA model included PW discharge data, fate information of PW plumes, fish distribution information, as well as uptake and elimination information of PW APs. Toxicodynamic data from effect studies with Atlantic cod (Gadus morhua) exposed to APs were used to establish a conservative environmental risk threshold value for AP concentration in seawater. By using the DREAM software to 1) identify the areas of highest potential risk and 2) integrate fish movement and uptake/elimination rates of APs for the chosen areas we found that the environmental exposure of fish to APs from PW is most likely too low to affect reproduction in wild populations of fish in the North Sea. The implications related to risk management of offshore PW and uncertainties in the risk assessment performed are discussed. 相似文献
11.
《Marine Policy》2017
The management and governance of shared stocks have long been identified as a challenge to achieve long-term sustainability in fisheries. This is the situation of fisheries in the Amazon basin, a region shared by nine countries. This paper provides an overview of the social-ecological outcomes and management implications of sharing fish stocks among countries with different public policies, taking the valuable Amazonian ornamental silver arawana (Osteoglossum bicirrhosum) trade as a case study. Specifically, it (i) presents and discusses the policies of Colombia, Peru and Brazil for the silver arawana fishery, and how these are conducive for the successful management of this shared transboundary fishery; and (ii) analyzes the market for the ornamental silver arawana and how it affects the ability to sustainably manage the fishery. The interplay between the multiple environmental, economic and social dimensions involved in the ornamental silver arawana fishery affects the sustainability of this species even in Brazil, where this fishing is forbidden but still illegally caught by Colombians and Peruvians. Among the factors that make fisheries policies inefficient in this region are: (i) incongruent policies between the countries and institutions with low organizational capacity to accomplish the established policies; (ii) environmental heterogeneity of Amazonian aquatic systems, which requires local and adaptive measures; and (iii) complex socio-economic relationships in the live-fish trade business. Legally binding efforts to reduce problems derived from shared fish stocks are an urgent need and should be addressed by the multilateral organizations created for the Amazonian sustainable development. 相似文献
12.
Phenotypic traits such as peak spawning time may vary within and differ between populations in relation to environmental factors, such as temperature. Sole (Solea solea) is a valuable, commercially exploited species that spawns in late winter or spring. The date of peak spawning was estimated for each year for seven stocks from monthly fish samples collected from commercial fisheries since 1970. Four out of seven stocks showed a significant long-term trend towards earlier spawning (Irish Sea, east-central North Sea, southern North Sea, eastern English Channel) at a rate of 1.5 weeks per decade. The other three stocks (Bristol Channel, western English Channel and western-central North Sea) failed to show a relationship, but the available time series were limited for these stocks (< 10 years). Sea surface temperature during winter significantly affected the date of peak spawning, although the effect differed between stocks. The implications of the effect of winter temperature on the timing of spawning for the population dynamics are discussed. 相似文献
13.
《Marine Policy》2014
Korea's coastal and offshore fisheries have experienced reduction in their catch in the early 2000. The amount of catch from coastal and offshore fisheries dropped from 1.7 million tons in 1986 to 1 million tons in 2004. To address such catch reduction, fish stock enhancement programs have been constantly developed and implemented. However, as fish stocks have been estimated to decrease since 2000 in spite of various management measures, the Korean Government genuinely acknowledges the necessity to enhance fisheries productivity through the recovery of depleted fish stocks. Based on such acknowledgement, a fish stock rebuilding plan (FSRP) combined with conventional fish stock enhancement programs was established in 2005. For stocks which have shown drastic decrease, a FSRP was set up and promoted. So far, 10 FSRPs have been established and operated, and plan is being made to expand them to 20 species by 2012. The result of pilot projects shows that stocks have been increasing after the introduction of FSRPs. For instance, the catch per unit effort (CPUE) of sandfish in the East Sea has increased from 0.44 in 2005 to 0.78 in 2011. Consequently, fishing income has increased by 15%. The key lessons learned during the implementation of FSRP are: the causes for the decrease of stock vary and are complicated and it is necessary to adjust and eliminate some conventional policies that could have unforeseen negative impacts on fish stocks. The FSRP-based fisheries management policy in Korea carries great significance, for it has changed the focus of policy from simply maintaining the status quo to stock recovery and it allows relevant stakeholders to get actively involved in the procedures of establishing and promoting the plan, leading to effective implementation of the plan. The current FSRP is operated with species, but if it can be gradually expanded to encompass the whole ecosystem, it will greatly contribute to more effective management and fish stock recovery for all species in offshore and coastal waters surrounding Korea. 相似文献
14.
According to the 1995 United Nations Fish Stocks Agreement (UNFSA), straddling fish stocks and highly migratory fish stocks are to be managed by Regional Fisheries Management Organisations (RFMOs), consisting of coastal states and relevant Distant Water Fishing Nations (DWFNs). In the North East Atlantic there are several straddling stocks, including herring, mackerel, blue whiting, redfish and numerous deep sea stocks that are exploited both within coastal states’ 200 mile Exclusive Economic Zones and on the high seas. Management of such stocks poses special management problems. In this area, the North East Atlantic Fisheries Commission (NEAFC) represents the relevant RFMO. So far the literature has devoted little attention to RFMOs in general and to NEAFC in particular. The purpose of this report is, first, to provide an overview of the organisation, structure, and objectives of NEAFC and, second, to consider its performance with regard to resource management. 相似文献
15.
《Marine Policy》2016
One of the main challenges of international environmental agreements is improving relevant policy actions to promote adequate environmental responses. To support the work of decision makers, recent studies have used environmental and social indicators to construct global and regional-scale indices. This study aimed to use the Ocean Health Index and the Management Ranking for Brazilian States to assess Brazil’s performance regarding the Aichi Biodiversity Targets (ABTs) for coastal and marine ecosystems. Thus, six ABTs were matched and their performance was evaluated. These ABTs focused on the following topics: pollution, fish and invertebrate stocks, pressures on coral, threatened species and their conservation, the contribution of biodiversity to carbon stocks and the national biodiversity strategy and action plan. However, although the indices used showed many pathways to explore how Brazil is performing, it is still complex to evaluate ABTs’ performance regarding coastal and marine ecosystems at a global and regional scale. 相似文献
16.
Measuring and forecasting recruitment are central to the understanding and management of fish stocks. Kainge et al. (2013) studied the effect of spawning stock size and environmental fluctuations on the recruitment levels of the Cape hake Merluccius capensis in Namibia. However, their study contains some flaws that undermine the conclusion that Cape hake recruitment is under the influence of upwelling in summer. Until those flaws are properly addressed, this conclusion, in our view, should be treated with caution. 相似文献
17.
《Marine Policy》2013
At the Rio+20 meeting in June 2012, governments of the world committed to rebuilding fish stock sizes by 2015 at least to levels that can produce the maximum sustainable yield (MSY), even if that would require the temporary closure of fisheries. This study explores the outcomes of such action for European stocks. In 2012, only 8 of 48 stocks (17%) were abundant enough to produce MSY and with a business as usual scenario, this number would not increase by 2015. In contrast, if fishing was reduced to levels consistent with rebuilding and if some fisheries were temporarily closed, 50–70% of the examined stocks would be able to reach the Rio+20 target by the end of 2015. In this scenario, after three years with reduced catches, fish supply from European stocks would reach and exceed the levels of 2011 already in 2016. The implications for fish, fishers and fish consumers are discussed. 相似文献
18.
This article discusses how the Chinese seafood industry will affect the rest of the world's fishing industries. The analysis is based on theories of economic comparative advantage, the international division of labour and the internationalization process related to trade activities. Given the increasing domestic demand for fish in China, the limited availability of domestic fish stocks and less success for farmed marine fish in China are considered some of the most important factors in restricting the growth in Chinese seafood production. The necessity of raw fish imports into China may increase pressure on global fish stocks and international fish prices, resulting in tighter supplies worldwide and higher seafood prices for the Chinese. Sustainable fish harvests and trade require stronger fishery management, in particular in the relations between seafood companies and governments along the entire international value chain supplying China. Such structural changes may allow new value-added possibilities for fish farming and the upgrading of certain fish species for human consumption that were previously utilized purely for fish feed. 相似文献
19.
《Marine Policy》2005,29(4):299-309
Norwegian spring-spawning herring (Clupea harengus) is a migratory fish stock, and the migratory pattern has changed several times. There seems to be a connection between altering climatic conditions and the size of fish, year-class strength and the migratory pattern. The changing juridical status of the herring has caused problems and conflicts between the parties involved in the fishery. Investigating whether the change is due to over fishing or to environmental causes, or a combination of both, was one of the objectives of the analysis. Furthermore, we have looked at the processes involved in finding solutions to the problem of managing straddling stocks. 相似文献
20.
In Europe, 88% of fish stocks are being fished beyond Maximum Sustainable Yield and 30% of stocks are outside of biological limits. The blue whiting fishery is also following a consistent trend of a declining, and the EU recently adopted a 93% quota decrease for this species. Despite the abundant literature related to genetic aspects of population structure of aquatic resources, few studies have specifically addressed the link between fisheries management and population genetics. Given potential differences in the behavior of different subpopulations, population genetics has great relevance in the correct interpretation of the evolution of stocks. Ignoring the congruence of spatial scales between the population structure of fish species and management units can result in reduced productivity and local reduction of populations. 相似文献