Confirmed sightings of endangered leatherbacks by scientists and naturalists aboard Blue Ocean Whale Watch, HuliCat, and other vessels offshore of Monterey, Santa Cruz, and Half Moon Bay have been reported to our all-volunteer Leatherback Watch Program over the last seven days! Leatherbacks are here!! Visit and “Like” our Leatherback Watch Facebook Page to share stories, see photos, and learn more.

Join us on a leatherback cruise and see if you can see one, too! Offshore cruises are scheduled in August, September and October. See our Events page for exact trip details and registration information.

Hundreds of thousands of California residents learned the news of the arrival of endangered leatherbacks when the San Francisco Chronicle published this story below with a lead-in on the top of the front page of the printed newspaper.

Leatherbacks return on heels of jellies

David Perlman, Monday, July 23, 2012

The Pacific leatherbacks are back.

Whale watchers in Monterey Bay reported last week spotting the extremely rare Pacific leatherback sea turtles while others said they saw them offshore from Monterey, Moss Landing, Half Moon Bay and Santa Cruz.

The huge turtles were grazing on jellyfish, their favorite, the witnesses said.

Marine biologists expect reports of more sightings as the world’s largest sea turtles migrate more than 6,000 miles into their feeding grounds along the California coast from nesting beaches far off in the South Pacific.

Chris Pincetich of the Turtle Island Restoration Network, a nonprofit advocacy group in Marin, said the leatherbacks seen last week appeared to be moving north as they followed a huge bloom of jellyfish. They are feasting on brown sea nettle jellies, the most nutritious species offshore from California, Pincetich said.

At least two leatherbacks were reported by passengers and crew aboard the whale watching Blue Oceans High Spirits out of Moss Landing. A former deckhand on the whale watching boat Huli Cat, out of Pillar Pont Harbor in San Mateo County, also spotted one from shore, said Tom Mattusch, the boat’s skipper.

Leatherbacks were listed as endangered in 1970 under the Endangered Species Act. Their depleted population is still threatened by commercial fishing with long lines and drift nets, egg poaching in their Far East nesting grounds, destruction of nesting habitat, and changing ocean conditions.

Researchers estimate that the leatherback population has declined by 95 percent worldwide since the 1980s.

The annual leatherback migration along the Pacific Coast normally runs from June until October or November.

In January, the National Oceanic and Atmospheric Administration designated nearly 42,000 square miles of ocean along the Pacific Coast as a critical habitat for the leatherbacks, but the Turtle Island group and other environmental organizations have protested that the area does not include all crucial migration routes or adequate protection against commercial fishing.

David Perlman is The San Francisco Chronicle science editor. E-mail: dperlman@sfchronicle.com