We know you care about San Francisco Bay, so we’re asking for your support of our efforts to restore the Bay’s subtidal and intertidal habitats. We need your help in our efforts to determine if we are bringing back native oysters in a sustainable way. Are we increasing species diversity? Are we helping salmon and other species?
To answer such important questions, our partner-scientists from the San Francisco Native Oyster Working Group helped us design a community-based monitoring program. It requires training volunteers and the use of sophisticated technology and scientifically reliable processes to assess the success of our oyster reefs at Pt. Pinole.
Even with the help of dedicated volunteers, oyster restoration–including monitoring–is expensive. The costs of equipment and volunteer supervision adds up to a hefty price tag. We’ve already received support from The Nature Conservancy, NOAA, the U.S. Fish and Wildlife Service, and the Contra Costa County Fish and Wildlife Committee. But in these economic times, they haven’t been able to fund us to a level that covers all the costs. That’s why we need your help in raising an additional $10,000. To explain why it’s crucial (and how we can tell if the salmon are knocking at our door) let’s start from the beginning…
Just 200 years ago, the San Francisco Bay Estuary was fantastically rich in natural resources. It was undisturbed, unpolluted, and teeming with wildlife. Beneath the surface of the Bay, 100,000 acres of filter-feeding native oyster beds cleaned the entire volume of water in the Bay in just a few days while providing physical structures as habitat for many forms of life. At the same time, untold acres of eelgrass meadows provided habitat for myriad other underwater species. Together, these two keystone species were the heart of a Bay food web that–among other things–sustained abundant populations of fish, including salmon.
Sadly, with the arrival of Europeans, human activity greatly degraded the Estuary. Today, native oysters cover less than 10 acres of the Bay’s floor, and our salmon fishery hangs on by a quickly unraveling thread.
During their annual migration through the Bay, from freshwater to the ocean, salmon (now called smolt) need to eat and grow enough to face the rigors of life in the ocean. Unfortunately, the Bay’s subtidal is so degraded that ocean-bound smolt leave the Bay in worse condition than when they entered it. To be sure, restoring salmon requires changes outside the Bay–such as limits on ocean fishing and upstream freshwater habitat restoration–but restoring habitat in the Bay is also crucial.
Helping salmon is a key reason for our work in the subtidal. But how can we tell if we’re helping them? Here, technology provides an answer. First, key fish species (salmon, sturgeon, and striped bass) are tagged–upstream–with tiny transmitters. Each tag has a unique ID and each fish/tag pair is entered into a database. Tagged fish are detected when they get close to any node in a network of submerged receivers located throughout the Estuary. With your help in procuring our own receivers, we’ll know if the salmon are knocking!
Our monitoring plan calls for five receivers: one at each of our four reefball plots and one at a reference location that’s not close to any of our oyster reefs. When a tagged fish gets within range, our receivers will log about two transmissions/second. After we retrieve the receiver from the Bay and download its data, we can tell how many fish came to our reef, how long they spent there, and how often they came back. By comparing the data from our reef receivers with the data from the reference site, we’ll know if the salmon are spending time at our reefs, presumably finding food and shelter from predators.
Please consider investing in the long term health and vitality of the Bay–one of our most important and prized natural resources. Your help is an important contribution to improving the science and process of bay restoration efforts.
Thank you for helping us restore oysters in the Bay. You’ll be helping open the door for the salmon!
Photos of the volunteer oyster monitoring program by: Mary O’Brien (top) and Chris Lim (middle and bottom).