Chonkers, the roughly 2,000-pound Steller sea lion who became a local celebrity after an unusual two-month stay at Pier 39, was last seen at K-Dock around early May. Experts say he likely headed for seasonal breeding grounds near the Farallon Islands — and may or may not return.

The spot on K-Dock where a roughly 2,000-pound Steller sea lion spent nearly two months this spring is occupied, when it's occupied at all, by California sea lions — the familiar, smaller residents who've hauled out on those floating planks since 1989. The giant is gone. Visitors arriving in July hoping to find Chonkers are finding something else.

"We're getting a ton more foot traffic," a Pier 39 marina maintenance worker told National Geographic during the animal's stay. "I've been asked multiple times like, 'Hey, where's the Steller sea lion?'" The question hasn't stopped since the animal was last seen at the pier around early May 2026.

Chonkers — a nickname that originated on Reddit and spread to local media, then to national outlets — arrived at Pier 39 on March 13, 2026, and stayed. A Pier 39 spokesperson told ABC7 News that the sea lion had been making intermittent visits to the area for about 15 years, typically for only a few days at a time. This spring, the animal settled in for nearly two months, long enough that the Marine Mammal Center produced a dedicated sign and a plush toy in his likeness during the stay. The distinction between species matters: Steller sea lions are substantially larger and considerably rarer at Pier 39 than the California sea lions that make up the docks' regular population, and Chonkers, at an estimated 2,000 pounds, was hard to miss against the smaller animals around him.

"They're in winter mode, just getting fat. They're not breeding... So he's just hanging out," Jamie C.W. Melin, a wildlife biologist with NOAA Fisheries, told National Geographic. The hanging out ended when breeding season arrived.

Steller sea lion breeding runs from late May through July at rookeries stretching from Southeast Alaska down to California's outer coast, according to NOAA Fisheries stock assessments. Pier 39 is not one of those sites. Daniel Costa, a professor of ecology and evolutionary biology at UC Santa Cruz, told ABC7 News he suspected Chonkers had moved on to establish breeding territory. "I suspect that he is now at the Farallon Islands, right off San Francisco, or maybe even Año Nuevo Island," Costa said. On the question of return: "We could see him tomorrow. We could not. We might not see him for months. He might not ever come back."

There was a brief case of mistaken identity. Reports of a large sea lion on the docks prompted speculation that Chonkers had returned, but Sue Muzzin, a Pier 39 spokesperson, confirmed the animal was a California sea lion — large for its species, not a Steller.

The California sea lions at Pier 39 follow their own seasonal calendar. The dock population hit a recorded high of more than 2,100 animals in late May 2024, then vanished within 48 hours as the colony migrated south to Channel Islands breeding grounds. "It was over a 48-hour period," Pier 39 harbormaster Sheila Chandor told SFist. "Once the really big guys started moving on, everyone else followed. Which is very normal and not unexpected." That population typically returns starting in late August or early fall; mid-July tends to be thin.

What a visitor finds at K-Dock this week: a scatter of California sea lions, considerably smaller than the one that drew the crowds this spring, resting in the sun. The dock has been occupied since 1989. The big exception left in May.