Mounties have set up a perimeter around the carcass of a humpback whale found beach south of Vancouver on White Rock Beach to prevent dozens of onlookers from getting too close.

The whale was discovered on the sandy tidal flats about half a kilometre east of the pier early Tuesday morning.

Vancouver Aquarium veterinarian Martin Haulena, who examined the whale, said he didn't notice any signs of life, leading him to believe the whale had been dead for several hours.

"The beached whale had lacerations on its body that are indicative of rope entanglement," he said.

"It was severely emaciated and had probably not eaten properly in a long time. The state of nutrition of the whale and scars from the gear suggest that the animal was entangled for weeks, or months."

Michael Lalonde came down to the beach when he heard the news.

"My heart is just flooding," he said. "It's really heartbreaking — humans cause so much damage to animals ... this could have come from anywhere but I don't know how they can prevent it."

Officials are expected to conduct a necropsy on the beach later Tuesday, but it remains unclear what will happen to the whale's body afterwards.

Marine biologists hope to identify the eight to 10-metre long whale by the unique pattern on its tail fluke and they will also trace the fishing gear to determine where it originated and how long the whale may have been entangled.

With files from The Canadian Press