Aquatic Conservation: Marine and Freshwater Ecosystems
نویسندگان
چکیده
1. Fishing spans all oceans and the impact on ocean predators such as sharks and rays is largely unknown. A lack of data and complicated jurisdictional issues present particular challenges for assessing and conserving high seas biodiversity. It is clear, however, that pelagic sharks and rays of the open ocean are subject to high and often unrestricted levels of mortality from bycatch and targeted fisheries for their meat and valuable fins. 2. These species exhibit a wide range of life-history characteristics, but many have relatively low productivity and consequently relatively high intrinsic vulnerability to over-exploitation. The IUCN}World Conservation Union Red List criteria were used to assess the global status of 21 oceanic pelagic shark and ray species. 3. Three-quarters (16) of these species are classified as Threatened or Near Threatened. Eleven species are globally threatened with higher risk of extinction: the giant devilray is Endangered, ten sharks are Vulnerable and a further five species are Near Threatened. Threat status depends on the interaction between the demographic resilience of the species and intensity of fisheries exploitation. 4. Most threatened species, like the shortfin mako shark, have low population increase rates and suffer high fishing mortality throughout their range. Species with a lower risk of extinction have either fast, resilient life histories (e.g. pelagic stingray) or are species with slow, less resilient life histories but subject to fisheries management (e.g. salmon shark). 5. Recommendations, including implementing and enforcing finning bans and catch limits, are made to guide effective conservation and management of these sharks and rays. Copyright # 2008 John Wiley & Sons, Ltd. Received 26 November 2007; Revised 17 January 2008; Accepted 12 February 2008
منابع مشابه
Written Testimony Of
Good morning, Madam Chairwoman, and members of the Subcommittee. My name is Tracy Collier, I am the Director of the Environmental Conservation Division, in the Northwest Fisheries Science Center of the National Marine Fisheries Service (NMFS), within the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce. Research conducted within my Division focuses on the effe...
متن کاملDistribution, structure and function of Nordic eelgrass (Zostera marina) ecosystems: implications for coastal management and conservation
This paper focuses on the marine foundation eelgrass species, Zostera marina, along a gradient from the northern Baltic Sea to the north-east Atlantic. This vast region supports a minimum of 1480 km2 eelgrass (maximum >2100 km2), which corresponds to more than four times the previously quantified area of eelgrass in Western Europe.Eelgrass meadows in the low salinity Baltic Sea support the high...
متن کاملEffects of acidification on olfactory-mediated behaviour in freshwater and marine ecosystems: a synthesis.
For many aquatic organisms, olfactory-mediated behaviour is essential to the maintenance of numerous fitness-enhancing activities, including foraging, reproduction and predator avoidance. Studies in both freshwater and marine ecosystems have demonstrated significant impacts of anthropogenic acidification on olfactory abilities of fish and macroinvertebrates, leading to impaired behavioural resp...
متن کاملK-Pg extinction patterns in marine and freshwater environments: The impact winter model
[1] The Chicxulub asteroid impact produced massive extinction in terrestrial environments most likely through an intense heat pulse and subsequent widespread fires. Aquatic environments were shielded from this heat and fire but nevertheless showed massive extinction in marine environments and, for reasons unexplained, far less extinction in freshwater environments. Extinction in marine environm...
متن کاملEcological Monitoring, Assessment, and Management in Freshwater Systems
Ecological monitoring and assessment is fundamental for effective management of ecosystems. As an introduction to this Special Issue, this editorial provides an overview of “Ecological Monitoring, Assessment, and Management in Freshwater Systems”. This issue contains a review article on monitoring surface waters, and research papers on data management, biological assessment of aquatic ecosystem...
متن کاملConserving Ocean Biodiversity: Trends and Challenges
The ocean’s biological diversity—its genetic resources, species, and ecosystems—provides immense benefits to the United States and to all of human society. Knowledge about these resources is still rudimentary; however, trends in the best studied species and ecosystems— commercially exploited fishes, protected marine mammals and turtles, and certain coastal ecosystems, such as coral reefs— indic...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008