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Species Affected by Contaminated Sediments
Sediments are home to a wide variety of aquatic life, including
worms, clams, mussels, crustaceans, and insects. Field observations
suggest, and laboratory tests confirm, that contaminated sediments
can be lethal to benthic organisms such as crustaceans and
insect larvae. These creatures occupy important positions
on the food chain that leads up to larger fish like trout,
bass, and salmon and to fish-eating wildlife such as mink,
pelicans, cormorants, and bald eagles.
If the smaller animals lower on the food chain die due to
toxic contaminants in the sediment, the larger animals further
up the chain will lose their supply of food. On the other
hand, if the smaller animals accumulate toxic contaminants
in their tissue and survive, the larger animals may take in
dangerous levels of toxins when they eat the smaller ones.
People can be exposed to dangerous levels of toxic contaminants
when they eat animals high on the food chain, such as salmon
and trout. There also is the potential for exposure to toxic
contaminants through direct contact with contaminated sediments.
Anglers, hunters, waders, and swimmers could be at risk.
Concerned about biomagnification, the increased accumulation
and concentration of contaminants at higher levels of the
food chain, many consumers wonder whether they should continue
to eat fish. The answer is not a simple yes or no. Fish is
a good source of protein and other nutrients, and commercial
seafood typically comes from unpolluted areas. But, people
should avoid eating unsafe amounts of fish that might be contaminated.
Anyone planning a recreational fishing trip, or who regularly
eats fish caught from one body of water, should check with
the state health department to learn if any fish-consumption
warnings or advisories are in effect. Some advisories highlight
groups that are at special risk, including young children,
the elderly, pregnant and nursing women, and individuals whose
immune systems are impaired. The fact sheet Update: Listing
of Fish and Wildlife Advisories (EPA-823-F-98-009) contains
more information on fish consumption.
EPA's database, Listing of Fish and Wildlife Advisories
(LFWA), contains all available information on current
fish-consumption advisories in the United States and Canada.
It also contains wildlife advisories for other species such
as frogs and turtles. The database is available on the Internet
at http://www.epa.gov/waterscience/fish.
Please note that not all fish and wildlife advisories are
related to contaminants in sediment; some advisories are due
to contaminants in other places, like water itself.
contaminated sediment home |
sources |
locating contaminated sediments
species affected |
protecting sediments from contamination
management options |
preventing contaminated sediment
glossary |
acronyms
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