Bluefin tuna, prized by sushi lovers, is under threat in the Mediterranean and Atlantic, the report warned [EPA]

More than 40 species of fish native to the Mediterranean are being threatened with extinction due to overfishing and illegal nets, a report has warned.

The International Union for the Conservation of Nature (IUCN), a Geneva-based environmental network, said species prized by chefs such as bluefin tuna, seabass, dusky grouper and hake, are now endangered.

Sharks and rays were some of the most threatened species because of illegal fishing nets while dolphins, whales, turtles and birds were also at risk because of overfishing, marine habitat degradation and pollution.

"The use of trawling nets is one of the main problems for conservation and sustainability of many marine species," Maria del Mar Otero, an IUCN programme officer said.

"Because it is not a selective technique, it captures not only the target fish but also a high number of other species while also destroying the sea bottom, where many fish live, reproduce and feed."

Fishing quotas 'ignored'

The report, released on Tuesday, said 43 species found in waters between southern Europe and northern Africa could disappear in the next few years unless governments acted to enforce regulations, reduce fishing quotas and create marine reserves.

It said bluefin tuna had seen around a 50 per cent drop in reproduction capacity over the past 40 years, and that many national and European Union quotas for the fish were being ignored.

Fishing in the Mediterranean is regulated by UN treaties, the European Union and separate laws among the 21 nations that border the sea.

Last November, the International Commission for the Conservation of Atlantic Tunas voted to cut the bluefin fishing quota in the eastern Atlantic and Mediterranean from 13,500 to 12,900 metric tonnes annually - about a four per cent reduction.

"The Mediterranean and eastern Atlantic population of the Atlantic bluefin tuna is of particular concern,'' Kent Carpenter, IUCN's global marine species assessment co-ordinator, said.

Japanese diners consume 80 per cent of the Atlantic and Pacific bluefins caught, as the two tuna species are especially prized by sushi lovers.

Environmental groups have been calling for a suspension of bluefin tuna fishing or major reduction.

The IUCN study, which began in 2007 and included 25 marine scientists, is the first time the group has tried to assess native marine fish species in an entire sea.

It also came as another study showed that fast-warming oceans could be pushing many fish to extinction.

The report, by Australian scientists and published in the journal Nature Climate Change, said the warming of sea-surface temperatures and the resulting increased acidity slowed fish growth rates and damaged coral reefs where they breed.

This could be especially serious for many commercial fish which do not move much, one author of the study said.

Greenpeace is also holding a conference on the plunder of African seas.

The environmental body has said that EU fishing fleets are "increasingly moving into the waters of developing countries".

Source: Agencies