Summer is Blue-Green Algae Season
Wednesday, June 13, 2012 - 8:07am
Avoiding Contact is Best Way to Avoid Problems
Based on recent news reports and Public Health beach closing notices, this year's blue-green algae season has clearly begun. The safest response when you see a bloom is to keep yourself, your children, and your pets out of the water and avoid all contact.
While blue-green algae often occurs intermittently throughout the summer season, the dry, hot, and sunny weather forecasted for the next seven to ten days may create favorable conditions for increased blue-green algae blooms on area waterways.
Blue-green algae are actually not algae, but photosynthetic bacteria (sunlight-loving) known as cyanobacteria. Some of these bacteria are capable of producing toxins. Exposure to these toxins can produce a range of reactions, from rashes and lip blistering to negative effects on the liver and nervous system. It can include sore throats, headaches, muscular and joint pain and asthmatic and gastro-intestinal symptoms. Dogs swimming in or drinking water covered with a bloom can suffer near fatal or fatal consequences.
If you believe you have been exposed, contact your health care provider right away. You should also report this to a lifeguard and call Public Health at (608) 266-4821.
Blue-green algae occur naturally in lakes, streams and ponds and have been around for millions of years. When water temperature, wind and wave patterns combine with high nutrient levels in the water, these bacteria will grow into ugly mats that are most often blue-green in color, but can also be reddish-purple, or brown. The only benefit to its disgusting appearance and smell is that it tends to keep people away.
The lakes are always in motionthe wind and waves that bring a bloom to a beach are just as capable of blowing it away. Blooms can linger for mere hours or days depending on weather conditions, and the public is encouraged to pay attention to changing conditions while enjoying the water and beaches.
The appearance of these blooms is hard to predict and even harder to manage. For example, if we try using herbicides or algaecides, we will succeed in killing the bloom, but as the bacteria die, they will release all their toxins into the water and thus create a potentially bigger problem.
City of Madison engineering has installed special deflectors to help keep blue green algae out of the swimming areas of Olin and BB Clark Beaches. Public Health is in the process of evaluating the effectiveness of this approach with the hope that it might offer some protection. An innovative water treatment system will be installed shortly on Bernie's Beach. Preliminary testing of the system shows it to be very promising.
Reducing the amount of phosphorous and nitrogen fertilizers that run off into the lakes could have the effect of reducing the high concentrations of nutrients that promote algae growth. This issue is actively being addressed by a number of interested individuals and groups, but it is a long-term strategy and will not solve the immediate problem.
Public Health-Madison and Dane County monitors water quality at most Madison area beaches including routine, weekly testing for bacteria and blue-green algae. If test results show that beach conditions are not safe, the beach is closed. Follow-up testing is done every day until the problem clears up.
Up-to-date beach conditions are always available online at www.publichealthmdc.com/beaches.
For more detailed information on blue-green algae, check out the DNR's website at http://dnr.wi.gov/lakes/bluegreenalgae/
- Jeff Golden(608) 243-0302