Ventura
County Star
Basic baylands facts
July 21, 2002
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The baylands exist
around San
Francisco Bay between the lines of high and low tide. They are the lands
touched by the tides, plus the lands the tides would touch in the absence
of any levees or other unnatural structures.
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There are 73,000
acres of tidal baylands and 139,000 acres of diked baylands.
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There used to be 23
miles of sandy beaches. Now there are about 7 miles of beaches. Most of
the current beaches are in different locations than the historical
beaches.
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There used to be
190,000 acres of tidal marsh with 6,000 miles of channels and 8,000 acres
of shallow pans. Now there are 40,000 acres of tidal marsh with about
1,000 miles of channels and 250 acres of pans.
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Only 16,000 acres of
the historical tidal marsh remain. The rest of the present tidal marsh has
naturally evolved from tidal flat, been restored from diked baylands or
muted by water control structures.
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There used to be
50,000 acres of tidal flat. Now there are 29,000 acres of tidal flat. The
reduction is due to bay fill, erosion and tidal marsh evolution.
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There used to be
about 174,000 acres of shallow bay and 100,000 acres of deep bay. Now
there are 172,000 acres of shallow bay and 82,000 acres of deep bay. About
16,000 acres of deep bay have become shallow and 18,000 acres of shallow
bay have become tidal, diked or filled baylands.
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The total area of
high tide downstream of the Delta used to be about 516,000 acres. Now it
is about 327,000 acres.
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The total amount of
shallow ponds in the baylands and in the adjacent grasslands used to range
from 16,000 acres to 22,000 acres, depending on the amount of rainfall.
Now there are between 63,000 and 92,000 acres, depending on rainfall and
water management practices. The increase is due to ponding in diked
baylands.
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One-hundred
thirty-seven thousand acres of baylands have been diked.
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Fifty thousand acres
of baylands have been filled.
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There are about 500
species of fish and wildlife associated with the baylands. Twenty of these
species are threatened or endangered with extinction.
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About 7 million
people live around the baylands.
Source: San
Francisco Bay Area Wetlands Ecosystem Goals Project
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