Greenpeace has found seven dead dolphins in under three days while investigating fishing fleets in the English Channel. All the dolphins found had drowned and had suffered damaged beaks and torn flippers - injuries likely to have been caused trying to escape from huge fishing nets commonly used to 'pair trawl' in the area.
The first five dead dolphins were spotted Friday morning around 20 miles off the coast near Plymouth. Two pairs of French trawlers were in the vicinity. Four of the dead animals were recovered, still bleeding, using Greenpeace's inflatable boats. The fifth sank before it could be retrieved. All were apparently healthy adult male common dolphins (Delphinus delphis) and body temperature readings suggested they had only recently died. A large section of fishing net was also found in the same area. Two further dead adult male dolphins were discovered on Sunday, one around midday and the other at 2.30pm. Again, a section of fishing net was found in water nearby.
Sarah Duthie, Greenpeace Oceans Campaigner onboard the Esperanza, said: "It's hard to spot dolphins dead or alive in grey choppy seas in winter. Dead dolphins are only visible just 50 metres from our ship. The sad fact is that if we've found seven dead dolphins in just a few days then there could be hundreds more out there we never see.
"We need urgent government measure to find out which fishing vessels are killing these dolphins and then action to stop it happening. If we don't then one day we may not see dolphins and porpoises alive in the English Channel."
Mark Simmonds, WDCS's Director of Science said: "All the indications are that the current situation is unsustainable. Very large numbers of animals have been killed in this region every winter for many years. In addition, the wounds on their bodies show that their deaths are often long and painful. It is high time that this ended."
All the dolphins found were photographed and measured, injuries and marks catalogued and body temperatures taken. The dead dolphins brought onboard Greenpeace' ship the Esperanza will be returned to land and handed over to the Zoological Society for post-mortem. Other dead dolphins will be documented and then carefully tagged to see if they wash ashore.
While many organisations and volunteers work to collate evidence from dead dolphins and porpoises washed ashore and there is a national strandings programme co-ordinated by the Natural History Museum, little is known about dead dolphins in the sea and they are rarely retrieved so soon after death.
Around 1,000 dead dolphins and porpoises wash up on the beaches of Britain and France every year. Using data on currents and weather and limited tagging studies, scientists estimate that 10% of dolphins and porpoises killed in fishing nets wash up on the shore, meaning around 9,000 animals are never recovered. Any data recorded from the tagged dead dolphins will help further assess the likelihood of dolphin carcasses reaching the shore and the estimated death toll.
The expedition to investigate dolphin deaths, which started on the 21 January on the Esperanza, also includes scientific research led by the Whale and Dolphin Conservation Society (WDCS) into the distribution of whales, dolphins and porpoises around the UK and French coasts. Very little is known about the abundance and distribution of these animals in these areas in the winter.
A recent report by WDCS for Greenpeace warned that some dolphins and porpoise populations could be pushed towards extinction by destructive fishing practices. The report shows that huge nets, often big enough to hold 12 jumbo jets and pulled by two trawlers at once, are killing thousands of dolphins every year. For species such as the common dolphin, this could amount to as much as 5% of the population a year. The loss of even 1% is considered by scientists to be a real cause for concern.
Pelagic (or mid-water) trawling in pairs or singly for sea bass, mackerel, horse mackerel, hake and, in the summer, albacore tuna is believed to be responsible for dolphin deaths. The UK, France, Holland, Spain, Ireland and Denmark all have pelagic vessels fishing in the Channel, Irish Sea and Bay of Biscay.
