Jan 21, 2011 14:52 GMT  ·  By
The monk seal off the coast of Mauritania is seriously endangered because of over-fishing in the area.
   The monk seal off the coast of Mauritania is seriously endangered because of over-fishing in the area.

A new study led by University of Barcelona researcher, warns that the over-exploitation of fish off the coast of Mauritania, seriously threatens two of the rarest marine mammals species in the world – the monk seal and the Atlantic humpbacked dolphin.

A team of Catalan researchers have been studying the marine trophic network in Mauritania, on the north west coast of the African continent, and they concluded that industrial and traditional fishing activities along the coast are endangering these mammals and the local marine ecosystems, AlphaGalileo reports.

Ana M. Pinela, lead author of the study and a researcher at the University of Barcelona (UB), tells SINC that “Mauritania contains some of the most heavily-exploited fisheries habitats in the whole world, with one of the world's largest fisheries stocks, which is subject to very little regulation, inspection or control.”

It is rather ironic that these waters are home to the the monk seal (Monachus monachus), which is on the verge of extinction, and to the humpbacked dolphin (Sousa teuszii), which has a very limited geographic range and is little known.

These two marine mammals are “the most coastal species of the whole area studied, and are the only ones occupying this marine ecosystem,” said the Portuguese scientist.

She adds that this area, which is 'extremely' over-exploited by both industrial and traditional fishing “should be a conservation priority for these species, which are important for biodiversity.

“If they disappear, it would be hard for others to take their place.”

Not having these two species would cause a 'serious' disturbance 'at all levels' in local coastal ecosystems, since these two 'essential' predators allow them to function properly.

The team of researchers analyzed the local marine trophic network off the coast of Mauritania, and by studying stable carbon and nitrogen isotopes, they managed to check the distribution and trophic position of 13 mammal species.

They also found out more about other species of macro seaweed, marine plants, fish, molluscs, turtles and phytoplankton, which had never been studied before.

This research shows the importance of the predators Monachus monachus and Sousa teuszii for the proper functioning of coastal ecosystems in Mauritania.

The conservation of these coastal areas should be 'a priority', according to the researchers, who add that “the Mauritanian Government and international agencies should more strongly monitor both industrial and traditional fisheries exploitation both in deep sea and coastal areas.”

Over-fishing and the over-exploitation of resources limits the availability of food for these species and damages ecosystems.

The solution to that is to implement sustainable fishing and monitoring and control of the fishing fleet, whether it's Mauritanian or international.

This study has been published in Marine Ecology Progress Series.