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1.
  • 1. Biodiversity is probably at greater risk in freshwater systems than in other ecosystems. Although protected areas (PAs) play a vital role in the protection of biodiversity and are the mainstay of most conservation polices, the coverage of biodiversity by existing PA networks is often inadequate and few reserves are created that take into consideration freshwater biota.
  • 2. In this paper an attempt is made to address the performance of protected areas in the context of freshwater biodiversity conservation using data records for water beetles in a Mediterranean river basin.
  • 3. Although the present PAs in the study area cover a relatively high number of water beetle species, the distribution and extent of reserves is still inadequate or insufficient to protect freshwater biodiversity, especially species of conservation concern.
  • 4. Alternative area‐selection methods (hotspots and complementary) were more efficient than PAs for representing water beetles. Within these, complementarity was the most efficient approach, and was able to represent all species in a significantly lower area than the current PA network. On the other hand, the future Natura 2000 Network will result in a great increase in the total area of protected land as well as in the biodiversity represented.
  • 5. Unfortunately, the occurrence of a species within a protected area is not a guarantee of long‐term survival because the extent of PAs is often insufficient and disturbances occur outside park boundaries. Thus, whole‐catchment management and natural‐flow maintenance are indispensable strategies for freshwater biodiversity conservation.
Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

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  1. The Amazon basin has been subjected to extreme climatic events and according to climate change projections this hydrosystem could face changes in the natural dynamic of flood cycles that support the feeding and reproduction of many fish species, threatening aquatic biodiversity.
  2. Protected areas (PAs) are the main tools used to safeguard the biodiversity in the long term; however, they are fixed areas that could be subject to climate change, questioning their future efficiency in protecting biodiversity.
  3. The Amazon basin currently benefits from a relatively high level of protection as 52% of its catchment area is under the form of true PAs or indigenous lands. However, the capacity of these PAs to protect freshwater biodiversity remains unclear as they have generally been assessed with little regard to freshwater ecosystems and their hydrological connectivity. Here, the aim was to evaluate the effectiveness of PAs in representing the Amazon fish fauna under current and future climatic conditions.
  4. A macroecological approach was used to estimate the minimum size of the geographical range needed by each species to achieve long-term persistence, by a combined function of range size and body size, two ecological traits known to influence species extinction risk.
  5. In future the Amazon basin could risk losing 2% of its freshwater fish fauna owing to unsuitable climatic conditions, with a further 34% adversely affected. The present Amazon network of PAs will cover the minimum required range for species persistence for more than 60% of the freshwater fish species analysed under the future climate scenario. However, more than 25% of the future susceptible species are currently concentrated in large tributaries and in the central-lower Amazon floodplain where few PAs occur, highlighting the lack of appropriate conservation actions for these specific water bodies.
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  • 1. The Galapagos Marine Reserve provides refuge for numerous threatened marine species, including 16 mammals, birds, reptiles and fish currently recognized on the 2006 IUCN Red List of Threatened Species, plus an additional 25 endemic fish, mollusc, crustacean, echinoderm, coral and macroalgal species that comply with threatened species criteria because of declining extent of occurrence or highly‐localized ranges, and hence also qualify for inclusion on the Red List.
  • 2. Threatened marine species with restricted ranges are not randomly distributed across the archipelago but tend to co‐occur at a limited number of sites that are predominantly located in the west. Sites at which threatened species are known to persist, particularly those with a large proportion of the global population, are here identified as sites of global conservation significance — key biodiversity areas.
  • 3. The majority (27) of the 38 inshore key biodiversity areas identified are currently protected from fishing because they lie within the 17% of coastal waters that is zoned as ‘no‐take’ tourism or conservation zones. All key biodiversity areas should be protected from extractive exploitation if threatened species are to be safeguarded. This can be achieved, at the minimum, through a relatively minor amendment to the existing marine zoning scheme, whereby an additional 2% of the coastline is dedicated to conservation.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

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  1. The five global Mediterranean-climate regions are experiencing alarming rates of freshwater biodiversity loss. Although freshwater mussels are recognized as important functional components in aquatic ecosystems, and are among the most threatened faunal groups globally, there has been no synthesis of the plight of this group within these regions.
  2. Data from the International Union for Conservation of Nature (IUCN) Red List were reviewed to compare the conservation status, threats, and conservation actions needed for freshwater mussel species occurring in Mediterranean-climate regions (med-mussels) with those of other freshwater mussel species globally. The first comprehensive catalogue of med-mussel species was compiled using existing taxonomic literature.
  3. There are 41 med-mussel species, 30 of which occur in the Mediterranean basin. Many regions have just a single species, and regions where multiple species occur generally only have between one and four species per river basin. Med-mussel species are almost twice as likely to be ‘Imperilled’, are affected by 2.4 times more threats, and require 3.5 times more conservation actions than non-med mussels. In many cases, the exact threats have not been identified.
  4. In combination with low species richness, this level of imperilment means that Mediterranean-climate regions are at risk of losing the benefits that mussels provide to broader ecosystem functioning. The conservation of med-mussels can be improved by increasing our knowledge of species distributions, including the identification of cryptic species and significant management units, through population genetic work. In addition, recognizing the potential of ‘novel’ habitats and refuge areas could augment the management of this important functional group.
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  1. The European Natura 2000 (N2K) network of protected areas stands out as the main conservation strategy in the European Union to preserve biodiversity under the auspices of the Convention on Biological Diversity.
  2. The management of N2K sites is mainly focused on protecting the biological elements as Special Areas of Conservation for habitats or species listed in the European Habitats Directive, or as Special Protection Areas for birds listed in the European Birds Directive for which the site was designated. It seems urgent, therefore, to discriminate which N2K sites are really providing effective protection for aquatic biodiversity.
  3. Although the main objective of N2K is to protect species listed in the Birds and Habitats Directives, the conservation status of threatened species included in the European Red List of the IUCN must also be a concern for the European Union.
  4. Focusing on Central Spain as a case study, the aim of this work was to evaluate how far aquatic N2K (i.e. N2K sites designated for the occurrence of freshwater elements) is effective in protecting both those aquatic species in the Directives [referred to here as Species of Community Importance (SCI) and threatened species (TS)].
  5. Most of the N2K sites in the study area have been designated using aquatic elements, which means that N2K could theoretically provide appropriate mechanisms to preserve aquatic biodiversity. However, N2K provides a low percentage of overlap with some of the hotspots identified for both TS and SCI. Surprisingly, TS are in general similarly or even better represented than SCI by N2K.
  6. N2K may provide good coverage for aquatic biodiversity, mainly by acting as an umbrella for other species, but it could be improved by addressing some spatial gaps, thereby making it more relevant to current challenges such as climate change and other human impacts.
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  1. Freshwater ecosystems are essential to human well-being and most have high biodiversity. However, this biodiversity has been suffering severe declines owing to the expansion of human activities. Protected areas (PAs) are essential for biodiversity conservation and have proved to be successful in stopping species extirpation if managed properly. Unfortunately, they are usually focused on terrestrial biodiversity, leaving freshwater ecosystems aside.
  2. The main goal of this study was to determine the influence of a PA (Montesinho Natural Park (MNP), Portugal) on freshwater biodiversity. Aquatic macroinvertebrates and fishes were surveyed, and biodiversity (richness, abundance, Shannon-Wiener diversity, and Pielou's evenness) and water quality (IASPT) indices were calculated inside, at the periphery and outside the MNP.
  3. Results showed that the PA does not affect positively either water quality or the two faunal groups monitored. Macroinvertebrate communities were not influenced by the PA; however, the abundance of pearl mussel Margaritifera margaritifera was significantly higher and size was significantly lower inside the MNP. The richness and abundance of fish communities were significantly higher outside the MNP, except for trout Salmo trutta abundance which was higher inside the MNP.
  4. Given these results, the MNP does not guarantee the safeguard of overall aquatic biodiversity and habitats and we propose an extension of MNP to downstream areas in order to increase the number of species (mostly cyprinids) under legal protection. This work demonstrates that terrestrial PA planning and management should also consider aquatic biodiversity to achieve successful conservation.
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1. To consider fully the conservation management of freshwater fish, it was important to know which fish were already in the protected environment of National Nature Reserves (NNRs) — the principal sites for nature conservation in Great Britain. For this reason, 235 NNRs declared by the Nature Conservancy Council (NCC) were surveyed for freshwater fish between 1987 and 1990 by questionnaires to the wardens, by compiling data from other sources, and, where necessary, by field sampling. The presence of fresh waters (as lakes, ponds, rivers and streams) was also recorded. The survey was organized to follow the country and regional structure by which nature conservation was administered by the NCC so that the results could be considered accordingly. 2. Seventy five percent of NNRs contain fresh waters and, of these, just over 20% have no fish. Of the 51 fish species available 37 (73%) were recorded in NNRs. NCC regions with most fish species are: SW Scotland, West Midlands and East Anglia, but NW Scotland has the highest total of species occurrences in NNRs. In terms of both the numbers of species and their frequency of occurrence, NW and NE England are notably the lowest. The most common fish in NNRs are Eels, Brown Trout and Three-spined Sticklebacks. 3. The results for species and for sites (NNRs) are discussed from the viewpoint of fish conservation. The majority of fish in NNRs are those most common in Great Britain. Two of the species recorded (Powan and Smelt) are currently important for conservation, but several of those most threatened do not occur in NNRs. A number of NNRs have diverse fish communities, but only six have significant fish conservation value, of which Loch Lomond NNR is outstanding. 4. There is considerable scope through NNR management to improve fish conservation and it is suggested that the acquisition of new reserves for threatened species should be considered.  相似文献   

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Understanding biodiversity and community composition is a prerequisite to sustainable exploitation and conservation of fisheries. We assessed the spatial and seasonal patterns of fish community composition and biodiversity in seasonal no-take riverine sanctuaries in Bangladesh, which aim to conserve the anadromous hilsa shad (Tenualosa spp. and Hilsa keele). Fish samples were collected during monsoon, as well as pre- and postmonsoon, from five sites within two sanctuaries and one site in an open fishing area. Although total abundance was similar along the rivers, species richness was significantly higher at the open fishing site due to its connectivity to nearby habitats. The diversity apparently decreased in a downstream direction. Fish communities at two upstream sites were separated from other sites in multivariate space largely due to higher abundance of hilsa at downstream sites and presence of floodplain-oriented species at the two upstream sites. Short body length and high trophic level at all sites indicated that fish communities were overexploited. Our results also indicated that riverine hilsa sanctuaries in Bangladesh are rich in fish species diversity and support several threatened species designated by the International Union for Conservation of Nature (IUCN). Our study also suggested that since hilsa abundance shapes community patterns, it can therefore impact riverine ecosystem functioning in the sanctuary areas. The findings of this study can serve as an important baseline for future biodiversity assessment, conservation and impact assessment of conservation in rivers, and therefore help to establish multispecies ecosystem-based management of riverine fisheries around the world.  相似文献   

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  1. Freshwater ecosystems represent less than 0.01% of Earth's surface water but proportionately encompass the most species-rich environment on the planet, including nearly one-third of all vertebrate species. Even though inland continental waters are widely regarded as highly endangered ecosystems, their species assemblages are mostly ignored in conservation plans, largely because spatial patterns of freshwater species remain poorly understood. This is particularly severe throughout the Neotropics, most notably in the Amazon superbasin, where the sheer biotic diversity is coupled with a severe lack of biodiversity knowledge at several levels.
  2. Spatial patterns of Neotropical freshwater fishes focusing mainly on the Amazon superbasin were investigated. First, Endemic Amazonian Fish Areas (EAFAs) representing central units for the conservation of continental fishes were delimited. Interpolated maps were then analysed using alternative methodologies to delimit spatial patterns of diversity and endemicity across the Amazon superbasin. Several biogeographical analyses used a comprehensive dataset of species and geographical coordinates of Amazonian fishes.
  3. The results reveal well-defined spatial patterns of species richness and endemicity in the Amazonian fish fauna, showing that most protected areas are concentrated in a single bioregion (Amazon lowlands). Those areas are incongruent and insufficient to protect endemic and threatened species, which are mostly distributed in upland regions.
  4. Effective conservation of the Amazonian fish fauna should include EAFAs within protected areas, especially those undergoing deforestation and hydropower development pressure and containing a high concentration of threatened species.
  5. The following EAFAs should be considered as conservation priorities: Upper Araguaia, Upper Tocantins, Lower Teles Pires/Serra do Cachimbo, Chapada dos Parecis and Upper Marañon. These regions should be urgently protected to avert the loss of important trophic relationships and unique elements of the Amazonian fish fauna.
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