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Bio­di­ver­sity


A Col­lec­tion of News by Moos


201124Aug15:06

The Mediter­ranean Sea is get­ting empty; fish deple­tion ongoing

Infor­ma­tion
pub­lished 24 August 2011 | mod­i­fied 19 April 2011
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In the com­ing years more than fourty species of fish could dis­ap­pear from the Mediter­ranean Sea, accord­ing the IUCN in a recently pub­lished report. These species are clas­si­fied accord­ing the IUCN’s Red List method­ol­ogy as Crit­i­cally Endan­gered, Endan­gered or Vul­ner­a­ble. The main threats are over­fish­ing, pol­lu­tion, habi­tat degra­da­tion and human disturbance.

The IUCN report reviews the con­ser­va­tion sta­tus of all native marine fishes occur­ring in the Mediter­ranean Sea, based on the assess­ments for 513 species and 6 sub­species. The assess­ment was car­ried out dur­ing the course of two expert work­shops in 2007 and 2008, and through cor­re­spon­dence with rel­e­vant experts. There was not enough data avail­able for almost one-​third (151 species) of the Mediter­ranean marine fishes to esti­mate their risk of extinc­tion. Only if more data becomes avail­able, the true pro­por­tion of threat­ened species can be cal­cu­lated, and might be much higher.

It is note­wor­thy to men­tion that for those species that are endemic to the Mediter­ranean Sea, the regional assess­ments should be con­sid­ered to be global assess­ments, as the species rep­re­sent the entire global pop­u­la­tion of the species.

Sharks and rays are by far the most threat­ened class of marine fishes in the Mediter­ranean Sea, with 31 species (40%) in threat­ened cat­e­gories. But also com­mer­cial species like Bluefin Tuna, Sea Bass and Hake are con­sid­ered threat­ened or near threat­ened with extinc­tion mainly due to over­fish­ing. The Mediter­ranean and East­ern Atlantic pop­u­la­tion of the Atlantic Bluefin Tuna is of par­tic­u­lar con­cern. Over­fish­ing has has caused an esti­mated 50% decline in this species’ repro­duc­tion poten­tial over the past 40 years. Con­ser­va­tion effort for this species has been under­minded by lack of com­pli­ance with fish­ing quo­tas and wide­spread under­re­port­ing of the catch.

The use of fish­ing tech­niques and gear, like fish­ing lines, trawl­ing nets, and ille­gal drift­nets has led to unnec­es­sary by-​catch of many ani­mals with no com­mer­cial value. These sharks, rays, dol­phins, whales, tur­tles and even spe­cific birds are threat­ened with extinc­tion too.

The study empha­sises the need to review fish­ing quo­tas, rein­force fish­ing reg­u­la­tions, cre­ate new marine pro­tected areas, reduce pol­lu­tion. Next to the need for addi­tional fund­ing of research into the sta­tus of endemic Mediter­ranean marine fish species, and gen­er­ate data on other data defi­cient species. (Sources: NRC, 19.04.2011; IUCN, 19.04.2011)

UN Biodiversity decade

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
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