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1.
This study introduces a framework for the monitoring and evaluation of spatially managed areas (SMAs), which is currently being tested by nine European case studies. The framework provides guidance on the selection, mapping, and assessment of ecosystem components and human pressures, the evaluation of management effectiveness and potential adaptations to management. Moreover, it provides a structured approach with advice on spatially explicit tools for practical tasks like the assessment of cumulative impacts of human pressures or pressure-state relationships. The case studies revealed emerging challenges, such as the lack of operational objectives within SMAs, particularly for transnational cases, data access, and stakeholder involvement. Furthermore, the emerging challenges of integrating the framework assessment using scientific information with a structured governance research analysis based mainly on qualitative information are addressed. The lessons learned will provide a better insight into the full range of methods and approaches required to support the implementation of the ecosystem approach to marine spatial management in Europe and elsewhere.  相似文献   

2.
Ecosystem-based management is one of the most important approaches that may lead to reducing the impacts of fishing on ecosystems. In this context, we have assessed the impact of Iranian coastal fishing (using landing data of 49 exploited species) on the ecosystem of the North Sea of Oman (Sistan and Baluchestan Province), during the last decade (2002–2011), with emphasis on testing the occurrence of the “fishing down? phenomenon. The Mean Trophic Level (MTL) and Fishing-in-Balance (FiB) index are two indicators that we used for analysis. The data indicated that the increased total landings in this region might be related to the exploitation of marine fishery resources especially with regard to large pelagic fish. Over the past decade, moderate decreasing trends in MTL and an increasing trend in the FiB-index were observed. In this regard, an upward trend in the spatial expansion factor and also a downward trend in the piscivory index and in Primary Production Required (PPR) in the time period could all indicate a spatial expansion toward deep waters, the catching of the large pelagic piscivorous species, such as tuna, and a sign of fishing pressures on the ecosystem. The results suggest a range of fishery exploitation patterns throughout the food web but it seems that these patterns are not a consequence of ?fishing down?. We suggest that the monitoring research be continued in this region and these indicators should be used to make fisheries management decisions and to prevent the continuance of this trend in future.  相似文献   

3.
Analyzing and evaluating the state and heterogeneity of ecosystems are required for ecosystem-based management. The abundance size spectrum is a promising approach for evaluating pelagic ecosystems. To analyze the heterogeneity of pelagic ecosystems in the northern South China Sea (NSCS) in summer, a simplified abundance size spectrum (SASS) was proposed. Picophytoplankton (0.2–2 μm), microphytoplankton (10–160 μm), mesozooplankton (160–2000 μm), and macrozooplankton (505–8,000 μm) were sampled in the NSCS in August 2007, and used to build the SASS. On the basis of the SASS parameters, spatial heterogeneity in pelagic ecosystems was detected, and the study waters were distinctly categorized into the river plume or upwelling-affected area and its adjacent coastal area, the deepwater area, area near the Luzon Strait, and the offshore shelf area. Contrasts of SASS parameters between the eastern and western pelagic ecosystems out of the Pear River estuary demonstrate the fast ecosystem response to the spreading of the Pearl River plume. These results indicate that the SASS could be a good indicator for the state of pelagic ecosystems in the NSCS. In addition, the SASS approach is easily available and labor- and time-saving, thus the SASS could be a useful tool for monitoring and evaluating the state of pelagic ecosystems and their responses to perturbations.  相似文献   

4.
The biodiversity of pelagic deep-sea ecosystems has received growing scientific interest in the last decade, especially in the framework of international marine biodiversity initiatives, such as Census of Marine Life (CoML). While a growing number of deep-sea zooplankton species has been identified and genetically characterized, little information is available on the mechanisms minimizing inter-specific competition and thus allowing closely related species to co-occur in the deep-sea pelagic realm. Focussing on the two dominant calanoid copepod families Euchaetidae and Aetideidae in Fram Strait, Arctic Ocean, the present study strives to characterize ecological niches of co-occurring species, with regard to vertical distribution, dietary composition as derived from lipid biomarkers, and trophic level on the basis of stable isotope signatures. Closely related species were usually restricted to different depth layers, resulting in a multi-layered vertical distribution pattern. Thus, vertical partitioning was an important mechanism to avoid inter-specific competition. Species occurring in the same depth strata usually belonged to different genera. They differed in fatty acid composition and trophic level, indicating different food preferences. Herbivorous Calanus represent major prey items for many omnivorous and carnivorous species throughout the water column. The seasonal and ontogenetic vertical migration of Calanus acts as a short-cut in food supply for pelagic deep-sea ecosystems in the Arctic.  相似文献   

5.
A review of indicators for an ecosystem approach to fisheries management is presented, focusing on multispecies fisheries and limited resources for assessments and implementation, as often is the case in developing countries. Emphasizing the need to link indicators to management objectives, indicators from the literature are grouped into four categories, relating to the immediate fisheries resource base (single-species and multispecies indicators) and the wider ecosystem (habitat structure and ecosystem functioning). The usefulness of these indicators is assessed along three dimensions of acceptability among stakeholders, observability, and relation to fisheries management using a traffic light approach. The top ranking indicators are highlighted as a generally good start for any particular fishery management case. It is, however, argued that, even with similar management objectives, indicators need to be specific to both ecosystems and the institutional set-up if they are to be effective for management, and that indicators may consequently differ considerably between individual management applications.  相似文献   

6.
7.
The ecosystem approach to fisheries (EAF) is a holistic paradigm that considers stocks of exploitable species, marine ecosystems and stakeholders. Management agencies must strike a balance between their capacity constraints and the requisites of management measures. Most small-scale sea cucumber fisheries of Pacific Islands have been plundered while others are being opened to commercial exploitation. Data from fishery managers and a regional workshop were used to assess the current problems, institutional constraints and solutions to the management of sea cucumber fisheries in 13 Pacific Island countries (PICs). Technical capacity was often strong for some management actions such as developing marine reserves but weak for others, such as enforcement. Using multi-disciplinary indicators, half of the fisheries were diagnosed by their managers as being overfished or depleted, despite evidence of optimistic bias. Fishery governance varied greatly among the PICs, and co-management frameworks were not typical of any cultural region. Management objectives were prioritised differently among managers but most highly ranked was to protect ecological resilience. The fishery managers proposed different sets of regulatory measures and various management actions, such as surveys to collect socio-economic and fishery-dependent data, support for local governance and strong enforcement – all widely under-practised. Pacific sea cucumber fisheries exemplify how the transition to an EAF by management institutions must involve reorganisation of their technical and human-resource capacities among management tasks. Levies on exports need to be internalised to fund improved management. Management agencies should consider a shift in resources from developing marine reserves, conducting underwater surveys and aquaculture-based restocking to strengthening enforcement capacity, stakeholder involvement and communication with fishers. In concert with these actions, short fishing seasons, shortlists of allowable species and tighter enforcement at export points may serve to turn the tide on boom-and-bust exploitation and safeguard biodiversity.  相似文献   

8.
There has been a gradual evolution in fisheries management over the past decades from a focus on sustainability of a single species or stock and resources to a focus on marine ecosystems. Among the issues to be addressed for effective implementation of ecosystem based fisheries management (EBFM) are the appropriate governance arrangements and scale for management. The purpose of this paper is to examine these issues of governance and scale as related to EBFM in tropical developing countries through an analysis of approaches being taken in the Philippines to manage fisheries on a multi-jurisdictional level. The management of fisheries and coastal resources in a number of bays and gulfs, which represent marine ecosystems, is presented. The opportunities and constraints to ecosystem based fisheries management in the Philippines are discussed and lessons for broader application of these governance structures in tropical developing country marine ecosystems are presented.  相似文献   

9.
《Ocean & Coastal Management》2003,46(3-4):235-259
Ecologists have proposed hundreds of quantitative indicators of the status of ecosystems for evaluation of and reporting on the status of marine ecosystems. The talk applies a common approach to classifying indicators, summarises the main properties of each class of indicator, and provides some illustrations.Indicators of ecosystem status have roles in both communication and decision support. For both roles, strengths and weaknesses of indicators are usually only partially known. Few have been tested systematically for sensitivity and robustness across a range of contexts… However, to determine best practices for selecting indicators for specific uses, one must have a fairly complete understanding of the information content of the various indicators. The paper explores some alternative approaches to documenting the information content of various indicators of ecosystem status.As the Precautionary Approach becomes broadly used as the basis for management decision-making, the role of indicators of ecosystem status becomes central. The PA is made operational in decision-making through use of indicators and reference points. This means that it is necessary to identify values of an ecosystem indicator associated with harm to the environment that is serious or difficult to reverse. Methods for identifying and justifying reference points for ecosystem indicators are being developed and tested, but the task is turning out to be complex. Alternative strategies for identifying reference points are reviewed.When choices must be made from a suite of candidate indicators, it is desirable make the selection on objective grounds. This requires explicit a priori criteria, on which there is not yet scientific consensus. Recent developments in this area are reviewed, and again a way forward proposed.  相似文献   

10.
Although many species in the pelagic ocean are widespread, they are not randomly distributed. These species may have associations with particular water masses or habitats, but to best understand patterns in the ocean, these habitats must be identified. Previous efforts have produced static or seasonal climatologies, which still represent smearing over habitats. The Eastern Tuna and Billfish Longline Fishery (ETBF) targets a range of high trophic level species in oceanic waters off eastern Australia. In this study, dynamic ocean habitats in the region were identified for each month based on cluster analysis of five oceanographic variables averaged at a monthly time scale and a spatial scale of 0.5° for the period 1995-2006. A total of seven persistent habitats were identified off eastern Australia with intra and interannual variation in size and location, indicating the importance of spatial and temporal variation in the dynamics of the region. The degree to which these dynamic habitats were distinguished was tested using (i) stable isotope analysis of top fish predators caught in the region and (ii) estimates of variation in estimated abundance generated from catch data from the fishery. More precise estimates (measured as lower total CV) of isotopic values from swordfish (Xiphias gladius), yellowfin tuna (Thunnus albacares) and albacore (Thunnus alalunga) were obtained for 4 of 6 isotope comparisons using the dynamic habitat groupings, which indicate that stratifying by pelagic habitat improved precision. Dynamic habitats produced more precise abundance estimates for 7 of 8 large pelagic species examined, with an average reduction in total CV of 19% compared to when abundance was estimated based on static habitat stratification. These findings could be used to guide development of effective monitoring strategies that can distinguish patterns due to environmental variation, and in the longer term, climate change.  相似文献   

11.
Coral reef resource systems are complex adaptive social-ecological systems providing vital and valuable ecosystem services for human societies such as food provision, coastal protection and recreational activities. Their sustainability is questioned in many places around the world as they experience combined effects of multiple chronic anthropogenic and natural drivers at local to global scales. From a management perspective, there is a crucial need to understand how the impact of these drivers cascade through the social-ecological system components. This study develops a transdisciplinary and participatory approach to investigating the social-ecological dynamics of a Polynesian coral reef coastal system. A preliminary conceptual model using the Driver-Pressure-State-Impact (DPSI) framework is first being built through participatory modeling workshops. Then, pressure-state relationships are assessed with the help of empirical datasets as a first step towards the validation of the DPSI model. Results shows striking social-ecological interactions with different patterns in the lagoon and in the fore reef. Local management should be: (1) less resource-focused to account more specifically to the existing typology of actors; (2) more spatially-explicit to better distinguish management objectives and actions for the lagoon and the fore reef sub-systems; and (3) more coordinated with terrestrial agencies for a coherent land-sea connection and integration that would both (i) account for existing land-sea interactions and (ii) better reflect the Polynesian cultural heritage that considers nature from ridge to reef as a whole. Such conceptual models of social-ecological systems are a useful tool to build exploratory scenarios to ultimately support planning decision-making processes.  相似文献   

12.
《Ocean & Coastal Management》2003,46(3-4):261-276
Caribbean coastal ecosystems are increasingly being threatened by natural and anthropogenic factors. The scale of these factors is at local, national, regional and global levels. Threats include the effects of fisheries and extraction, eutrophication, siltation, and pollution as well as global climate events such as El Niño and global climate change. Integrated coastal management (ICM) should clearly demonstrate the adverse effects of environmental impacts, thus justifying the need for mitigation and should evaluate the success of management efforts. ICM requires robust indicators that gauge the ‘health’ of the coast in relation to environmental, social and economic activities. Biological indicators (bioindicators) offer a signal of the biological condition in an ecosystem. Using bioindicators as an early warning of pollution or degradation in an ecosystem can help sustain critical resources. Biological indicators in the Caribbean are focused around particular ecosystems, especially coral reefs, seagrass beds and mangrove forests and include a range of biological parameters relating to particular species, groups of species and biological processes. The use of these indicators is critically reviewed and the presence or absence of a relevant framework for their use in Caribbean ICM programs is discussed.  相似文献   

13.
Marine protected areas (MPA) have been widely suggested as a tool for both fisheries management and conservation goals. These multiple objectives are hard to achieve simultaneously as sustainable development implies the balance between the specific interests of conservation and economical activities. MPA success, namely for fisheries management, entails the implementation of restrictive measures that in a short-time frame may have negative effects on local fishermen communities. It is extremely important to evaluate their performance and effectiveness aiming at a quasi-optimal management, minimizing potential impacts on the social domain. In this study, a methodology for assessing the effectiveness of MPA as a small-scale fisheries management tool was developed, based on a set of indicators grouped in four dimensions (ecological, economic, social and management and governance). The indicators were scored individually according to an original score scale of five values and a median score was calculated for every dimension. Finally, the median overall score was calculated including the scores of the four dimensions. The scores were attributed for two distinct periods: before and after MPA implementation, in order to evaluate the performance of MPA. This methodology can be applied even with few scientific data available and taking into account experts and stakeholders’ judgements. The Arrábida MPA (Portugal) was used as a case study and it was found that with the implementation of the MPA social and economical aspects were impaired (median scores decreased near one value for the period after MPA implementation), while the other two dimensions showed an improvement trend. Thus, the overall score was the same before and after MPA implementation, an intermediate scale score. Results from the application of this method can give important indications about the state of an MPA and evaluate if the initial goals are being achieved through the implemented measures. The method is of easy communication and can be a useful tool for decision making and fisheries management processes.  相似文献   

14.
Knowledge of trophic interactions between the key components of marine communities is required to understand food-web dynamics and develop ecosystem-based management approaches. In West Africa, where fisheries sustain the livelihoods of a significant part of the human population, this understanding is even more urgent, especially in the face of rapidly expanding fisheries and some stock collapses in the region. We studied the feeding ecology of the Crevalle jack Caranx hippos, West African Spanish mackerel Scomberomorus tritor and Guinean barracuda Sphyraena afra in the Bijagós Archipelago, Guinea-Bissau. These are the most abundant pelagic predatory teleost fishes in the area, but little is known about their ecology despite being species with commercial and recreational value, and they likely also play an important role in various African coastal ecosystems. Our findings show a high degree of dietary overlap among these three predator species, despite some degree of segregation by prey size and type. All three predators depend on Sardinella maderensis as the most important prey, which together with other members of the Clupeidae represented 47–96% of the ingested prey items. There was little difference in the diets of the predators between the dry and rainy seasons. These novel findings suggest a ‘wasp-waist’-structured ecosystem in the Bijagós Archipelago in which S. maderensis is the central small-sized pelagic fish species, and stress the need for an ecosystem-based approach to fisheries management in the region, with precautionary measures taken to avoid the overexploitation of clupeids.  相似文献   

15.
《Ocean & Coastal Management》2003,46(3-4):277-297
Different signals of distress from the North Sea ecosystems started a discussion on the protection of the ecosystem at the third North Sea Ministers Conference in 1990. This was followed by a number of workshops on ecological indicators under the auspices of the North Sea Task Force and the Oslo and Paris Commissions (OSPAR). In 1997 the member countries around the North Sea agreed to develop and apply an ecosystem's approach in the management programs for both the North Sea fisheries and the marine environment. Following this agreement the identification of the ecological qualities objectives for the North Sea ecosystem started. Further work in this direction has lead to the setting up of various national projects geared towards creating a better understanding of the North Sea ecosystem.In the Netherlands, two departments (Water management and Nature and fisheries management) from the Ministry of Transport, Public works and Water Management (V&W) and the Ministry of Agriculture, Nature and Fisheries Management (LNV) agreed to integrate their policies for the management of the Netherlands section of the North Sea. The results from these projects (started in 1996) should enable the policy makers and managers to formulate policies that could lead to the creation of a balance between the effects of human activities and the preservation of the natural qualities of the North Sea ecosystem.One of the projects is strictly designed to develop ecological indicators for the Dutch part of the North Sea. These indicators are based on various monitoring data and related in one way or another with human activities. In this way it is possible to evaluate the effects of human impacts on the ecosystem. Long-term changes in the ecological performance of the ecosystem can be elucidated by the use of the ecological indicators. Thereby making it possible for the policy makers and the managers of the NCP to evaluate the effects of their policies and management recommendations on the quality of the ecosystem.This paper describes the process and the steps taken by the authorities in the countries around the North Sea to develop a set of ecological indicators for the management of the North Sea ecosystem. Focus will be made on the efforts made in the Netherlands to develop indicators that did provide the basis for the development of Water and Nature conservation policies and new management strategies for maintaining the sustainable use of the Dutch section of the North Sea.  相似文献   

16.
Conventional sectoral management and piecemeal governance are considered less and less appropriate in pursuit of sustainable development. Ecosystem based marine spatial management (EB-MSM) is an approach that recognizes the full array of interactions within an ecosystem, including human uses, rather than considering single issues, species, or ecosystem services in isolation. Marine spatial planning and ocean zoning are emerging concepts that can support EB-MSM. EB-MSM is driven by high-level goals that managers aim to achieve through the implementation of measures. High-level goals and objectives need to be translated into more operational objectives before specific targets, limits and measures can be elaborated.Monitoring, evaluation and adaptation are necessary to ensure that marine management measures are both effective and efficient. Solid monitoring frameworks are the foundation of adaptive management, as they provide the necessary information to evaluate performance and the effectiveness of management actions. Marine protected areas (MPAs) - possibly set up in networks - constitute a key component in EB-MSM policies and practises and have been applied as a cornerstone in conservation of marine biodiversity, management of fish populations, development of coastal tourism, etc. Moreover, MPA experiences have provided methods and concepts (such as zoning) to a wider EB-MSM context. The assignment of values to biophysical features of the marine environment allows the direct assessment of related management choices and may assist EB-MSM.A range of monetary valuation techniques have been proposed to reduce attributes of goods and services to a single metric. However, in the marine environment such an approach is often over simplistic, and thus less reductive techniques may be necessary. Rather than producing a single metric, the results of non-monetary assessments guide policy allowing weight to be given as necessary to potential areas of conflict and consensus.Strategies to take into account climate change effects and geohazard risks in EB-MSM have been applied or proposed worldwide. EB-MSM regimes must be alert to such risks and flexible to account for changes.  相似文献   

17.
《Coastal Engineering》2005,52(10-11):1073-1087
Coastal areas play a crucial role in the economical, social and political development of most countries; they support diverse and productive coastal ecosystems that provide valuable goods and services. Globally flooding and coastal erosion represent serious threats along many coastlines, and will become more serious as a consequence of human-induced changes and accelerated sea-level rise. Over the past century, hard coastal defence structures have become ubiquitous features of coastal landscapes as a response to these threats. The proliferation of defence works can affect over half of the shoreline in some regions and results in dramatic changes to the coastal environment. Surprisingly little attention has been paid to the ecological consequences of coastal defence. Results from the DELOS (Environmental Design of Low Crested Coastal Defence Structures, EVK3-CT-2000-00041) project indicate that the construction of coastal defence structures will affect coastal ecosystems. The consequences can be seen on a local scale, as disruption of surrounding soft-bottom environments and introduction of new artificial hard-bottom habitats, with consequent changes to the native assemblages of the areas. Proliferation of coastal defence structures can also have critical impacts on regional species diversity, removing isolating barriers, favouring the spread of non-native species and increasing habitat heterogeneity. Knowledge of the environmental context in which coastal defence structures are placed is fundamental to an effective management of these structures as, while there are some general consequences of such construction, many effects are site specific. Advice is provided to meet specific management goals, which include mitigating specific impacts on the environment, such as minimising changes to surrounding sediments, spread of exotic species or growth of nuisance species, and/or enhancing specific natural resources, for example enhancing fish recruitment or promoting diverse assemblages for eco-tourism. The DELOS project points out that the downstream effects of defence structures on coastal processes and regional-scale impacts on biodiversity necessitate planning and management at a regional (large coastline) scale. To effectively understand and manage coastal defences, environmental management goals must be clearly stated and incorporated into the planning, construction, and monitoring stages.  相似文献   

18.
Abundance and biomass of the most important fish species inhabited the Barents and Norwegian Sea ecosystems have shown considerable fluctuations over the last decades. These fluctuations connected with fishing pressure resulted in the trophic structure alterations of the ecosystems. Resilience and other theoretical concepts (top-down, wasp-waste and bottom-up control, trophic cascades) were viewed to examine different response of the Norwegian and Barents Sea ecosystems on disturbing forces. Differences in the trophic structure and functioning of Barents and Norwegian Sea ecosystems as well as factors that might influence the resilience of the marine ecosystems, including climatic fluctuation, variations in prey and predator species abundance, alterations in their regular migrations, and fishing exploitation were also considered. The trophic chain lengths in the deep Norwegian Sea are shorter, and energy transfer occurs mainly through the pelagic fish/invertebrates communities. The shallow Barents Sea is characterized by longer trophic chains, providing more energy flow into their benthic assemblages. The trophic mechanisms observed in the Norwegian Sea food webs dominated by the top-down control, i.e. the past removal of Norwegian Spring spawning followed by zooplankton development and intrusion of blue whiting and mackerel into the area. The wasp-waist response is shown to be the most pronounced effect in the Barents Sea, related to the position of capelin in the ecosystem; large fluctuations in the capelin abundance have been strengthened by intensive fishery. Closer links between ecological and fisheries sciences are needed to elaborate and test various food webs and multispecies models available.  相似文献   

19.
Escalating pressures caused by the combined effects of population growth, demographic shifts, economic development and global climate change pose unprecedented threats to sandy beach ecosystems worldwide. Conservation of beaches as functional ecosystems and protection of their unique biodiversity requires management interventions that not only mitigate threats to physical properties of sandy shores, but also include ecological dimensions. Yet, beach management remains overwhelmingly focused on engineering interventions. Here we summarise the key outcomes of several workshops, held during the 2006 Sandy Beach Ecology Symposium in Vigo, Spain, that addressed issues of climate change, beach management and sampling methodology. Because efficient communication between managers and ecologists is critical, we summarise the salient features of sandy beaches as functional ecosystems in 50 'key statements'; these provide a succinct synopsis of the main structural and functional characteristics of these highly dynamic systems. Key outcomes of the workshops include a set of recommendations on designs and methods for sampling the benthic infaunal communities of beaches, the identification of the main ecological effects caused by direct and indirect human interventions, the predicted consequence of climate change for beach ecosystems, and priority areas for future research.  相似文献   

20.
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