Posted by on March 25, 2005 at 00:43:13:
IF ALL goes according to plan, people walking along the Bay shoreline may see scuba divers at work this summer in the Berkeley North Basin area of Eastshore State Park.
The divers won't be seeking sunken treasure or mining for gold dust washed down from the Mother Lode. Instead, they will be planting about an acre of eelgrass.
It's a pilot project to see if eelgrass can thrive in the North Basin environment, which is a large, shallow, square-shaped body of water bounded by Cesar Chavez Park, the Berkeley Marina, and the Berkeley Meadow.
The project is being funded by Caltrans as mitigation for eelgrass that was lost as a result of construction work on the new San Francisco-Oakland Bay Bridge. East Bay Regional Park District is involved because it operates the Eastshore State Park under a short-term agreement with the state. Other participating agencies include the Corps of Engineers, the Environmental Protection Agency, the U.S. Fish and Wildlife Service, the state Department of Fish and Game, and the Coast Guard. Planning meetings are now under way.
So why should anyone worry about eelgrass? According to Brad Olson, environmental programs manager for the Park District, eelgrass is a nursery for a variety of fish and invertebrates, including Dungeness crab larva, that use it for cover and as a food source. Historically, filling of the San Francisco Bay shoreline has resulted in loss of substantial eelgrass habitat, which in turn affects all the wildlife that depend on it.
Originally, all the mitigation projects were sited in the North Bay. When the park district requested some East Bay projects as well, five different Eastshore State Park sites were examined. The Berkeley North Basin was selected because it is sheltered and seems to have about the right combination of water depth, turbidity and tidal flow.
According to Olson, the pilot project will plant one or two acres of eelgrass along the Berkeley North Basin shoreline. The basin averages about four feet in depth. So the plan is to put in about two feet of medium grade sand. Then the divers will come in June and plant eelgrass in the sand. Eelgrass is supported by water. When the tide goes out, the plant just flattens out until the water returns. Water clarity is a factor, because eelgrass will only grow in deeper water if sunlight can penetrate for photosynthesis.
Once the pilot plot of eelgrass is planted, Olson said, it will be monitored for a year to see if the sand stays in place and the eelgrass survives. If all goes well, 10 or 12 acres of eelgrass will then be planted at North Basin, providing much-needed food and shelter for Bay marine life.
Most of the environmental action will take place out of sight, under water. "The funny thing about this project is that if they do their job right, the public probably won't notice anything at all," Olson said.
HOLIDAY EGG EVENTS: Egg-themed programs are on the agenda this weekend at Tilden Regional Park's Environmental Education Center in Berkeley.
From 10 a.m. to noon this Saturday, interpretive student aide Gina Gargano will host a holiday egg coloring session. The group will visit the Little Farm bunnies, collect some eggs, then do some coloring. It's for ages 7 to 11, there's a $3 fee per youngster, and registration is required. Phone 510-525-2233 to register.
Then from 9 to 10:30 a.m. Sunday, naturalist Jessica Sheppard will lead an early morning egg hunt, first for frog and salamander eggs and then for the kind you can take home. There's a $5 fee ($7 for nondistrict residents), and registration is required. Phone 510-525-2233.
From 1 to 3 p.m. the same day, Sheppard will lead a visit to the Little Farm to find the black sheep, pet a bunny, search for eggs, and learn about Easter customs. This program is free of charge and registration is not necessary.
TILDEN PLANT SALE: Native plant gardeners take note: The annual native plant sale at the Regional Parks Botanic Garden in Tilden Regional Park takes place from 10 a.m. to 3 p.m. April 16.
A variety of beautiful California native plants will be available for purchase. You should bring cardboard boxes if possible, in which to take home your plants. The sale will take place rain or shine. All proceeds benefit Botanic Garden programs.
The garden is at the intersection of Wildcat Canyon Road and South Park Drive. For more information, phone the garden at 510-841-8732 or visit www.nativeplants.org.