Advertisement

Britain’s bottlenose dolphins threatened with extinction

Pod of bottle nose dolphins in the English Channel
Almost 7,500 sightings were analysed in the first study of the pod - APEX

A pod of British bottlenose dolphins “could go extinct” with fewer than 50 now living in the Channel, a study has found.

The dolphins, which are one of four pods in the UK, have been seen by locals for years but recent concern for their welfare led to the first study to determine the health and size of the group.

Almost 7,500 sightings taken by members of the public since the year 2000 were analysed by scientists at Plymouth University who concluded the current size is just 48 individuals.

It is the first study to assess the population of bottlenose dolphins and has raised concern.

Dr Simon Ingram, study author, said that if the population continues to struggle then the animals could go locally extinct, which would see Britain lose one of its few resident bottlenose dolphins.

This, he added, would be “a local tragedy for the dolphins and for us”.

Human stressors

The English Channel is one of the busiest shipping routes in the world and is also suffering from high chemical and noise pollution which are harmful to marine mammals.

He said: “The south coast of England is a highly impacted coastline with multiple human stressors including fisheries, shipping, noise, recreational boating, pollution.”

A similar population off the coast of Northern France, in the Gulf of Normandy, is in much better shape, data shows, with more than 600 individuals in one pod.

The UK dolphins were seen to have an average range of 530 kilometres (329.3 miles), but some travelled more than 700 km (435 miles), data show.

“The fact that the dolphins are ranging very widely but appear constricted to the coast puts them at a high and changing risk (depending on where they are at any one time),” Dr Ingram said.

The study, published in the journal Animal Conservation noted that adult survival rates were relatively stable over the last decade, but the small population size puts the animals in a precarious situation.

Shauna Corr, a masters student who was involved in the research, said: “Conservation measures to protect these animals have previously been hindered by a lack of knowledge of population size, distribution, and ranging behaviour.

“Thanks to a citizen science network stretching right along the English Channel and beyond, we can now fill these knowledge gaps.

“By highlighting the most damaging human activities, and regions of conservation significance, our results will be useful for developing management policies for threat mitigation and population conservation, to protect this vulnerable group.”

According to the UK’s Marine and Monitoring Assessment Strategy, there are 700 coastal bottlenose dolphins in the UK in four separate pods in the East and West coasts Scotland, South West England, and Wales.