A dolphin is spotted near Luon Cave in Ha Long Bay, Quang Ninh province, on March 29 morning. (Photo: VNA)

Specifically, images and clips of a pod of dolphins swimming at the location of Luon cave, Ha Long Bay, Quang Ninh province, appeared on social networks on March 29 morning.

A man from the Essen Grand travel agency said that at about 7 am on March 29, he saw dolphins swimming on the surface of the water for about 10 minutes.

Earlier, on March 27, two white whales were also spotted on water surrounding Van Don area.

Since 2023, many schools of dolphins, whales and seagulls have been spotted around Co To island. Most recently, on January 20, a school of about 30 dolphins were spotted in the area.

The presence of dolphins in the waters of Van Don, Co To, Mong Cai and Ha Long Bay is a positive signal for environmental protection efforts to attract marine life to Quang Ninh./.VNA