The International Union for Conservation of Nature's (IUCN's) Shark Specialist Group (SSG), co-chaired by Nick Dulvy, a Simon Fraser University (SFU) Canada Research Chair in Marine Biodiversity and Conservation in British Columbia, conducted the study.
It was published ineLife journal today.
Previous studies have documented local overfishing of some populations of sharks and rays. But this is the first one to survey their status through out coastal seas and oceans. It reveals that one-quarter (249) of 1,041 known shark, ray and chimaera species globally fall under three threatened categories on the IUCN Red List.
"We now know that many species of sharks and rays, not just the charismatic white sharks, face extinction across the ice-free seas of the world," says Dulvy. "There are no real sanctuaries for sharks where they are safe from overfishing."
Over two decades, the authors applied the IUCN's Red List categories and criteria to the 1,041 species at 17 workshops involving more than 300 experts. They incorporated all available information on distribution, catch, abundance, population trends, habitat use, life histories, threats and conservation measures.
Sharks and rays are at substantially higher risk of extinction than many other animals and have the lowest percentage of species considered safe. Using the IUCN Red List, the authors classified 107 species of rays (including skates) and 74 species of sharks as threatened. Just 23 percent of species were labeled as being Least Concern.
The authors identified two main hotspots for shark and ray depletion -- the Indo-Pacific (particularly the Gulf of Thailand), the Red Sea and the Mediterranean Sea.
"In the most peril are the largest species of rays and sharks, especially those living in relatively shallow water that is accessible to fisheries. The combined effects of overexploitation -- especially for the lucrative shark fin soup market -- and habit degradation are most severe for the 90 species found in freshwater.
"A whole bunch of wildly charismatic species is at risk. Rays, including the majestic manta and devil rays, are generally worse off than sharks. Unless binding commitments to protect these fish are made now, there is a real risk that our grandchildren won't see sharks and rays in the wild."
Losing these fish will be like losing whole chapters of our evolutionary history says Dulvy. "They are the only living representatives of the first lineage to have jaws, brains, placentas and the modern immune system of vertebrates."
The potential loss of the largest species is frightening for many reasons, says Dulvy. "The biggest species tend to have the greatest predatory role. The loss of top or apex predators cascades throughout marine ecosystems."
The IUCN SSG is calling on governments to safeguard sharks, rays and chimaeras through a variety of measures, including the following: prohibition on catching the most threatened species, science-based fisheries quotas, protection of key habitats and improved enforcement.
Welcome to SUV System Ltd!
SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.
We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.
SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com
SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc
we are focus on the following fields,and hope we can help you.
Chip Inductors High Precision Resistors Industrial IC HARRIS IC Metal Can Packages Transistors LINEAR IC Chip Ferrite Beads Current Sensors Resistors ON Transistors Resistor Arrays TOSHIBA Diodes MURATA IC TI IC Diodes Inc Electronic News NXP Transistors AD IC Civil IC Other Parts IR transistor Rectifier Diodes Xilinx IC Fairchild Semiconductor Transistors Atmel IC INTERSIL IC PANASONIC Resistors Renesas parts IC Voltage Regulators Transistors MOTOROLA IC Resistor Networks YAGEO Resistors Schottky Diodes Microchip IC Chip Fuses ELPIDA IC NS IC Discrete Semiconductor Transistors DIODES Transistors Zener Diodes Texas Instruments(TI) IC