More than 2,200 dolphins and around 50 whales have been spotted at Bempton Cliffs since it became England’s first official Shorewatch location 16 months ago.
The scheme run by the Whale and Dolphin Conservation (WDC) charity trains volunteers to carry out surveys of marine life.
A team of 20 volunteers has just conducted their 1,000th observation from the clifftop at the RSPB site, which is internationally famous for the colonies of seabirds which nest on its chalk cliffs.
Susanna O’Neill, RSPB senior administrator and a Shorewatch volunteer, said reaching the milestone was “an incredible achievement and a testament to the dedication of our volunteers”.
She added: “This project has introduced thousands of visitors to the marine wildlife on East Yorkshire’s coast and to see how close the dolphins come to the cliffs has been amazing.
“By collecting long-term data on the mammals using these waters, we can better understand how environmental changes are affecting them and ensure conservation decisions are based on robust evidence.”
Volunteers use specialist marine binoculars to scan the sea for 10 minutes before they log their findings into a dedicated app.
Since the project launched in East Yorkshire, the team has logged 1,896 bottlenose dolphins, 341 harbour porpoises, 50 minke whales and a humpback whale.