Endangered sea life: Trouble the water

By September 17, 2009Uncategorized

Coho salmon

Marin County is home to the largest wild population of endangered coho salmon in North-Central California. The Lagunitas Creek watershed, which flows from Mt. Tam to Tomales Bay, and includes San Geronimo Valley and Olema Valley, has held this honor for many years. Yet, says Christopher Pincetich, Ph.D., watershed biologist for SPAWN–the Marin nonprofit Salmon Protection and Watershed Network–coho populations were likely in the thousands at the beginning of the 20th century and “Now we are lucky to see hundreds returning to spawn. In the winter of 2008-09, fewer than 50 coho are thought to have returned to spawn, one of the lowest adult-coho returns on record for this watershed.” Coho all over the state are struggling due to habitat degradation, loss of habitat to dams and development, and the effects of poor water quality. But SPAWN, at least, is dedicated to the ongoing protection and recovery of endangered coho in the Lagunitas watershed, focusing much of their efforts in the San Geronimo Valley to monitor and protect coho all year round, leading volunteer habitat restoration, staging fish rescues to save baby salmon in the summer, and running naturalist-led “creekwalks’ to see spawning salmon each winter. For more info, visit www.SpawnUSA.org .

Greatest threat: coastal nutrient depletion, desiccating rivers, overfishing

Cuteness factor, on a scale of 1 to 10: 3. Coho have dark blue/green backs with silver sides that turn deep red when it’s time to spawn, returning from the ocean to their native streams without eating (sometimes for several months) to mate… and then die. Cute!

Did you know?: One theory suggests that salmon find their way home to spawn by using their sense of smell, which is hundreds of times more acute than your ground-sniffing hound dog. If they do get lost, they’ll always be welcome in Chiba, Japan, where they are the official state animal.

The name game: Coho salmon are also called silver salmon, sea trout or blueback. We prefer Oncorhynchus kisutch.

Pacific leatherback sea turtle

The Pacific leatherback is a 150 million-year-old species that outlived the dinosaurs–but whose populations have declined by roughly 90 percent in the last 25 years. Since 1970, the leatherback sea turtle–you may know it as Dermochelys coriacea–has been listed as endangered, and many biologists think the Pacific population will become extinct within a mere decade. The largest of all sea turtles, Pacific leatherbacks can grow to over 6 feet in length and weigh nearly a ton. They travel thousands of miles across the Pacific Ocean from Indonesia and Papua New Guinea to the California coast to gorge on jellyfish–and can be seen along the coastlines of San Mateo, San Francisco and Marin counties from August until about November. Sea turtles eat primarily jellyfish, seaweed, crabs, shrimp, snails, algae and mollusks.

Greatest threat: accidental capture, overfishing of food source, egg harvest, alteration and destruction of nesting beaches, ocean pollution (plastic bags look like jellyfish!), net entanglement

Beach babe: Female turtles migrate hundreds of miles between nesting and feeding grounds, eventually returning to the same beach where they hatched to lay eggs.

Lifespan: Most sea turtles live 15 to 20 years, and can live as long as 80 years.

Cuteness factor, on a scale of 1 to 10: 8. One of the most charismatic megafauna, sea turtles are popular among volunteers, researchers, snorkelers and kids.

Danger factor, on a scale of 1 to 10: 2. Sea turtles are fairly mild-mannered but have been known to have a powerful snap when cornered. And it is, of course, illegal to touch them–even for a really good photo.

If you want to see one: The Marin-based nonprofit Sea Turtle Restoration Project and Pacific Environment’s Marin Sanctuaries Campaign are hosting a special all-day Leatherback Cruise to the Gulf of the Farallones National Marine Sanctuary on Oct. 10. Sea turtle experts who’ve been tagging and tracking leatherbacks all month will be on board to talk to the public.