Dangerous Algae Blooms Taking Over Waterways Nationwide
Algae doesn’t seem that bad– some are even edible (and healthy) or decorative! But when large-scale algae growth (known as an algae bloom) takes over lakes, rivers, oceans and other bodies of water, it can bring trouble to marine life and to anyone that comes in contact with the bloom.
The following article is excerpted from National Environmental Education & Training Foundation (NEEF), and includes tons of helpful information about why algae blooms happen, the dangers of algae blooms, and resources for more information about algal blooms.
What are Algae Blooms (Algal Blooms)?
Algal blooms impact water quality and have the potential to produce toxins that can harm humans, pets, and wildlife. The blooms are caused by a combination of factors that promote high densities and reproduction of algae: high concentrations of nutrients that feed algae, like nitrogen and phosphorus, warm temperatures, sunlight, and shallow, slow-flowing water.
Algal blooms come in many colors and can have serious negative health impacts on humans and animals by contaminating waterways and drinking supplies.
A type of algae called blue-green algae, or cyanobacteria, is the predominant culprit behind toxic algal blooms in freshwater systems. These bacteria produce cyanotoxins that can impact the liver, the nervous system, and the skin of those who are unfortunate enough to come into contact with them.
Drinking, bathing, or swimming in contaminated waters can lead to an array of negative health impacts including blisters, fever, muscle and joint pain, paralysis, asthma, and allergic reactions such as rashes. In extreme cases, the deaths of wildlife and domestic animals have been reported in association with toxic algal blooms.
If you see a body of water with surface discoloration such as a red, green, or brown tint, especially if the water has a thick, mat-like accumulation of scum on the shoreline and surface coupled with an unpleasant smell, remember this tips to stay safe from algae blooms:
- Stay away from it. Do not use the water for swimming, boating, or fishing. Keep children and pets away as well.
- If you accidentally come into contact with water you suspect is contaminated, immediately rinse off with clean, fresh water.
- Do not attempt to kill the algae with algaecides yourself—by killing the algae, the cells are burst, which can release the toxins into the water. Allow professionals to determine if a chemical treatment is necessary.
- If you think someone has been poisoned by a toxic algal bloom, seek medical attention immediately.
- Report algal blooms to your state’s department of health or environment. Find your state’s contact information.
- Protect your family and pets by learning more about the health effects of harmful algal blooms and how to protect yourself.
What Causes Algae Blooms?
A changing climate could favor the global expansion of cyanobacteria (blue-green algae) through predicted changes in temperature and precipitation.
- Warmer temperatures increase the growth rate of cyanobacteria. Toxin producing cyanobacteria, such as Microcystis, grow faster in higher temperatures than other non-harmful algae. Milder winters and warmer springs also lengthen the algae growing season.
- Warmer temperatures increase thermal stratification in water. Differences in temperature and density create layers in the water column – warm water at the surface has lower density than deep, colder water. The warming of surface water accentuates this stratification and can limit the wind’s ability to mix the water, reducing the movement of oxygen and nutrients throughout the water column. This favors the growth of cyanobacteria in the warm surface layer, where they can feed on nutrients and block sunlight from other algae and aquatic life.
- Larger and more intense precipitation events can fuel algal blooms by increasing the transport of nutrients into waterways via stormwater runoff.
- Severe and more frequent droughts combined with evaporation from warmer air temperatures reduce water levels, increasing salinity. High salinity can cause salt stress in cyanobacteria, leading to leakage of cells and the release of toxins into the water. Increased saltiness can also create conditions that allow marine algae to invade freshwater ecosystems.
Scientists have discovered that in warmer temperatures cyanobacteria can produce harmful algal blooms with lower concentrations of the nutrients they feed upon. Scientists have also reported the expansion of cyanobacteria into lakes that have not had an increase in nutrients, indicating that temperature can promote the geographic expansion of some species of cyanobacteria.
Watch this helpful video below to make sure you know algae safety for the whole family: