Biology Reference
In-Depth Information
are beginning to evaluate what they add to aquatic environments via toi-
lets, sinks, gardens, garages, and flameproof furniture. Equally important
to bay health are all of the products residents buy, the hours they drive, the
lawns they fertilize, and the pests they exterminate. With wild and urban
areas in such close juxtaposition around the bay, actions that seem insig-
nificant in isolation add up fast when repeated by the Bay Area's seven
million residents.
A yellow metal claw dangles from the crane on the deck of the U.S. Army
Corps vessel
Raccoon
, ready to snatch from bay waters floating logs, con-
struction materials, and garbage that might prove a navigational hazard.
Two such cleanup vessels ply the bay every day. Retired captain Eric Carl-
son remembers an average daily haul of about 80 tons of garbage 30 years
ago but says the waters have gotten much cleaner since. The
Raccoon
is
more adept at pulling out big debris than small bits of trash. Sometimes it
takes the helping hands of an army of volunteers to handpick the trash out
of bay environs. In 2005, Coastal Cleanup Day volunteers picked up
173,000 pounds of trash and 30,000 pounds of recyclable materials from
creeks, rivers, and shorelines in the Bay Area alone.
The presence of so much human refuse takes a major toll on the envi-
ronment. Most insidious of all, however, is plastic trash. Plastic's primary
offense is its longevity. These petroleum products can take many decades
to decompose; any breakdown that does occur typically involves flaking
into ever smaller pieces. Once gone from land, plastic trash is not forgot-
ten. A gull that pokes its head into a six-pack ring, or a sea lion snared by
fishing line, will almost certainly die before its plastic necklace degrades.
Many marine animals mistake floating plastic for edible jellyfish. Laysan
Albatross chicks and adult sea turtles alike have been found dead or starv-
ing, stomachs bloated with nothing but plastic bags.
The organic surfaces of plastics also tend to accumulate pollutants such
as PCBs, DDT, and other chemicals. Anything that eats these ragged bits
absorbs both these chemicals and the plastics themselves—and might it-
self wind up in the contents of a tuna sandwich. A 1997 study showed that
at least 267 marine species worldwide ingest, or are at risk of entanglement
and drowning due to, plastic trash. Closer to home, a 2007 assessment of
trash in Bay Area creeks found that more than half of the refuse consisted
of plastic and Styrofoam. The survey's results led regulators to declare 28
water bodies and bay segments “impaired” due to the presence of trash—
an entirely preventable impairment. Because plastic trash floats, it tends to
