The scientific journal PLOS ONE has published the results of four years of research into the UK’s largest ever mass stranding event of marine mammals [MSE] – on 9th June 2008.
This took place in Falmouth Bay in Cornwall, with 26 dolphins dying and around the same number managed back to sea.
The researchers were able to exclude or count as highly unlikely, a range of possible causes of the event – like by-catch, infectious diseases [post mortems found no traces], boat strike, gas/fat embolism, predator attack…
They were able to rule out all but one of these – the impact of sonar devices used by the Royal Navy.
This most likely cause is strengthened by the fact that the Navy was on international strategic exercise in the area at the time and was using a range of sonar devices used to detect the presence of submarines invisible to other means of detection.
The scientists have identified two phases of unusual behaviour in the dolphins, indicating that there may have been two separate triggers driving the event that ended so disastrously.
Two phases in the relevant activity of the naval exercise appear to have coincided with these abnormal behaviours by the dolphins.
With other possible causes rules out by scientific testing, the impact of coincidence rather beggars belief.
The scientists, say, with respectable caution, ‘The international naval activities are the only established cause which cannot be eliminated and is ultimately considered the most probable – but not definitive – cause.’
The Navy says, offering no supporting evidence: ‘We do not agree with this report. Even its own investigation has found no evidence now show naval activity was responsible.’
But it has found no evidence to show it was not responsible, while evidence was found to show every other possible cause was not responsible.
The research report concludes: ‘The international naval activities that took place in very close temporal and spatial proximity to this MSE are the only established cause of cetacean MSEs which cannot be eliminated and is ultimately considered the most probable (but not definitive) cause.’
Here is the research report in question – What Caused the UK’s Largest Common Dolphin (Delphinus delphis) Mass Stranding Event? – as published by PLOS ONE.
The research was led by Dr Paul Jepson of the Institute of Zoology with Robert Deaville, Karina Acevedo-Whitehouse, James Barnett, Andrew Brownlow, Robert L. Brownell Jr., Frances C. Clare, Nick Davison, Robin J. Law, Jan Loveridge, Shaheed K. Macgregor, Steven Morris, Sinéad Murphy, Rod Penrose, Matthew W. Perkins, Eunice Pinn, Henrike Seibel, Ursula Siebert, Eva Sierra, Victor Simpson, Mark L. Tasker, Nick Tregenza, Andrew A. Cunningham and Antonio Fernández.