THE waters of Long Island Sound look clear from this central part
of the island where teens fish for small snapper. But looks do not
always tell the full pollution story.
At the center of debate over the seriousness of pollution in the
Sound are questions about the effect of the heavy supply of
nutrients pouring into its western part - and what, if anything,
should be done about them.
Their effect on low dissolved oxygen levels in deep water, a
condition known as hypoxia, is the central focus so far in the
massive, federally funded Long Island Sound Study (LISS), underway
since 1985 and due to be completed next fall.
Sometimes called "the urban sea," Long Island Sound sits in the
most densely populated region of the United States. Each day 1
billion gallons of treated sewage from plants in New York and
Connecticut flow into the Sound. When rainfall is high and sewers
overflow, raw sewage and rain water go in, too.
Studies show problems
Many experts say that the added nitrogen from treated sewage can
damage or kill fish and shellfish in bottom waters or force them to
flee to areas where oxygen is more abundant. Hypoxia occurs
naturally to some degree in summer as warm surface water forms a
distinct layer over colder bottom water, and oxygen in surface water
is prevented from replacing that used by marine life below. Added
nutrients can speed up and intensify the oxygen loss by fueling the
growth of single cell marine plants in surface waters. When the
algae dies and drops to the bottom, it uses scarce oxygen there as
In an interim report issued late last year, the LISS, a study
overseen by the US Environmental Protection Agency, urges that
treatment plant discharges of nitrogen into the Sound be restricted
to 1990 levels.
Environmentalists say the recommendation should include a
timetable. "We think the process of capping nutrients should be
started now so that we aren't continually increasing the amount of
nitrogen that goes into the Sound," says Jane Moffat, coordinator of
the Long Island Watershed Alliance. It is a coalition of 60 groups
that grew out of a series of National Audubon Society hearings on
the Sound last year.
"We should at least keep the situation from getting any worse,"
agrees Jeff Kane, program coordinator of the Citizens Campaign for
the Environment and a member of the LISS Citizens Advisory
Committee. Yet he says the study has spent too much time, money, and
energy on hypoxia and not enough on other pollutants such as toxic
chemicals and pathogens.
Other recent studies confirm that such problems exist. A National
Oceanic and Atmospheric Administration study of coastal waters found
chemical contamination declining in many areas but still serious in
urban areas such as the Western Sound. A recent Natural Resources
Defense Council report claims the coastal waters of New York,
Connecticut, and New Jersey have the worst bacterial contamination
problem in the US, due largely to outdated sewage treatment systems.
LISS officials insist that other pollution problems will be
studied before the final report is issued. …