|"The Fish Journal"
Issaquah Press, Published December 15, 2009
By Dallas Cross
fresh water fish are not only interesting for those who value them
for food or sport, but they are also studied by naturalists, wildlife
biologists, ecologists, public health professionals and even
have a lot in common with fish. We intimately share the same water.
They swim and breathe in it and we drink and bathe in it. Because of
the constant contact with shared water, fish in our lakes and streams
become our aqueous mine-canaries signaling problems in the water that
will adversely affect our own health.
municipalities get their water supply directly from rivers or
reservoirs, or from wells supplied from surface waters. City
water waste, or sewage, is treated to control disease by removing
bacteria, but treatment plants are not designed to take out all the
pollutants, especially toxic chemicals.
the water from treatment plants is often used again by another town
or city for domestic water. There it accumulates additional chemical
contaminants, is treated and dumped back into the stream. In
addition, surface run off water from city streets and industrial
areas add chemical contaminants to the stream.
let us examine some recent observations about the quality of our
waters and the health of the fish that swim in it. Having been an
investigative biochemist I focus on the contamination of water supply
with estrogenic chemicals. These are synthetic, organic chemicals
that affect the health of animals in ways similar to that of natural
estrogen, a human hormone responsible for development of female
traits in animals. Thus, they are called estrogenic chemicals.
chemicals polluting our water come from birth control pills
containing synthetic estrogen, insecticides, our plastic containers,
plastic water pipes, and industrial and household products. A
prominent contaminant is bisphenol-A or BPA, a compound used to
harden plastic. BPA leaches out of virtually all plastic, including
polycarbonate food and drink containers.
what are the fish telling us about these chemical additions to our
shared water environment? Wildlife biologists report that the ability
for salmon and trout to reproduce is adversely affected by the
increase in estrogenic chemical pollutants. In the Columbia River
system there appears to be a hormone-induced sex reversal of salmon
males to females with subsequent generations becoming genetically
rivers near Boulder Colorado, similar sex-reversal was found in white
suckers downstream of waste treatment plants. In tributaries of the
Potomac River in West Virginia, researchers found sites where nearly
all male smallmouth bass had testes with rudimentary female egg
cells. A survey of fish in rivers and streams in the United States
shows that a majority of male bass have acquired feminine
to home, levels of estrogenic chemicals have been measured to be
increasing in Puget Sound and its tributary rivers and streams.
Levels are high enough to not only change the reproductive ability of
trout, but are cited as being able to affect frogs, river otters and
adverse effects of estrogenic compounds in humans are increased
incidences of breast cancer and interference with natural sexual
development. BPA is medically linked to these problems and is found
to be retained in humans a long time after ingestion, in females more
treatment experts tell us that sewage treatment removes a large
percentage of the estrogenic compounds as solid waste. However, the
solid waste sludge is often returned to the soil as fertilizer for
crops which again introduces toxic chemicals into our food and water
supplies. Studies show that estrogenic chemicals in solid waste do
infiltrate into the ground polluting underground aquifers.
new Brightwater treatment plant, being built in Snohomish County to
process King County sewage, is designed to remove more of the
estrogenic compounds than do current plants. So the danger of
pollution by BPA is being recognized by our local governments. There
is also a strong local movement, promoted by the Sno-King
Watershed Council, to
limit and isolate ground water run off from areas that feed our
domestic water supply.
are steps in the right direction to reduce the harmful chemical
contaminants affecting the fish who are giving us an "early
warning." But we all need to help by limiting the use of
products responsible for contamination by BPA. We need to curtail use
of plastic food containers that contain BPA, and reduce contact of
our municipal water with plastic pipes and storage tank linings.
Hearing the increasingly soprano song of our fish, I advise my friends, family, and especially my
grandchildren to buy and keep their food and drink in glass containers ... especially for baby bottles.