14 research outputs found
The Living Planet Index (LPI) for migratory freshwater fish:Technical Report
Migratory freshwater fish (i.e. fish that use freshwater systems, either partly or exclusively) occur around the world and travel between critical habitats to complete their life cycle. They are disproportionately threatened compared to other fish groups but global trends in abun-dance, regional differences and drivers of patterns have not yet been comprehensively described. Using abundance information from the Living Planet Database, we found widespread declines between 1970 and 2016 in tropical and temperate areas and across all regions, all migration categories and all populations. Globally, migratory freshwater fish have declined by an average of 76%. Average declines have been more pronounced in Europe (-93%) and Latin America & Caribbean (-84%), and least in North America (-28%). The percentage of species represented was highest in the two temperate regions of Europe and North America (almost 50%). For the continents of Africa, Asia, Oceania, and South America, data was highly deficient, and we advise against making conclusions on the status of migratory freshwater SUMMARYfish in these areas. Potamodromous fish, have declined more than fish migrating between fresh and salt water on average (-83% vs -73%). Populations that are known to be affected by threats anywhere along their migration routes show an average decline of 94% while those not threatened at the population level have increased on av-erage. Habitat degradation, alteration, and loss accounted for around a half of threats to migratory fish, while over-exploitation accounted for around one-third. Protected, regulated and exploited populations decreased less than unmanaged ones, with the most often recorded actions being related to fisheries regulations, including fishing restrictions, no-take zones, fisheries closures, bycatch reductions and stocking (these were most com-mon in North America and Europe). Recorded reasons for observed increases tended to be mostly unknown or un-described, especially in tropical regions. This information is needed to assemble a more complete picture to assess how declines in migratory freshwater fishes could be reduced or reversed. Our findings confirm that migratory freshwater fish may be more threatened throughout their range than previously documented
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Global Swimways for the conservation of migratory freshwater fishes
Abstract: Anthropogenic activities have severely degraded the ecological integrity of global freshwater systems. Migratory freshwater fishes are especially threatened by the cumulative effects of multiple stressors and fragmentation, particularly those that impede access to critical habitats. To stimulate the conservation and protection of these species, we propose a “Global Swimways” program to identify rivers that support the migration routes of biologically and/or socioeconomically important freshwater fishes. We test the utility of the International Union for Conservation of Nature Red List data to support the identification of Global Swimways and present case study regions containing rivers with either high species richness (west‐central Africa and Southeast Asia), high numbers of threatened species (Eastern Europe and Central Asia), or multiple endemic species (the Rift Valley lakes in East Africa). We hope the Global Swimways program will provide metrics that can be used to identify rivers requiring increased protection or restoration, track trends, and stimulate the greater inclusion of migratory freshwater fishes in global policy mechanisms. Front Ecol Environ 2022
Improving self-management in insulin-treated adults participating in diabetes education. The role of overprotection by the partner
World Fish Migration Day Connects Fish, Rivers, and People – From a One‐Day Event to a Broader Social Movement
Rehabilitación cardíaca en pacientes con infarto de miocardio. Resultados tras 10 años de seguimiento
More than one million barriers fragment Europe’s rivers
Rivers support some of Earth’s richest biodiversity1 and provide essential ecosystem services to society2, but they are often fragmented by barriers to free flow3. In Europe, attempts to quantify river connectivity have been hampered by the absence of a harmonized barrier database. Here we show that there are at least 1.2 million instream barriers in 36 European countries (with a mean density of 0.74 barriers per kilometre), 68 per cent of which are structures less than two metres in height that are often overlooked. Standardized walkover surveys along 2,715 kilometres of stream length for 147 rivers indicate that existing records underestimate barrier numbers by about 61 per cent. The highest barrier densities occur in the heavily modified rivers of central Europe and the lowest barrier densities occur in the most remote, sparsely populated alpine areas. Across Europe, the main predictors of barrier density are agricultural pressure, density of river-road crossings, extent of surface water and elevation. Relatively unfragmented rivers are still found in the Balkans, the Baltic states and parts of Scandinavia and southern Europe, but these require urgent protection from proposed dam developments. Our findings could inform the implementation of the EU Biodiversity Strategy, which aims to reconnect 25,000 kilometres of Europe’s rivers by 2030, but achieving this will require a paradigm shift in river restoration that recognizes the widespread impacts caused by small barriers