What is blue-green algae and can it hurt you or your dog?
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.
Should you be afraid? Here are answers to some basic questions about the bacteria and its risks.
Q What is blue-green algae?
A
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 temperatures, 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. 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?
A 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.
(Philadelphia Inquirer/Tribune News)