After swimming around super close to shore in Somerset, the dolphin that caused a stir on Monday [Aug 12] has returned to the deeper waters and has not been spotted close to shore since.

Dr Ian Walker of the Bermuda, Aquarium, Museum & Zoo [BAMZ] said they received notice about the dolphin, with reports coming in indicating that it looked like it was in trouble.

Dolphin Quest had responded, and Dr Walker and the team from BAMZ made their way to the west end by land and sea. Dr Walker said Dolphin Quest advised people not to swim with the dolphin for both the safety of people and the dolphin itself.

Dr Walker said the dolphin was coming in really close to the beach — at times only a few feet off — and was acting in an unusual manner, and the concern was that the dolphin would get stranded, as in stuck on the beach.

The BAMZ team set up field hospital, with a local water trucker bringing in 4 loads of water to fill up an inflatable pool that would be used to hold the dolphin if need be.

However at about 4.30pm, the dolphin started swimming out to shore. The Marine Police followed at a distance and lost sight of him in the Kings Point area. Dr Walker said as of 8am this morning, no one has seen the dolphin close to shore, but they have left the pool up as a precautionary measure.

Dr Walker also said they were aware of the unusual mortality event on the East Coast of the United States, and said there was concern it was possibly associated.

More than 120 dead dolphins have been discovered since June from New Jersey to Virginia, the U.S. National Oceanic and Atmospheric Administration’s Fisheries Service said.

This is seven times higher than usual, and U.S. Federal scientists have declared it an “unusual mortality event” and are investigating the cause, Reuters reports.