Eelgrass
- Work in collaboration with San Francisco State University continues looking at seeding and whole plant propagation techniques and if bat ray fences give the seeds a better chance of survival.
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Work funded by San Francisco Foundation in collaboration with San Francisco State University began in January 2007 to look at how water depth relates to eelgrass restoration success. This work includes:
- Planting eelgrass at four depths (+1, 0, -2 and -3 feet tidal heights)
- Planting seeds, seedlings and whole plants to see which has the highest success rate.
- Modeling bay circulation to look at potential seed dispersal
- Core samples will be taken to look at the differences between species diversity inside and outside eelgrass beds.
- Plans are in place to plant 500 adult shoots and 500 seeds between September 2007 October 2008.
- We are currently mapping the distribution of eelgrass within the Sanctuary using kayaks (rentals donated by Sea Trek) and GPS units.
photos by Chris Ryan
Native Oyster Restoration [top]
- We are collaborating with SFSU, UC Davis, Smithsonian Environmental Research Institute, Save The Bay, NOAA, Kleinfelder, Marin Rod and Gun Club, and the Natural Heritage Institute to standardize our oyster research and begin a large-scale recruitment study throughout San Francisco Bay.
- We are conducting a field experiment in Richardson Bay looking at settlement and recruitment inside and outside eelgrass habitat and at two depths in the water column. We are placing surface and near benthos bags (10 oysters/bag) inside and outside eelgrass habitat and making monthly checks for settlement and recruitment.
- We have begun setting-up and conducting long-term intertidal monitoring of oyster populations and habitat availability at the beach in front of the Lyford house and at Blackie’s pasture.
Fish Monitoring [top]
Our ongoing study will continue from 2006 using fish pots to look at fish species utilizing the eelgrass beds and restoration site. To date we have found 22 different species of fish species in Richardson Bay.
Cabezon
Leopard Shark
Bay Pipefish Black Surfperch
photos by W.Norden
As this graph indicates, we have captured more fish inside the eelgrass bed than outside.
Fish species found in Richardson Bay
- Bay pipefish Syngathus leptorhynchus
- Bat ray (seen only) Myliobatis californica
- Black Surfperch Embiotoca jacksoni
- Cabezon Scorpaenichthys marmoratus
- Chamelian goby Tridentiger trigonocephalus
- Cheekspot goby Ilypnus gilberti
- Crescent gunnel Pholis laeta
- Diamond turbot Hypsopsetta guttulata
- Dwarf surfperch Micrometrus minimus
- Jack smelt Trachurus symmetricus
- Leopard shark Triakis semifasciata
- Northern anchovy Engranlis mordax
- Pacific herring Clupea harengus
- Pacific staghorn sculpin Leptocottus armatus
- Pile Perch Damalichthys vacca
- Shiner surfperch Cymatogaster aggregata
- Starry flounder Platichthys stellatus
- Striped bass Marone saxatilis
- Striped seaperch Embiotoca lateralis
- Threespine stickleback Gasterostreus spp
Water Quality Monitoring [top]
Water quality monitoring sites in Richardson Bay.
The graph above shows how water temperature, salinity and dissolved oxygen change in the Bay over the course of a year.
Waterbirds [top]
Waterbird survey points and boundaries.
Hundreds of thousands of migratory waterbirds such as ducks, geese, grebes and shorebirds converge on the San Francisco Bay Area during the winter to take advantage of abundant food and shelter resources here. In Richardson Bay, nine-hundred acres are closed to all boat traffic from October 1 to March 31 each winter in order to protect the birds that use the area. These submerged lands make up the Richardson Bay Audubon Sanctuary.
In order to better understand the current use of Richardson Bay by waterbird species, compile baseline data for future comparisons and to link analyses to concurrent research being done on eelgrass and oysters, regular surveys were initiated in Fall 2006 with the assistance of a group of dedicated local volunteers. The 2008/09 season is the third winter we’ve collected data under this protocol. These are land-based surveys from five viewing points on the Sanctuary perimeter. All individual birds are identified, counted and their behavior is recorded. Our goal is to perform two surveys per month over the course of the six-month closure period.
Volunteer Helen Lindqvist surveys for waterbirds (K.Wilcox).
Additionally, a separate protocol has been implemented with staff from the USGS-BRD office in Vallejo for finer-scale analysis of the relationships between birds and eelgrass.
Besides this current monitoring, Audubon contracted with PRBO Conservation Science in 2006 to compile an historic bird use summary for Richardson Bay, which will help us to understand long-term waterbird community changes.
For information on getting involved with waterbird surveys, please contact Kerry Wilcox, Sanctuary Manager.
RESULTS
Data collected during the 2006/07 and 2007/08 seasons indicates that the most common species seen on the Sanctuary waters were Western/Clark’s Grebes, Double-crested Cormorants, Buffleheads, Ruddy Ducks and Greater/Lesser Scaup.
Double-crested Cormorants liftoff near Aramburu Island in Richardson Bay. (R. Hinz)
Bufflehead (L), and Lesser Scaup. (US Fish & Wildlife Service)
Female (L) and Male (R) Ruddy Ducks in non-breeding plumage. (Bill Gaboury)
The graph below shows total count numbers for the survey area over the course of two seasons (2006-2008). Black dots indicate survey dates. Eight surveys took place during 06-07, and ten during 07-08.
Waterbird Survey Results 2006 - 2008 - 2009
The following graph compares mean observations per survey for the most common species seen during monitoring surveys.
[SCAUP=Greater/Lesser Scaup, AEGR=Western/Clark’s Grebe, RUDU=Ruddy Duck, BUFF=Bufflehead, AMCO=American Coot, GULLS=Gull species, DCCO=Double-crested Cormorant, SUSC=Surf Scoter]
Click here for a list of species seen during 2006-07 season.
This page will be updated as further analyses provide us with greater insight into the dynamics of these populations and how they relate the Bay ecology as a whole.
