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Shark fins tracked by DNA

By Lucy Brake - 29 Apr 2011 9:20:0 GMT
Shark fins tracked by DNA

The finding that sharks have DNA 'zip codes' means that the fight against the shark fin trade is strengthened as scientists can work out what region sharks where born in.

A team of international researchers, led by the Institute for Ocean Conservation Science in New York, has successfully used DNA to confirm that there are separate groups of both dusky sharks and cooper sharks living in distinct coastal areas. Both of these species of sharks are highly prized for their shark fins and they are facing serious threats from the shark finning trade.

Whilst sharks tend to have a wide habitat in which they live, they are connected to the coastal regions where they always go to reproduce. Dr. Demian Chapman, leader of the research team and assistant director of science of the Institute for Ocean Conservation Science, said ''By analysing part of the genome that is inherited solely through the mother, we were able to detect differences between sharks living along different continents, in effect their DNA zip codes''.

It would seem this might just turn out to save their lives as it means each population is likely to have distinct genetic patterns. Chapman explains that this research shows that adult females faithfully give birth along the continental region where they were born and ''if fished too much, the population will collapse, and it is extremely unlikely that it will be replenished from immigration of sharks from another region''.

The International Union for Conservation of Nature classifies the dusky shark in the Western Atlantic as Endangered and that their population is below one fifth of the levels it was at only 20 years ago. Luckily enough this latest research has shown that the differences in the genetic makeup of the shark populations are big enough to enable scientists to actually track the origin of the fins.

The outcome of this research is that regional populations of sharks can be prioritised for management in the fight against the shark finners. This means that better monitoring in local areas as well as improved regional management practices can be put in place to protect these predators at the top of the food chain.