A report just released in relation to the mass stranding of a pod of dolphins found around the Percuil River in the Fal Estuary, Cornwall in 2008 has found no definitive reason as to why the animals beached themselves. Many of the dolphins were refloated and herded back out to sea, however 26 died.

Days before the stranding, the Navy held a large exercise in nearby waters. Several ships from the British, Dutch and German fleets were involved along with a Merlin helicopter equipped with powerful mid-frequency sonar of the type associated with previous deaths of marine mammals around the world.

Marine Connections' Liz Sandeman reports "It's very disappointing and frustrating that we will never find out the real reason for these strandings, the cause remaining unclear. Common dolphins are a pelagic species and prefer deep water, therefore it is clear that something spooked these mammals to make them react in this way. As the dolphins were found spread over a large area of coastline, we would rule out the suggested possibility that it was an error of navigation on their part. According to the post mortem results, none of the animals had obvious signs of disease."

In its report for the Institute of Zoology, the UK Cetacean Strandings Investigation Programme, said that "ultimately, a definitive cause for the mass stranding event could not be determined."

Liz Sandeman continues "Despite the fact this was one of the worst mass strandings on UK shores, the Ministry of Defence, unlike the US Navy, refuse requests from the NGO community to hold public meetings with regards to their sonar activities. It is vital the MoD monitor, and investigate in a publicly open and transparent manner, any strandings or deaths of marine mammals that may be associated with similar sonar excercises in the future. With no definite cause being found for the 2008 deaths, there is still the possiblity that these dolphins were killed as a result of naval excercises being conducted in the area at the time".

For background details on this stranding click here