AR-News: (CA) Glimmer of hope in bay's grim report card Ecological
damage seems to be slo
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Mon Oct 13 10:11:02 EDT 2003
The San Francisco Bay is getting an ecological report card today -- and it
doesn't look good. But there's hope behind the C's, D's and an F, according to
the nonprofit environmental group that graded the bay's health.
New laws and regulations that cut down on water pollution and a Bay Area
campaign to restore wetlands are just beginning to stabilize 150 years of decline
in the bay's once-abundant native fish and wildlife populations, according to
the Bay Institute of San Francisco.
"The destruction of San Francisco Bay's unique environment has in some cases
been halted or even slightly reversed," said Grant Davis, Bay Institute
To measure the health of the bay, scientists with the Bay Institute in Novato
spent three years examining such things as wildlife habitat and pollutants,
and prepared the Bay Index 2003. Scientists also looked at freshwater flows
from the Sacramento and San Joaquin rivers and the numbers of fish, shellfish and
the microscopic plankton that feed these higher forms of aquatic life.
The bay's grades -- one B, three C's, three D's and an F -- were based on
historical conditions, environmental and public health standards, and restoration
targets, according to the institute.
Scientists found that native fish and wildlife populations have drastically
declined, while non-native species have invaded the bay. Fish caught in the bay
are unsafe to eat and pollution has risen; freshwater flows and wetland
habitat have been reduced.
But the findings were not all bleak.
"Fish and wildlife populations that were crashing now appear to be stable.
Many people are working to protect and restore habitat, improve water quality
and use resources more efficiently. But progress is slow and needs to be
accelerated," Davis said.
The scientists compiled and analyzed data gathered from state and federal
agencies, and invited national experts on estuaries to review their findings.
Tina Swanson, fish biologist and member of the science team working with the
Bay Institute, said decades of diversions of Sacramento and San Joaquin river
hwater to growers and cities have taken a heavy toll on native aquatic species
in the bay.
Historically, during rain and snowmelt, the fresh river waters have flowed
into the bay and out the Golden Gate. The rush of the rivers creates a special
mixing zone where the freshwater hits the salty ocean water, providing an
important nursery for many estuary species, scientists say.
"The bay suffers from a permanent drought because so much water is diverted
from its watershed," said Swanson. The species are not recovering from the
steep decline they experienced over the last several decades, she said.
Larry Kolb, assistant executive officer of San Francisco Bay Regional Water
Quality Control Board, praised the new scorecard, saying, "If we're going to
spend money restoring the bay, we need ways to tell if we're succeeding or not.
And this is a big step in that direction."
Among the findings:
-- Between 1980 and 2001, the abundance of native fish declined by 50
percent. The long-term downward slide is associated with less freshwater to the bay,
wetland and other habitat loss, and a decrease in plankton in Suisun Bay.
-- In the spring, when fish need fresh flows to the bay from the Sacramento
and San Joaquin rivers, the bay's share of water has been cut as much as 75
percent since 1940, before the completion of major state and federal projects
that divert water.
-- Tidal marsh has decreased since the Gold Rush era from 190,000 acres to
40,000 acres. Since the mid-1990s, public agencies and private groups have
acquired 40,000 acres, and at least two-thirds of these acres are slated for
restoration in the next 30 years.
-- In Suisun Bay since the mid-1970s, phytoplankton -- microscopic plants --
have declined 80 percent, and rotifer zooplankton -- microscopic animals --
have dropped 98 percent. The declines also were associated with a scarcity of
freshwater and an increase in non-native species in the bay.
-- Juvenile Dungeness crab have increased dramatically over the last five
years. But commercial landings are still only about 20 percent of the levels in
the 1940s and 1950s. Numbers of rock crab and bay shrimp have increased in
recent years but have leveled off.
-- The bay's open waters are cleaner than they were 30 years ago, but no
progress has been made in the past decade. Less visible but more persistent toxic
chemicals such as mercury, copper, selenium, nickel, pesticides and PCBs
continue to be found at levels that violate water-quality standards in some
-- In 2000, 94 percent of all bay fish sampled were contaminated with PCBs,
mercury, DDT or chlordane pesticides at levels that made them unsafe to eat. In
2002, bay beaches were reported posted or closed for 50 days, a doubling over
-- Bay Area residents used water more efficiently, but the average person's
use of 95 gallons a day fell short of the conservation target of 66 gallons a
day. Municipalities recycled 68 percent of the amount targeted for reuse.
The scorecard may be viewed at www.bay.org.
SAN FRANCISCO BAY REPORT CARD
The grading system compares conditions in the bay and its watershed to
historical conditions, environmental and public health standards and restoration
Habitat: Bay habitat loss is slowly being reversed, but it could take nearly
200 years to reach the tidal marsh restoration goal.
Freshwater inflow: Reduced inflows are still degrading the bay ecosystem, and
recent gains from wetter years and new standards are being eroded.
Water quality: Open waters are cleaner, but standards are not met in parts of
the bay. Toxic sediments and storm runoff are a major problem.
Food web: Plankton levels in the upper bay have crashed, reducing food
sources for fish and birds. Alien species are locally dominant.
Shellfish: Crab and shrimp numbers are increasing, but commercial harvest is
still down from previous high levels.
Fish: After a long decline, fish populations are stable at low levels, but
some species are still endangered.
Fishable-swimmable-drinkable: Fish are harder to catch and unsafe to eat.
Beach closures are up, drinking water violations are down.
Stewardship: Water conservation, pollution limits, monitoring and restoration
efforts are finally under way, but progress is slow.
Source: Bay Institute of San Francisco
E-mail Jane Kay at jkay at sfchronicle.com
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