'Rio' The River Whale Makes Hopeful Turn Toward SF Bay, But No Further Sightings Yet

BAY AREA, CA — For days, a humpback whale’s journey up the Sacramento River drew curious boaters and raised questions about how an 80,000- pound cetacean got from a vast ocean into a waterway than can narrow to three-quarters of a mile wide — and only 200 feet in some spots.

Now, researchers think the whale, Rio, has turned toward the ocean, giving them and cetacean watchers reason for hope — though no one has reported seeing the whale since Friday.

Rio, the humpback whale who startled anglers on the Sacramento River was last spotted heading westward toward the Sacramento-San Joaquin Delta.

"It's a positive sign," Marine Mammal Center spokesman Giancarlo Rulli said today.

West is in the direction of the San Francisco Bay and ultimately the Pacific Ocean, but no one knows if Rio made it that far.

The Coast Guard reported seeing the whale off Port Chicago near Suisun Bay on Friday afternoon.

“This is the best news that we could have received that afternoon because that’s the direction we want Rio to go,” Kathy George, the Mammal Center’s director of cetacean conservation, said in an update.

However, the center has received no confirmed sightings since then.

This is not necessarily bad. Rio could already be in open ocean waters, where Humpback whales belong.

SEE ALSO: Whale Deaths Spike In San Francisco Bay

Rio first appeared in San Francisco Bay on Sept. 15. Sightings placed the whale near the Richmond ship channel, north of the Richmond-San Rafael Bridge, and in the Carquinez Strait near Benicia.

By the morning of Sept. 16, the Coast Guard had reported a humpback near Rio Vista in the Sacramento-San Joaquin Delta. Researchers do not know why Rio traveled inland.

'At First We Didn't Believe It'

An angler, Denny Glover, was fishing for salmon and striped bass with friends from a 21-foot boat when one of them spotted a spout.

Glover filmed the adult whale breaking the river’s surface.

“At first we didn’t believe it. We thought he had mistaken a dolphin or a porpoise,” Glover said. “Then we saw the spout again, and there’s no mistaking a whale spout.”

Researchers have documented Rio 15 times over the past 24 years, most recently in Baja California in February, the center said. The whale is more than 20 years old, but researchers do not know whether the Rio is male or female.

George said the center has seen nothing else about Rio’s condition that concerns its team, though the whale was outside its usual habitat.

She urged boaters and paddlers to give Rio space and asked people not to fly overhead in search of the whale.

Other humpbacks have also made the trip inland and returned to the ocean. Humphrey spent several weeks near Rio Vista in 1985, and a mother and calf known as Delta and Dawn spent nearly three weeks in the Delta in 2007.

Humpback whales are among the largest animals on Earth and can weigh up to 80,000 pounds.

They are known for their dramatic lunges at the water's surface, an activity called breaching, and their complex underwater songs.

Seeing the whale so far upriver was a thrill, Glover said. The animal seemed in good shape despite being far from home, he added.

“It came up and went down in fairly regular intervals,” he said. “It was moving along at a fair clip. It wasn't acting erratically other than that it was upstream in a freshwater river.”

Anyone who sees Rio or other cetaceans can report the sighting through the Whale Alert app or the center’s website.

For more whale watching, Pacifica or Point Reyes offer views near shore. The whales may even be feeding there, although George reminded onlookers to give them space.

By TERRY CHEA and PATRICK WHITTLE Associated Press

RELATED:

• Something 'Unprecedented' Is Happening With Orcas Off The CA Coast
• Whales Keep Dying In The Bay Area. A New Bill Aims To Fix That
• A New AI Tool Could Help Prevent More Gray Whale Deaths
• Cause Of Death Revealed For Whale That Refused To Leave LB Harbor
• Something Alarming Is Happening To Gray Whales Off California's Coast
• Human-Related Causes Resulted In Whale Deaths In Bay Area
• 5 Gray Whales Found Dead In Bay Area