For hours on Saturday (April 20) hundreds of locals crowded on Teddington Bridge to watch a stranded dolphin and her baby calf swim and surface across the fast flowing river.

One local Isobel Clark said: "It was amazing.!

"The dolphin swam back and forward for hours and the calf stayed close to her all the time.

"They surfaced briefly every couple of minutes.

"They seemed so lost and weren't sure where to go. It was all rather sad."

The news comes after a porpoise was spotted in the Thames near Richmond in March.

A grey seal was seen in Teddington Lock in January.