|"The Fish Journal"
Issaquah Press, Published December 15, 2009
By Dallas Cross
Our 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 biochemists.
We 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.
Many 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.
Downstream 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.
So 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 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.
So 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 abnormal males.
In 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 characteristics.
Closer 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 other fish.
Some 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 than males
Water 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.
The 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.
These 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.