St. Paul, Minn.—With Memorial Day right around
the corner, the unofficial start of summer is here. While water enthusiasts and
pets enjoy swimming and boating when the weather is calm and sunny, these
conditions are also perfect for growing blue-green algae, which can be harmful
to both people and animals.
Last summer, blue-green algal blooms were
reported in lakes across the state, from near the Iowa border all the way to
the Canadian border. The Minnesota Pollution Control Agency (MPCA) and
Minnesota Department of Health (MDH) staff jointly investigated two reported
human illnesses and multiple dog deaths following exposure to blue-green algae.
Blooms typically begin to form in June when the weather warms, but with the
mild spring weather this year, blooms may already be present in Minnesota
lakes.
People
and pets at risk
The appearance of a blue-green algal bloom and
the unpleasant smell that occasionally accompanies a bloom typically keep most
people out of the water. However, people can become sick after they swim, boat,
water ski or bathe in water that has toxic blue-green algae. During these
activities, people are exposed to the toxins by swallowing or having skin
contact with water or by breathing in tiny droplets of water in the air. “In
most people, symptoms are mild and may include vomiting, diarrhea, rash, eye
irritation, cough, sore throat and headache,” said MDH Epidemiologist Stephanie
Gretsch.
Dogs are at particular risk, as they are more
likely to wade in the areas of a lake where algal scum accumulates and humans
avoid. Dogs are usually exposed to larger amounts of toxins from algae because
they tend to swallow more water than humans while swimming, especially when
retrieving toys from the water. They also lick their coats upon leaving the
water, swallowing any algae that may be on their fur. Dogs exposed to
blue-green algae can experience symptoms such as vomiting, diarrhea, rash,
difficulty breathing, general weakness, liver failure and seizures. In the
worst cases, it can cause death. If your dog experiences any of these symptoms
after visiting a lake, seek veterinary care immediately.
Tips
to protect yourself and your pets
Not all blue-green algae are toxic, but there is
no way to tell whether a bloom is toxic by looking at it. Harmful blooms often
look like pea soup, green paint or floating mats of scum and sometimes have a
bad smell. However, harmful blooms aren’t always large and dense and can
sometimes cover small portions of the lake with little visible algae present.
Before you or your children or pets enter the water, take a closer look at the
lake and check for algae in the water or on shore to help determine if a bloom
recently happened.
“If it looks and smells bad, don’t take a
chance. We usually tell people: If in doubt, stay out,” said Pam Anderson, MPCA
Water Quality Monitoring Supervisor. “If you’re not sure, it’s best for people
and pets to stay out of the water.” If you do come into contact with blue-green
algae, wash off with fresh water immediately, paying special attention to the
areas your swim suit covered. Rinse off pets with fresh water if you think they
swam in water where blue-green algae were present.
Addressing
the algae problem
There are currently no short-term solutions to
fix a blue-green algal bloom. Once a bloom occurs, the only option is to wait
for the weather to change to disrupt the algae’s growth. “With intermittent
rain, followed by high temperatures, blue-green algal blooms will be common on
many Minnesota lakes this summer,” said Steve Heiskary, an MPCA Research
Scientist.
The key to solving algae problems is to improve
overall water quality by reducing how much phosphorus gets into lakes.
Phosphorus is a nutrient that encourages plant growth, and it is present in
soil and plants. Runoff
from urban and agricultural land
contains phosphorus. Excess phosphorus in lakes provides the food necessary to
produce algal blooms. Aside from limiting applications of fertilizers that
contain phosphorus, homeowners can help protect our lakes by sweeping up lawn
clippings and soil off sidewalks and pavement, and cleaning up pet waste, so
that rain storms don’t wash the material into nearby lakes and rivers.
More
information on blue-green algae, including how to report a possible human or
animal illness, is available on the MDH Harmful
Algal Blooms website.
Broadcast version
The Minnesota Pollution Control Agency and the Minnesota
Department of Health are advising the public to stay out of algae-laden water.
This year’s mild spring weather has created ideal conditions for algal blooms.
Certain species of blue-green algae contain potent toxins that
can quickly become deadly to both people and animals. Keep pets and children
away from waters with a pea soup or green paint appearance. Water may also have
a foul odor. Symptoms can include vomiting, diarrhea, headache, eye irritation,
and seizures. If you or your pets experience these symptoms, seek medical or
veterinary assistance immediately.
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The mission of the MPCA is to protect and improve the environment and enhance human health.
St. Paul • Brainerd • Detroit Lakes • Duluth • Mankato • Marshall • Rochester • Willmar www.pca.state.mn.us • Toll-free and TDD 800-657-3864
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