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.
• 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
  
  

   

  Eelgrass (Zostera marina) Fact Sheet

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

Waterbirds [top]

Hundreds of thousands diving ducks and other waterfowl converge on the San Francisco Bay Area (the Bay) during the winter months. The Bay provides wintering habitat to 44 - 50% of diving ducks species along the Pacific Flyway and has been designated an Important Bird Area. These birds rely on the Bay to provide critical resources and protection during the non-breeding season. Unfortunately, some diving duck species have shown recent population declines. Surf Scoters (Melanitta perspicillata), for example, have declined by 50-60% in the last 50 years.

Double-crested Cormorants liftoff near Aramburu Island in Richardson Bay. 
(R. Hinz)

To build a conservation strategy that will protect the thousands of waterbirds that use Richardson Bay during the winter, the Richardson Bay Audubon Center initiated waterbird surveys and established a waterbird sanctuary. Our nine-hundred acre sanctuary is closed to all boat traffic from October 1 to March 31 each winter, providing a place of refuge. To better understand the waterbirds that use Richardson Bay and to start constructing a strategy for the protection of waterbirds, regular waterbird surveys were initiated in the Fall of 2006 with the assistance of a group of dedicated local volunteers. Data from these surveys will be used to track populations over time and develop conservation strategies. Continuing to survey waterbirds over the long-term is essential to our understanding of population trends and will help us identify potential reasons for declines.

Volunteer Helen Lindqvist surveys for waterbirds (K.Wilcox).

Richardson Bay staff and volunteers count waterbirds within the Richardson Bay Sanctuary from five land-based viewing points around the perimeter of the Sanctuary. All individual birds are identified, counted and their behavior is recorded. We conduct surveys twice month from October through March every year.

Community volunteerism is an important tool in our work to connect local residents with nature, in addition to providing additional manpower to enact our ambitious conservation projects. We look forward to continuing help from dozens of community volunteers that help us complete these surveys each year, and will also recruit new volunteers. It is a wonderful way to connect to the local bay ecology and to help monitor its health. If you are interested in volunteering please contact Kerry Wilcox ().

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RESULTS (2006 - 2011)

The most frequently detected species included Greater/Lesser Scaup (Aythya marila/affinis), Bufflehead (Bucephala albeola), Ruddy Duck (Oxyura jamaicensis), Western/Clark’s Grebe (Aechmophorus occidentalis/clarkii), Double-crested Cormorant (Phalacrocorax auritus), American Coot (Fulica americana), and Surf Scoter (Melanitta perspicillata). In each year, more than 6,000 individuals were detected within the Sanctuary (Figure 1). On 24 January 2011 we observed over 13,000 individuals, a record for the Sanctuary (Figure 1). The dramatic increase in waterbirds in 2010-2011 season was attributed to the large number of Greater and Lesser Scaup detected. The total number of waterbirds detected in Richardson Bay varied considerably within years but did not did not vary among years, except for the spike in scaup in 2010-2011. Over the last five years, diving duck abundance appears fairly stable within the Sanctuary. Of the species frequently detected none appear to show steep declining trends, although Western/Clark’s Grebes have declined since the 2007-2008 winter season (Figure 2).

Figure 1. The total number of diving ducks and other waterfowl detected at each survey from 2006-20011. The solid marker indicates the date of the survey. Peaks in diving ducks and waterfowl abundance varied over the course of each season.

Figure 2.  Average number (± Standard Error) of species commonly detected within each season. Photos by Peter LaTourrette.

 
Click here for a list of species seen during each 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.