Saturday, January 28, 2023

Sperm whale strands on Kaua'i's Lydgate Beach at Wailua


An adult sperm whale washed ashore early today (Saturday, January 28, 2023) at Lydgate Park in Wailua, on Kaua’i.

The county issued a press release urging people to stay away from the popular beach park while government agencies respond to the incident.

The marine mammal appeared by initial estimates to be more than 50 feet in length, and could weigh 30-45 tons.

The whale was reported visible on the reef off the beach park Friday afternoon, apparently already dead. By morning it was washing in the shorebreak. Government officials were working to determine how to deal with the animal.

Sometimes dead marine mammals are brought ashore for burial. Sometimes they are towed out to sea. And occasionally, particularly when they are in remote locations, they are left to decompose in place, where they become a major food resource for crabs and other coastal marine life.

However, Kaua’i County’s Lydgate Beach Park is hardly a remote location. It gets hundreds of visitors daily for its white sand beach, protected swimming area, pavilions, playground, tennis courts and more. The whale carcass was roughly in the middle of the beach fronting the park, about 1,500 feet south of the mouth of Wailua River.

No cause of death has been determined, but National Oceanic and Atmospheric Administration personnel, along with state Department of Land and Natural Resources personnel, will conduct a necropsy to gather evidence.

In a 2017 stranding of five pilot whales at Kalapaki Beach, about six miles south of Lydgate, the animals were removed to a remote island location, where necropsies were conducted before burial of the whales.

Sperm whales are found regularly in the deep waters off the Hawaiian Islands and the rest of the Pacific, and they were a key target of the whaling fleets that operated around the Islands during the early 1800s. There have been sperm whale strandings on several Hawaiian Islands.

In December 2021, an adult sperm whale washed ashore at Pila’a, Kaua’i, about a dozen miles north of Wailua.

Whale strandings and deaths have been linked to disease, parasites, impact injuries from watercraft and other causes, but the cause of many strandings is never determined.

Newsweek earlier this month reported an unusual increase in marine mammal strandings recently, including two sperm whales and seven humpbacks in the North Atlantic since December. 

NOAA Fisheries reports that on average, there are 20 strandings of whales or dolphins in the Hawaiian Islands in any given year. 

Just this week, researchers at the University of Hawai’i and NOAA reported on a newly discovered virus that was found in the tissues of 15 of 30 tested cetaceans that died on beaches in Hawai’i, Samoa, Saipan and at sea. It is not clear that virus was the cause of death in any of these cases, but it has the capacity to cause significant illness in some dolphins and whales. We reported on that in an earlier blog. 

Sperm whales are the largest of the toothed whales, with adults ranging from 40 to 52 feet in length. The Lydgate whale appears to be at the upper end of that range. They can range in weight from 15 to 45 tons, according to NOAA Fisheries.

They are found throughout the world’s oceans, and while their population has increased significantly from the heavy whaling years, they continue to be listed as endangered under the U.S. Endangered Species Act and depleted under the Marine Mammal Protection Act. They are now protected throughout their range.

NOAA estimates that more than 400,000 sperm whales were taken between the start of whaling in 1800 and its end in 1987 in the North Pacific alone, and more in other oceans. 

A study reported last year in Nature estimates that the pre-whaling global population of sperm whales approached 2 million, that it was severely depleted by whaling, and that in 2022, the number had grown back to around 850,000. But the study said those estimates are very uncertain.

© Jan TenBruggencate 2023

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