The lowdown on blue-green algae
Blue-green algae, a yearly occurrence at some lakes and ponds, has emerged as a growing scourge this summer after an outbreak forced New Jersey to shut down beaches at its largest freshwater lake.
On top of that, four dogs died this month in North Carolina after swimming in the pond loaded with it.
Here are answers to some basic questions about the bacteria and its risks.
Q: What is blue-green algae?
Blue-green algae is the common name for a type of cyanobacteria, though these bacteria aren’t truly a form of algae. Cyanobacteria can produce toxins harmful to people, pets and livestock. They mostly grow in freshwater lakes and streams, but they are found in marine waters, such as estuaries. When blue-green algae grow excessively, it’s called a bloom. Usually the trigger is a combination of sunlight, warm conditions and nutrients, generally from lawn and farm fertilizers.
The blooms appear as a thick coating on the water, usually in late summer or early fall, and are either bluish-green or resembling white paint. They can emit an unpleasant odor.
But not all blooms are cyanobacteria. Some are common green algae — which are not toxic.
After testing in June, the New Jersey Department of Environmental Protection confirmed that a mat of algae on Lake Hopatcong in Sussex County fit the definition of a Harmful Algal Bloom, or HAB. Beaches at the state’s largest lake were closed. Just this week, the DEP lifted an advisory against swimming in the lake. In all, the state has confirmed 16 locations this summer where harmful algae blooms were present, all in central or northern New Jersey.
Harmful blooms haven’t been reported in Southeastern Pennsylvania swimming beaches this summer, though the U.S. Army Corps of Engineers did issue an advisory for popular Blue Marsh Lake in Berks County a few weeks ago when algae blooms were found. Stephen Rochette, an Army Corps spokesman, said the blooms never rose to levels that posed a concern for toxins.
Q: How can I keep my pets safe?
First, regardless of whether algae is present, many waterways are already “impaired” in the Philadelphia region, meaning they have some degree of pollution. The waterway might get flows of road runoff containing gas and oil, and stormwater runoff that contains chemicals and untreated sewage. Drinking the water, which can contain high levels of fecal and other bacteria, can make people — and pets — sick.
If you wouldn’t swim in it, it’s a good bet it’s not good for your dog.
According to the EPA, you should not let your dog drink or swim in water if it looks slimy, or if there is foam or scum on the surface. If the color is weird, that’s another indicator something is wrong.
Cyanobacteria can vary in color. Aside from the familiar blue-green, harmful blooms may be blue, bright green, brown or red. They may resemble paint floating on the surface.
A strong, even nauseating odor is another indicator. If the water stinks, it’s probably not safe.
Q: What can happen to me if I’m exposed to it?
The toxins in harmful algae blooms can sicken people who drink the water or accidentally swallow it while swimming, boating or fishing, or even simply swim in it.
Some of the symptoms are rashes, stomach or liver illness, respiratory issues or neurological problems.
If you swallow water from a location that may have a harmful algae bloom, call your doctor or a poison center.
Q: What if I think my dog or pet has been exposed?
Symptoms of a toxic effect might not be immediately apparent and can take days to appear. Some of the symptoms include diarrhea, vomiting, weakness, staggering, drooling, difficulty breathing or convulsions.
If you think your dog has been swimming in a pond or lake with cyanobacteria, rinse the pooch immediately with clean, fresh water. You should wear protective gloves while bathing your dog.
Take the dog to the vet immediately if you see any symptoms arise.
Q: What if I spot or suspect a harmful algae bloom?
It’s best to report it to your state environmental agency.
Q: If blue-green algae isn’t new, why am I hearing so much about it now?
It appears to be proliferating. The Environmental Working Group examined filings by the EPA in its National Lakes Assessment, conducted every five years. EWG also looked at data filed by 14 states that monitor for microcystin, a class of toxins produced by bluegreen algae.
In both 2007 and 2012, the most recent data available from the EPA, testing found microcystin in water bodies in all contiguous 48 states. But the EPA showed that there was a near 10% increase in that period. The 2017 survey results are not yet public.
Q: Is climate change a factor?
The conditions that mark climate change also can promote blue-green algae. EWG says recent outbreaks of bluegreen algae are starting earlier in the year and lasting longer.
The group cites increasing rainfall and rising temperatures as contributing to the growth of blooms. More rainfall means more pollution and runoff end up in streams, lakes, creeks and rivers.
The New Jersey Conservation Foundation said increased storm runoff could be fueling some of the nutrients cyanobacteria need to flourish. Municipal storm systems can’t handle the additional water so the systems overflow, allowing runoff to go directly into streams and waterways.
The foundation said residents can help by not using chemical fertilizers on lawns and gardens, maintaining their septic systems, planting native trees or shrubs around waterway edges to filter out contaminants, building rain gardens, installing rain barrels and properly disposing of pet waste. Leaving the poop to be washed away by the next rain means it goes into the nearest waterway.
Q: Isn’t blue-green algae sold as a diet supplement?
Yes, but it’s not the same as what’s plaguing waterways.