Volunteers have said acting quickly is crucial to save the lives of marine animals which wash up on beaches along the Yorkshire coast.
Medics from the British Divers Marine Life Rescue (BDMLR) and representatives from the Sea Champions group were called to Bridlington South Beach yesterday afternoon after reports of a stranded harbour poprpoise.
A spokesperson for the Sea Champions said: "The adult male, was alive and found to be in moderate condition and after initial assessment a potential candidate for a refloat attempt.
"Sadly within minutes of us being on the scene the porpoise passed away.
"Takeaway messages from this incident are for members of the public to be aware to report a stranded marine mammal to the BDMLR immediately as time is critical.
"This species of cetacean is highly sensitive, both handling, dogs in the vicinity and loud noises, including voices, should be avoided as these can be detrimental to the animal and contributing factors to a decline in its condition.
"No attempts should be made to ever put a cetacean or seal back into the water without the presence of the BDMLR.
"We would like to thank the members of the public who made the call and alerted us of the location and the coastguard who later attended the scene to gather statistical information."
The body has been retrieved and will be sent to the cetacean stranding program for a necropsy.
If you find a stranded animal, call the rescue hotline on 01825 765546, Monday-to-Friday 9am to 5pm, or 07787 433412 out of office hours and on Bank Holidays.