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Review the indicators
at a glance
- How many marine mammals, turtles, and other animals die in
unusual “mortality events”? For both major groups
of marine mammals (whales, dolphins, and porpoises; and seals,
sea lions, sea otters, and manatees), there were at least three
years out of the last ten in which no unusual mortalities occurred.
Years with high mortalities included 1992 (more than 2500 sea
lions) and 1999 (215 harbor porpoises and 270 gray whales). Data
are not adequate for national reporting on sea turtles, seabirds,
fish, and shellfish.
- How frequent and extensive are harmful algal blooms?
Harmful algae produce toxins that pose a danger to people as well
as to marine animals. Data are not adequate for national reporting
on this indicator.
- What is the condition of small bottom-dwelling animals (worms,
clams, snails, and shrimplike animals)? In 1999-2000,
about three-fourths of the estuary area on the Atlantic and
Pacific Coasts, about half of the Gulf Coast estuary area,
and one-third of the estuary area of Puerto Rico had bottom-dwelling
communities that are considered to be in “undegraded”
condition when compared to a relatively undisturbed site. Between
10% and 25% of the estuary area in all regions is in “degraded” condition
except for Puerto Rico, with about one-third “degraded”.
Data are not available for reporting on these animal communities
outside of estuaries, and there was no clear trend in estuary
conditions from earlier periods.
- What is the concentration of chlorophyll in coastal waters?
Chlorophyll is a measure of the abundance of algae, which are
the source of food, directly or indirectly, for most marine animals,
but too many algae can be harmful to other marine life. Only very
short-term data are available for ocean waters (3 years); additional
data are needed to establish trends. Data are not adequate for
national reporting on estuaries.
Human Use
Four indicators describe the way people use the coasts and oceans.
Three indicators focus on commercially important fish and shellfish:
trends in commercial fish landings; trends in commercially important
fish populations; and trends in chemical contaminants found in fish
and shellfish, which might affect human health. The fourth indicator
tracks contamination of beaches by bacteria from human or animal
waste—a constraint to beach use that complements the core
national outdoor recreation indicator.
- What is the size of the commercial fish catch from U.S.
waters? Since the late 1970s, landings of fish and shellfish from U.S. waters have totaled around 5 million tons per year. Except for Alaska and the region including the West Coast and Hawaii, over this time landings have decreased (the catch in Alaska from U.S. boats has increased). Landings for all U.S. waters combined have decreased from a peak in the mid-1990s. Estimates of catches before the late 1970s are uncertain because of the presence then of large foreign fleets, which are no longer permitted to fish in U.S. waters.
- What is the condition of commercially important fish stocks
in U.S. waters? Overall, about 40% of stocks with known populations
were declining in size and 20% were increasing in size. However,
data are not available on the population trends of about three-fourths
of all U.S. fish stocks.
- What is the concentration of DDT, PCBs, and mercury in fish
and shellfish caught in U.S. waters? Seafood containing high
levels of these contaminants can be harmful to human health, but
data are not adequate for national reporting on this indicator.
- How often are bacteria associated with human and animal waste
found in bathing water at the nation’s beaches? Swimming
in sewage-contaminated waters can cause disease. Data are not
adequate for national reporting on this indicator.
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