Help Protect the Chesapeake Bay,
Our Fish and Wildlife and Our Families - by Don Fine*
The Chesapeake Bay Watershed, beginning
north in Cooperstown, NY includes virtually all areas of
Maryland and Virginia and major portions of West Virginia,
Pennsylvania, and Delaware, nearly 64,000 square miles.
The Chesapeake Bay is the world's second largest estuary.
The Bay's ideal land to water ratio, along its hundreds of
miles of shoreline, provide an ideal reproductive area for
aquatic plants and animal species. But even more vast than
the Watershed is the Airshed, that is the area that
contributes "air pollution" to the Chesapeake. In addition
to the states mentioned, the Chesapeake Bay Airshed
includes areas of Ohio, North and South Carolina and
parts of Georgia.
Maryland residents know well the importance of the
Chesapeake Bay to its economy and recreational opportunities.
But how often is the health of the Bay considered as it
relates to human health and why should we be concerned
that pollution of the Bay is affecting us, even if we
do not live near or recreate on the Bay?
At the January meeting of the Antietam Fly Anglers
(January 19, 2006) Mr. Derek Brockbank, Outreach
Coordinator for the National Wildlife Federation
spoke regarding the decline in the health of the
Bay, as a result of mercury pollution and
global warming.
What is mercury and why is it dangerous?
Mercury is one of the basic elemental minerals
normally found in nature (e.g. in coal). But
in an ingested form, mercury is a toxic heavy
metal that can harm the brain and central
nervous system, particularly in infants
and children.
How does mercury get into the water
such as the Chesapeake Bay in the first place?
Mercury occurs naturally in the environment
and can also be released into the air through
industrial pollution. As an example, mercury
is released into the air from power plants
during the process of coal-burning. Mercury
combines with water in the air, then falls
(via rain) and can accumulate in streams
and oceans where it is turned into
methylmercury in the water.
If mercury is normally always around us in
nature why is mercury hazardous to animals and fish, and
particularly to humans?
The toxic effects of mercury depend on its
chemical form and the route of exposure.
Methylmercury is the most toxic form. It
affects the immune system, alters genetic
and enzyme systems, and damages the nervous
system, including coordination and the senses
of touch, taste, and sight. Methylmercury is
particularly damaging to developing embryos,
which are five to ten times more sensitive
than adults.
How does mercury end up in the food chain?
Exposure to methylmercury is usually by ingestion,
and it is absorbed more readily and excreted more
slowly than other forms of mercury. Because it is
excreted more slowly than other forms of mercury,
methylmercury accumulates in higher quantities in
each species in the food chain. For example,
fish-eating birds and mammals (including humans)
would have higher levels of mercury in their
system than the fish they consume. Fish, in turn,
will have higher levels than the smaller bait
that they consume, etc.
What are some examples of how mercury pollution has impacted aquatic species?
High levels of mercury have been found in common
loons and other ducks, where species numbers have
fallen in recent years. Studies have shown that
loons that eat mercury-laden fish hatch 50% less
young, incubate their eggs significantly less
time and produce lighter eggs. Predatory fish
such as rockfish, even walleye and trout, are
susceptible to adverse reproductive effects
from elevated mercury levels. Small and largemouth
bass in Maryland have been found with high
concentrations of mercury in their systems.
What are the concerns for humans?
There is a heightened concern for the health of
humans that might eat fish containing high levels
of mercury. A recent US Environmental Protection
Agency (EPA) report shows that 1 in 6 women of
childbearing age has mercury levels in her blood
above what the EPA considers safe for the developing
fetus. The National Research Council, in its 2000
report on the toxicological effects of methylmercury,
pointed out that the population at highest risk is
the offspring of women who consume large amounts of
fish and seafood. The report went on to estimate
that more than 60,000 children are born each year
at risk for adverse neurodevelopmental effects due
to in utero exposure to methylmercury. The Food
and Drug Administration (FDA) has advised pregnant
women and women of childbearing age who may become
pregnant on the hazard of consuming certain fish
(e.g. shark, swordfish, king mackerel, and tilefish)
that may contain high levels of methyl mercury. As a
matter of prudent public health advice, the FDA is
also recommending that nursing mothers and young
children not eat these fish as well.
What is being done about this threat to
our families and environment?
Maryland has issued a statewide fish consumption
advisory, warning residents to limit their
consumption of fish due to mercury contamination
As citizens what can we do about this situation?
Write to your state legislators and let them
know that you support strong, rapid clean-up
of power plants. Ask them to support the Healthy
Air Act and legislation to reduce mercury,
carbon, nitrogen and sulfur pollution from
coal-burning power plants.
(*The above information on dangers of mercury
in the environment was assimilated from Mr.
Brockbank's presentation along with information
provided the Environmental Protection Agency
and Food and Drug Administration.)
Additional information on Mercury from John Brognard V.P. Conservation MAC-FFF:
First I wish to thank Don Fine for this excellent article!
Additional information on mercury contamination in seafood can be found
at
Oceana.org
Another web site that is aggressively trying to get the EPA to do their job and protect our
children is
Mercury Action Now
You will also find information on
Save the Clean Air