Limiting Factors in the Success of Habitat Restoration Sites for O. Conchaphila in San Francisco Bay For the: 9 th International Conference on Shellfish Restoration Charleston, SC November 17, 2006 By: Robert R. Abbott, Rena Obernolte MACTEC Engineering and Consulting Inc. & Brian Mulvey Kleinfelder, Inc.

Pilot Project Objectives Demonstrate the feasibility of reestablishing self- sustaining populations Demonstrate the feasibility of reestablishing self- sustaining populations Obtain data to help identify limiting factors Obtain data to help identify limiting factors –Substrate- Predation –Water quality- Disease –Other (circulation, population densities, larval sinks,?) Identify appropriate conditions and methods for reestablishment Identify appropriate conditions and methods for reestablishment Establish connection with tidal marsh? Establish connection with tidal marsh? Develop better understanding of genetics Develop better understanding of genetics

3 Project Locations 3 Project Locations –Marin Rod and Gun Club –Bair Island –Sailing Lake

BAIR ISLAND SITE Near Redwood City In South San Francisco Bay

BAIR ISLAND FEATURES Tidelands adjacent to tidal marsh preserve Tidelands adjacent to tidal marsh preserve –Implications for South Bay Salt Ponds ? -1 feet to -3 feet re MLLW -1 feet to -3 feet re MLLW Oyster drill 1/m 2 (Harris 2004) Oyster drill 1/m 2 (Harris 2004) South SF Bay water regime South SF Bay water regime –Long retention time –Euryhaline conditions –Historical native and commercial oyster utilization

OYSTER DRILLS Only observed in South Bay to date Only observed in South Bay to date High densities at project sites near Bair Island High densities at project sites near Bair Island Many mortalities observed (younger oysters) Many mortalities observed (younger oysters) Overall not much of a limiting factor Overall not much of a limiting factor Other sources of mortalities outweigh drills Other sources of mortalities outweigh drills

2006 Pallet Installation

BAIR ISLAND RESULTS Overall survival at the end of one year higher than other sites (a very wet year) Overall survival at the end of one year higher than other sites (a very wet year) Oyster drills have not been observed to be as limiting as other factors Oyster drills have not been observed to be as limiting as other factors Used extensively by gobies, and opportunistic organisms Used extensively by gobies, and opportunistic organisms Much increased set using hanging bags in 2 nd year Much increased set using hanging bags in 2 nd year –Different environment –Local oyster population now present –Predator access possibly reduced 2006 pallet shell recruited much better than 2005 pallet shell 2006 pallet shell recruited much better than 2005 pallet shell

NOAA Corps, NOAA Fisheries Santa Rosa, and NOAA Restoration Center NOAA Corps, NOAA Fisheries Santa Rosa, and NOAA Restoration Center Marine Science Institute Marine Science Institute USGS USGS California Department of Fish and Game California Department of Fish and Game Volunteers from Save the Bay, SERC, MRGC, local residents Volunteers from Save the Bay, SERC, MRGC, local residents Funding provided by Funding provided by –US Fish and Wildlife Service –Coastal America –San Francisco Bay Joint Venture BAIR ISLAND PROJECT ACKNOWLEDGEMENTS

MARIN ROD AND GUN CLUB SAN RAFAEL In North San Francisco Bay

Marin Rod and Gun Club Site 40 Acres owned fee simple 40 Acres owned fee simple Club members committed to conservation Club members committed to conservation Voted on a three year program Voted on a three year program Phase 1-Strings Phase 1-Strings Phase 2-strings, stakes, pallets Phase 2-strings, stakes, pallets Phase 3-Reef rows Phase 3-Reef rows Eelgrass Eelgrass Recreational anglers Recreational anglers Fish utilization study Fish utilization study Water quality effect on survival Water quality effect on survival

Project Location Map

Recreational Angler CPUE 2006

POTENTIAL LIMITING FACTORS Substrate Substrate Sedimentation Sedimentation Salinity (depth) Salinity (depth) –Mortality –Spawning Competition Competition –Varies seasonally and annually Predation Predation Disease ? Disease ? Dissolved oxygen? Dissolved oxygen? Permits Permits –Considered fill –Large projects difficult to permit (> 0.25 acre)

FUTURE RESEARCH Continue studies of recruitment, growth and survival through time Continue studies of recruitment, growth and survival through time Establish monitoring program for predators and disease (green crabs, oyster drills, etc.) Establish monitoring program for predators and disease (green crabs, oyster drills, etc.) Increase monitoring to include fish and invertebrate utilization of oyster shells and reef structures Increase monitoring to include fish and invertebrate utilization of oyster shells and reef structures Continue trying different substrates, configurations, and variations in time and depth of placement Continue trying different substrates, configurations, and variations in time and depth of placement

Todd Meyer Club, Jerry McEowen, Mike Guenza, Paul Tarzia and Bill Craig and the whole Marin Rod and Gun Club team Todd Meyer Club, Jerry McEowen, Mike Guenza, Paul Tarzia and Bill Craig and the whole Marin Rod and Gun Club team Natalie-Cosentino Manning, Eric Bohaboy and everyone at the NOAA Restoration Center and NOAA Fisheries Santa Rosa Natalie-Cosentino Manning, Eric Bohaboy and everyone at the NOAA Restoration Center and NOAA Fisheries Santa Rosa Over 100 Volunteers from the Marin Conservation Corps and California Conservation Corps, and 4 Bay Area Universities, house wives, Save the Bay, etc. Over 100 Volunteers from the Marin Conservation Corps and California Conservation Corps, and 4 Bay Area Universities, house wives, Save the Bay, etc. Students from 4 Bay Area high schools Students from 4 Bay Area high schools San Francisco Bay Joint Venture San Francisco Bay Joint Venture Kevin Lunny: Drakes Bay Oyster Farm Kevin Lunny: Drakes Bay Oyster Farm ACKNOWLEDGEMENTS

SAILING LAKE Shoreline Park in Mountain View South San Francisco Bay

Sailing Lake 47 acres saltwater recreational lake 47 acres saltwater recreational lake Impermeable clay bottom Impermeable clay bottom Built in 1982 Built in 1982 Up to 16’ deep Up to 16’ deep Bottom DO = 0 ppm at times Bottom DO = 0 ppm at times No predators No predators

SAILING LAKE OYSTER BED

Sailing Lake links with San Francisco Bay via pumps from inner Charleston Slough San Francisco Bay Sailing Lake

Sailing Lake Results Bags of cultch placed on the bottom (4m) for 7 weeks collected approximately 4 spat per cultch shell Bags of cultch placed on the bottom (4m) for 7 weeks collected approximately 4 spat per cultch shell The deepest bags collected the most spat The deepest bags collected the most spat Oysters were evaluated by CDFG before being moved Oysters were evaluated by CDFG before being moved Sailing Lake oysters appear to have better survival than natural sets at Bair Island and Marine Rod and gun Club Sailing Lake oysters appear to have better survival than natural sets at Bair Island and Marine Rod and gun Club