Sunday, January 29th, 2023
Sunday, January 29th, 2023

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Sportsmen Since 1967

Blue-green algae on the increasing bloom in Lake Erie

There’s a little thing that is becoming a big problem in Lake
Erie.

It also has a bad history. Back in the 1960s, some people
proclaimed that Erie was a dead lake. Sewage treatment plants and
factories were dumping tons of waste into its waters. In places,
the waters were thick, oily and putrid. Fish and wildlife were
noticeably absent. People actually avoided some of its shorelines
and water.

In 1972, the federal Clean Water Act was passed. This mandated
that sewage treatment plants and industry had to clean up their
acts. Included in the regulations were provisions for limiting
phosphorous input into Lake Erie. Sewage treatment plants and
factories, called direct point pollution sources, met the
requirements. Individual households also had to get on board with
non-phosphate detergents. This dramatically reduced phosphorous,
which acts as a fertilizer.

With fewer nutrients in the water, the little villain, blue
green algae, disappeared.

It took about 10 years for Lake Erie to recover. Yellow perch
and walleye once again abounded in the lake. The walleye schools
were never larger than they were in the 1980s. Blue-green algae
seemed to be gone, or at least greatly diminished.

Times have changed. The little blue-green pest is back, in
numbers not seen since the 1960s.

“The real story is that blue-green algae is a symptom of an
ecosystem that is not healthy.” said Roger Knight, Lake Erie
fishery administrator for the Division of Wildlife. “It’s kind of
like what we saw in the 1960s, green water with a lot of blue-green
algae floating in it.”

So, what is the problem with blue-green algae, except that it
makes the water green? In particular, it starts with the type of
algae that is now dominating. It is called microcystis. It makes up
90 percent of the algae in parts of the lake. In the past 10 years,
more and more phosphorous has been making its way into the lake.
The increase of this chemical has led to a blue-green algae
explosion.

The enriched microcystis out competes green algae. In the lake’s
ecosystem, green algae are the good guys and are part of the food
web. Zooplankton eat it, which are then consumed by minnows and
other aquatic life. Blue green algae is not eaten by critters in
the food chain. Worse yet, mycrocystis’s huge population increase
has crowded out the edible green algae.

Under the right conditions, microcystis blue-green algae can
form a toxin. This poison, microcystin, attacks the liver, skin,
and nervous system. Pets drinking water from a lakeshore bathed
with green algae can get sick and even die. If a human drank enough
water containing this toxin, he or she too could die. There have
been no reports of human sickness from drinking Lake Erie
water.

So, what about Lake Erie drinking water that is pumped into
homes? When there is an algae bloom near the water intakes,
additional chlorinated products are used to kill the algae, and
added carbon filters remove it. When a bloom is near the Toledo
water treatment plant, it costs the city several thousand dollars a
day to safely treat the menace. The trick is knowing when a mass of
algae is near.

Last year, $269,000 was spent on a European satellite to follow
blue-green algae movement. This year, a blimp with a super camera
is being used to try and monitor algae blooms more closely and at a
cheaper price. It is essential to be able to keep track of the
algae so as to warn water treatment plants, parks, and swim beaches
of the impending blue-green horde.

Microcystis algae is a serious problem that seems to be growing.
This past summer was the longest period of algae blooms. It started
in mid-May and continued into mid- September.

Not only is the shoreline being impacted, but the lake’s central
basin is negatively affected. A dead zone has formed east of the
western basin. Since nothing is eating the exploding mass of blue
green algae, it keeps increasing in the warm waters. When it dies,
it falls to the bottom and decomposes. This uses up the oxygen in
the central basin’s cold bottom layer of water.

This negatively impacts bottom-dwelling mayfly larvae and
invertebrates that make up a critical part of the food chain. Fish
that don’t suspend may have to leave the area and migrate into
areas without their chosen food sources. This can impede growth
rates and survivability. If the dead zone keeps enlarging, more and
more of the lake will be negatively impacted.

If that isn’t enough trouble there’s another little villain in
Maumee Bay. It’s called lyngbya. It too is a blue-green algae. It
is hairlike and grows on the bottom. Later, it floats to the
surface and can wash onto the shore, forming three- to four-foot
piles of smelly, rotting, debris. Mats of lyngbya float into
marinas and can foul a boat motor’s water intake. Lyngbya has
increased in huge amounts due to extra phosphorous in the
water.

Where is this added phosphorous coming from? The old direct
point sources in the 1960s, sewage treatment plants and factories,
have not increased emissions to the lake.

“Chances are pretty good that some of it is agricultural,” said
Dr. Thomas Bridgeman from the University of Toledo Lake Erie
Research Center. “If it is, what in the agricultural practices has
changed that led to increased phosphorous releases into our
tributaries?”

When one looks at satellite images, one can see large amounts of
algae where the Sandusky and Maumee rivers flow into Lake Erie.
These streams meander through miles and miles of farmlands. It is
called no-point pollution because it doesn’t originate at a
specific point such as a factory or sewage treatment plant.

There is a study being done by the EPA Ohio Phosphorous Task
Force. Since it is thought that farming may be one of the causes,
what practices are they now doing that was not done before? For
instance, no-till farming prevents soil erosion. However, over time
does it allow phosphates to collect on the soil’s surface?

Another factor can be weather. With warmer winters and less
snow, this means more winter rains. Water flowing across frozen
soil can easily wash surface phosphates into ditches and
streams.

However, it should not be assumed that the farming community
gets all the blame. In the suburbs, people are fertilizing their
lawns more. Also, do zebra and quagga mussels play a role?

In the 1970s, we fixed the phosphorous problem. While there is
no scientific proof for this question, might the lack of green
algae negatively impact the available food source for newly hatched
walleye?

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