Mecklenburg County residents have been warned to steer clear of ponds at Charlotte parks after tests revealed toxic algae at a pond in Park Road Park in south Charlotte. In Wilmington, three dogs died after exposure to toxic algae there.
As for Chatham County? It’s rich with natural and man-made ponds and lakes, which means residents should be aware of the potential for toxic algae.
The typical season for algal blooms is between April and October. According to Sarah Young, public information officer for the Department of Water Resources at N.C. DEQ, algal blooms are most common during summer months when bright sunlight, warm temperatures and increased nutrient availability in waterbodies provide conditions that promote algal growth.
According to N.C. DEQ, Cyanobacteria, commonly called bluegreen algae, are naturally occurring bacteria present in most fresh waterbodies across North Carolina. When conditions are right, such as an “extended photoperiod during summer, sufficient nutrients, and slow moving or stagnant waters” the algae can form a bloom, some of which produce toxins called cyanotoxins. These toxins can cause illness in humans and can be deadly to animals when in contact with a bloom.
Toxic blooms can also cause fish kills. According to the N.C. Dept. of Health and Human Services, toxic blooms can “affect the kidneys, gastrointestinal tract, liver, and nervous system of people, pets, livestock and other animals.” This is especially true for children and dogs, but NCDHHS notes that there have been “no reports of adverse health effects in children associated with cyanobacterial blooms have been identified in North Carolina.”
Though there have been numbers of media reports on algae blooms in North Carolina, Young is hesitant to say this year is different from any other.
“Because our algal bloom response is dependent on citizen reports of bloom occurrence, we cannot say definitively that this year is any different from previous years,” Young said. “Cyanobacterial (bluegreen) algal blooms are not a new phenomenon in North Carolina, but as public awareness of blooms increases, the number of reports we receive increases. However, research indicates that cyanobacterial bloom occurrence is increasing globally as a result of rising temperatures associated with climate change.”
Young notes that the “swimming areas around Jordan lake are not routinely monitored for the presence of algal blooms” as testing by N.C. DEQ is “conducted in response to citizen reports of algal bloom activity.”
“We have received no algal bloom complaints from Jordan Lake this year,” Young said.
According to Park Superintendent Shederick Mole, Jordan Lake’s recreations beaches have not been closed for algae blooms in the eleven years he has worked at Jordan Lake State Park.
According to Young, algae comes in many types that are able to form blooms creating a wide variety of possible characteristics. N.C. DEQ has a Cyanobacterial Bloom Identification Guide on its website to assist residents.
“The characteristics of a bloom can change over time,” Young said. “For example, many cyanobacterial blooms will turn from green/bluegreen to milky blue/white when they begin to decay, but the range of descriptions tends to be caused by different types of blooms and not the different stages of a bloom.”
“Cyanobacterial blooms may or may not be easily visible,” N.C. DEQ’s website notes. “Blooms can form below the water’s surface or along the bottom. Cyanobacterial blooms that form near the water’s surface can cause water discoloration, surface scums (often described as “spilled paint”), or floating clumps or mats. Blooms can appear bright green, blue, red, or brown. As cyanobacteria in a bloom begin to die, they may produce a strong, foul odor and turn milky blue in color.”
NCDHHS notes that if residents see an algae bloom, they should keep themselves, their pets and their livestock out of the water. It also notes that there is no way to tell if a bloom is toxic just by looking at it so it is best to steer clear. If a resident notices a bloom after they or their pets entire a lake or pond, it’s important to rinse off immediately with tap water and prevent pets from licking their fur.
Though testing for toxic algae requires a specialized laboratory, there are home test kits available through private vendors. Even if a waterbody tests positive for a cyanobacterial bloom, there are no effective means of treating it once it appears.
“Treatment with algacides is not recommended as these compounds can cause the cyanobacteria to rupture releasing any toxins contained within the cells,” Young said.
If you suspect an algae bloom, N.C. DEQ suggests reporting it either through the Fish Kill/Algal Bloom Reporting form or by contacting the nearest Regional Office.
Reporter Casey Mann can be reached at CaseyMann@Chathamnr.com.