Stranded dolphin rescued from six miles up Cornish river

Mr Jarvis said he believed the 7ft 3in (2.2m) dolphin had become disorientated after swimming inland to follow fish or other food sources.

Marine mammals could become disoriented by human activity, such as underwater noise or boats, he said, but “as far as we can tell in this case it was a natural phenomenon of the dolphin just getting lost”.

Mr Jarvis said there were hundreds of dolphins off the Cornish coast at this time of year and so it was not uncommon for them to swim up tidal waters, such as the River Fal, near Falmouth.

However, as the dolphin was so far inland the team felt waiting for it to find its own way out after dark when the tide had risen would be too risky, so they chose to intervene.

He said members of the public spotting dolphins or other marine mammals in distress should follow best practice for watching wildlife.

He urged people to contact BDMLR and said “there’s no need to get close”.