Warm Conditions Prompt Warning of Blue-Green Algae Blooms
With the onset of warm, even hot, weather even in northern
climes, here is a great warning from the Iowa DNR about possible
pitfalls associated with blue-green algae blooms…
Rapidly warming weather and water temperatures have prompted
concerns about microcystin, a product of blue-green algae.
Sun Valley Lake, a private lake and development in Taylor
County, reported a small fish kill on Saturday in an area of the
lake that appeared to have a blue-green algae bloom. The algae can
deplete oxygen, making fish vulnerable, particularly this time of
year when fish are also stressed because of spawning
Sun Valley Lake will be sampled by Iowa Department of Natural
Resources for microsystin. Because the conditions are conducive to
blue-green algae growth, people and pets should not be in contact
with water that has a poor appearance. The appearance can be a
pea-green or blue-green color, but also a reddish-brown. It may
appear with scum, foam or as a thick mat on the water surface.
Blue-green algae can grow quickly and become very abundant in warm,
shallow, undisturbed surface water that receives a lot of
The main risk to humans from microcystin is skin irritations and
rashes, but if the water is swallowed or airborne droplets are
inhaled during swimming, bathing or showering, symptoms could be
worse. Those would include headaches, nausea, abdominal pain,
seizures, liver injury and respiratory problems.
Precautions that should be taken to prevent
health-related problems due to harmful algal blooms
• Don’t swim, water ski or boat in areas where the water is
discolored or if there is foam, scum or mats of algae on the
• If you come in contact with water that might have a harmful
algal bloom, rinse off with fresh water as soon as possible.
• Don’t let pets or livestock swim in or drink from areas where
water is discolored, of if there is foam, scum or mats of algae on
• Don’t let pets (especially dogs) lick the algae off their fur
after swimming in scummy water.
• Don’t irrigate lawns or golf courses with pond water that
looks scummy or has a bad odor.
• Don’t drink the water. Boiling the water will not make it safe