Oyster History and Oyster Restoration

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					Predicting the Future of San Francisco Bay: Learning from History




   Does knowing the History of
  Life in the Bay help us with its
            Restoration?


                     Andrew Cohen
              Center for Research on
               Aquatic Bioinvasions
Reactive   • Reducing Damage
           • Preservation




Active     • Restoration
Nichols et al. 1986
Tidal Saltmarsh in San Francisco Bay


 Before 1850          190,000 acres

 1979                  31,000 acres

 2000                  40,000 acres

 Restoration target   100,000 acres
Planting for saltmarsh restoration (from Zedler 1987).
Paul Amato photo
Eco-historical knowledge:


   • Past abundance

   • Why we lost it

   • Details of nature and function
What does Eco-history tell us?




  Olympia oyster Ostrea lurida
“Historically, the native oyster (Ostrea lurida), was present
in the Bay in prodigious quantities.”      —Skinner 1962


“Massive shell middens formerly found around the Bay
indicated that aboriginal people consumed large
quantities of mollusks, particularly the native oyster
Ostrea lurida…Evidence of the rapid decline of shellfish
resources soon after the arrival of the white man is
equally striking.”                        —Nichols 1979


“These oysters were really super-abundant 150 years
ago," said Edwin "Ted" Grosholz, a marine ecology
specialist at UC Davis. “We know that from the harvest
numbers in San Francisco Bay in the late 1800s...At one
time, Olympia oysters littered San Francisco Bay.”
                                —SF Chronicle 4/28/2003
“Gold Rush settlers found the oysters irresistible and
gobbled them up so fast they were just about harvested
out of existence.”       —Sacramento Bee 11/26/2001



“Over-harvesting and degraded water quality have
depleted the native oyster (Ostrea lurida) population in
San Francisco Bay, reducing a once dominant local
fishery resource to a few scattered remnant
populations.”             —Save The Bay Summer 2001



“The vast reefs of the 1800s...were smothered by gold
miners' silt, poisoned by raw sewage and carved up by
Barbary Coast oystermen.” — SJ Mercury News 6/8/2004
“In the past few years, researchers…began noticing an
unfamiliar species...the native oyster of the bay,
seldom seen since the 19th century. Apparently—and
exactly how remains a mystery—the little native oyster
hung on through the hard years of mining debris and
low oxygen...in the bay.”
                —Booker 2006 Pacific Historical Review

“The native Olympia oyster...once dominated San
Francisco Bay’s ecosystem …Due to over harvesting,
loss of habitat, and pollution, oysters virtually
disappeared from the Bay…Indications that oysters
were returning to San Francisco Bay were seen in the
late 1990s when small, scattered populations were
discovered on docks near Redwood City.”
         —submission to Journal of Shellfish Research
        Native Oysters in SFBay

• Abundant        1700s to mid-1800s

                  over-harvesting
• Declined        pollution
                  mining sediment

• Disappeared     late 1800s-1900s

• Reappeared &    1990s
  Rediscovered
Front page of the San Francisco Chronicle, Feb. 4, 1999




                                Front page part
Presence of Native Oysters
 Redwood Creek to Vallejo

year    % of sites   common at

1993    57% of 14        1
1994    77% of 13        1
1996    79% of 14        1
1997    75% of 12        2
   Presence of Native Oysters
           1951-1979
          # of                # of
year   records       year   records
1951     3           1974       7
1962     2           1975       7
1963     2           1976       4
1964     2           1977       1
1970     5           1978       4
1971     1           1979       4
1973     4
Albatross Survey
    1912-13
             Native oysters
             collected at 17
             sites.

 Albatross
dredge map
        Native Oysters in SFBay

• Abundant        1700s to mid-1800s

                  over-harvesting
• Declined        pollution
                  mining sediment

• Disappeared     late 1800s-1900s

• Reappeared &    late 1990s
  Rediscovered
1769   Portola

1776   Ayala & Anza

1834   Independence

1848   Gold

1850   Olympia oyster imported
       from Washington and
       reared in the Bay

1869   Virginia oyster imported
       from East Coast and reared
       in the Bay
SF in 1847
Population of San Francisco

   1794           1,056
   1798             833
   1800             867
   1815           1,488
   1830             350
   1842             196
   1844              50
   1846             200
   1847             459
   1848             850
   1849           5,000
   1850          21,000
   1860          56,802
   1870         149,473
   1880         233,959
   1890         298,997
   1900         342,782
Main Writings on the History of Oysters In California


Barrett (1963) The California Oyster Industry

Skinner (1962) Fish and Wildlife Resources of the San
Francisco Bay Area

Bonnot (1935) The California Oyster Industry

Townsend (1893) Report of Observations Respecting
the Oyster Resources and Oyster Fishery of the
Pacific Coast of the United States

Ingersoll (1881) The Oyster-Industry
Estimated Depth of Sediment (m)
   Deposited from 1870-1896


Suisun Bay & Carquinez Strait    0.30
San Pablo Bay                    0.47
Central Bay                      0.00
South Bay                       -0.05


                  — based on Krone (1979)
  So if it wasn’t overharvesting,
 or pollution, or hydraulic mining
debris that did in the native oysters,

           then what did?
West Berkeley Shellmound
SFChron-Front page.jpg




                  from Story et al. 1966
        Native Oysters in SFBay

• Abundant        1700s to mid-1800s

                  over-harvesting
• Declined        pollution
                  mining sediment

• Disappeared     late 1800s-1900s

• Reappeared &    late 1990s
  Rediscovered

				
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