Biology Reference
In-Depth Information
uted to the ecological catastrophe at Kesterson National Wildlife Refuge in
1983, where many ducks turned up dead or deformed by selenium poi-
soning. Scientists warn that if the San Luis Drain—the channel that deliv-
ered the contaminated agricultural drainage—is ever connected to the
North Bay as originally planned, it will increase bay selenium concentra-
tions to levels that endanger ducks, fish, and other species. Many environ-
mental groups and agencies now say that retiring large tracts of land with
problem soils is the only sustainable solution.
Down in the urban region around San Francisco Bay, cities and coun-
ties are now pushing storm-water initiatives far beyond the public service
messages and waste motor oil collection of a decade ago. At Brisbane City
Hall, rainwater from the roof and parking lot that used to race into the bay
now flows into a green depression—a “rain garden”—planted with sedges
and rushes (see p. 197). In San Bruno, street runoff flows into a bulb-out
planted with trees and native grasses. In Oakland, a bioswale treats pol-
luted storm water that would ordinarily flow into Lake Merritt. Around
the bay, municipalities are working on ways to slow, spread, and sink the
storm water that used to speed into the bay. These “green infrastructure
projects” mimic how a forested landscape would handle runoff. Regional
regulators now require all new or redevelopment projects over 10,000
square feet to treat their storm-water runoff on-site.
In the twenty-first century, the brew of pollutants turning up in every-
thing from tiny fish to human infants is a reminder that the battle to
keep our bay and environment clean is far from over. Not only do some
“legacy” pollutants never seem to go away—such as mercury from min-
ing days, selenium from irrigated San Joaquin Valley soils, and PCBs
from old dump sites—but moves to ban certain chemicals like flame re-
tardants or pesticides simply lead to their replacement with something
equally problematic for the environment. And industry isn't solely to
blame. Scientists have been disturbed to see personal care products,
medicines, and birth control hormones turning up in organisms, water,
and sediments. They think such contaminants may be the reason some
fish and frogs have been found with indistinct genders and incomplete
reproductive equipment.
“The real issue is the relative costs and benefits of all these chemicals
we're putting in our diapers, plastic bottles, make-up, deodorant, drugs,
furniture, cars—all these different things we use to keep things from catch-
ing fire, to make them smell nice, to stop them from getting moldy, or to
