Toxic Algae (Cyanobacteria)

Current Toxic Algae Advisories and Issue Dates:

There are three advisory levels: Caution, Warning, Closed.

Waughop Lake - February 18, 2009 - Warning
Bay Lake - May 21, 2009 - Caution
Clear Lake - November 16, 2009 - Caution
American Lake - December 23, 2009 - Caution

Lakes with advisories are generally checked weekly until advisory is lifted.

Sign up to receive lake advisory updates via e-mail by clicking here and selecting Lake Advisories.

Toxic Algae

Some toxic algae, also known as cyanobacteria or blue-green algae, can produce toxins. These toxins may kill pets, waterfowl, and other animals. They can also cause serious illness or even death in people. Toxic algae are naturally occurring but likely have increased due to impacts from human activities.

What Is A Toxic Algae Bloom?

Toxic algae can reproduce rapidly in fresh water when the amount of sunlight, temperature and nutrients are sufficient. Within a few days a "clear" lake, pond or ditch can become discolored with algae growth. This is called a bloom. Toxic algae blooms often float to the surface and can form a surface scum. This scum, or heavy concentration of algae, can look like green paint and be several inches thick near the shoreline (click here for an example). Wind and weather conditions can greatly change the amount and location of algae.

A heavy concentration of Toxic algae:

Often looks like green paint floating on the surface of the water (click here for an example).

Look like small dots in the water that are hard to pick up or hold.

Can be many shades of green, bluish, brownish or reddish green.

Most commonly occurs in the summer and fall but can occur any time.

Symptoms:

Swallowing lake water containing toxic algae or prolonged skin contact may result in illness, such as muscle weakness, vomiting, diarrhea, and/or nausea. If you know or believe someone may have swallowed water containing large amounts of algae, it is extremely important to seek medical attention.

Toxic algae can cause a skin rash that develops after being in the water. This is a different rash then that caused by Swimmer's Itch.

The risk to pets is much greater than the risk to people, both due to the smaller body sizes of pets and to a pet being more likely to drink water containing a heavy concentration of algae. If a pet does ingest a large amount of algae and is showing signs such as vomiting, lethargy, disorientation, or seizures, it should be taken to a veterinarian as soon as possible.

What If I See An Algae Bloom?

As soon as you notice an algae bloom or possible signs of poisoning:

Keep children and pets away from areas that have a heavy concentration of algae (Looks like green paint).

Do not swim, wade, fish, or water ski in areas that have a heavy concentration of algae (looks like green paint).

Keep all pets and livestock away from the water.

For more information, or to report a suspected algae bloom, please call the Health Department at 253 798-6470 or e-mail us at EHSurfaceWater/Shellfish@tpchd.org.

Last Updated: Jan 14, 2010 3:36 PM