Curious about boats — but irascible toward pursuers — gray whales are some of nature’s farthest travelers and a conservation success story.

Gray whales pass through our waters every year, though they’re less common than humpbacks (covered in a previous article in this series). They’re similar in size to that species, with a maximum size of 50 feet and 40 tons. Their scientific name is Eschrichtius robustus: Daniel Eschricht was a Danish biologist, and robustus means “oaken” or “strong.”

Gray whales are baleen whales, which means they have a large filtration mechanism in their mouths. Their primary prey are creatures such as amphipods; these they often capture on the ocean floor, moving sideways along the bottom and sifting the small crustaceans from the substrate (often leaving a plume of sand or mud behind them).

Interestingly, like many cetaceans, they are “lateralized” to one side: like humpbacks, grays are primarily right-handed, as can be seen in the greater wear in the baleen on that side of the mouth.

Gray whales are known today for their curiosity around boats, and numerous tourists have experienced friendly close encounters with them, notably in the Mexican lagoons which constitute their primary breeding and calving grounds.

Yet the sail-based whalers who exploited them in the 19th century had a very different view: grays were known as “devil fish” for their often aggressive responses to boats pursuing them. Indeed, some years ago, one gray whale effortlessly flipped a large 2.5-ton inflatable boat during one of my research team’s projects in the Chukchi Sea.

The species has an interesting distribution. Today, gray whales are confined to the North Pacific. It was not always the case.

Though their range has never included the southern hemisphere, they were once found in the North Atlantic. Sometime around the end of the 18th century, they became extinct there, and it’s apparent from medieval records that they had not been common for quite a while. If they had been, early whalers would almost certainly have recorded taking them.

There are a few mediaeval records that likely represent grays, the most convincing of which is an Icelandic reference in a fascinating 13th century text called “The Kings’ Mirror.”

Yet there are various fossil remains, everywhere from Chesapeake Bay to northwestern Europe. So what happened to them?

Recent archaeological evidence suggests that their demise may well have been caused by prehistoric hunting. We don’t know where Atlantic grays went to give birth (the Chesapeake is one possibility), but if they clustered in coastal areas the way their living counterparts do today in Mexican lagoons, this would have made them vulnerable to primitive hunters.

In a place called Bangudae in South Korea, there are Bronze Ages petroglyphs of whales and whaling that are so detailed it’s possible to identify gray, humpback and right whales in the carvings, suggesting that they were hunted as early as 7,000 years ago.

Gray whales currently hold the record for migration among mammals. In summer, they reside on high-latitude feeding grounds; this range includes the Pacific Northwest, though most whales travel to the waters of the Bering, Beaufort and Chukchi Seas. In winter, grays from the eastern North Pacific migrate to tropical waters to give birth and to mate: most travel along the coast from Alaska to Mexico.

But the record holder was a whale that was tagged with a satellite transmitter off Sakhalin Island in Russia (where my wife Yulia got her start in whale research): a then-nine-year-old female named Varvara traveled from the Okhotsk Sea to Mexico and back, a round-trip distance of a staggering 12,000 miles.

Gray whales were hunted commercially for many years, and by 1936 were so depleted that they were protected by international agreement. The population may have been reduced to a few hundred, but since then they have become a conservation success story, and in 1994 were removed from the U.S. list of endangered species.

Today, eastern gray whales likely number around 20,000, though their abundance fluctuates with environmental conditions; in years when unfavorable oceanographic conditions make prey more scarce, many animals — notably young ones — die. The emaciated whale that washed ashore on the east side of Vashon in April is a good example.

In contrast, there is a very small and highly endangered western population that feeds off Russia; its wintering grounds are unknown, but may have been historically along the now highly developed Chinese coast.

Although grays sometimes pass by Vashon, they are more common off the outer coast off Cape Flattery. There, they were once the focus of native whaling by the Makah Tribe, who have recently attempted to revive that traditional hunt; the tribe’s Treaty of Neah Bay explicitly protects their right to take whales.

Although one whale was taken in 1999 (the first in 70 years), the hunt has been stuck in regulatory limbo for decades. However, the National Oceanic and Atmospheric Administration in June gave the Tribe a waiver for limited hunting of up to 25 gray whales over a 10-year-period. The Tribe will still need to work with federal regulators and obtain a hunt permit.

Due to global climate change, the separation between the Pacific and the Atlantic is disappearing with melting arctic ice. In 2010, a gray whale showed up in the Mediterranean Sea. This wayward animal had apparently entered the North Atlantic via either the Northwest Passage or the Northern Sea route above Russia.

This was clearly an anomaly; however, with the current rapid melting of polar ice, it’s entirely possible that gray whales will one day colonize the Atlantic once again.

Phil Clapham is a whale biologist who lives on Maury Island. Prior to retiring in 2019, he directed the Cetacean Assessment and Ecology Program at NOAA’s Alaska Fisheries Science Center in Seattle.