HAGERSTOWN, Md. (WDVM) — As the weather gets warmer, so does the water temperature and the Potomac River is now seeing an increase in algae blooms as they do every year.

Algae blooms are not uncommon in the Potomac River but they can be a little alarming if you don’t know what exactly they are. Luckily, the blooms that return every year, called filamentous green algae, are not harmful to humans.

The Interstate Commission on the Potomac River Basin studies these blooms and much more. The algae found in the Potomac is the result of slow-flowing waters that prevents the breaking of the delicate plant. Mike Selckmann, an aquatic ecologist with the ICPRB, also stated that algae blooms can be traced back to human nitrification. Nitrification is the microbial process by which reduced nitrogen compounds are sequentially oxidized to nitrite and nitrate.

Nitrogen is critical to plants to build proteins in their cells and is also a type of fertilizer. Algae blooms can be a result of poor agricultural practices as overuse of soil strips it of naturally occurring nitrogen. Therefore, nitrogen must be added back to the soil through compost based and chemical based fertilizers.

Algae blooms can occur when this excess nitrogen is washed out of the fields and into water sources where it gets broken down by bacteria and eventually creates atmospheric nitrogen. This excess of nutrients caused by increasing nitrite and nitrate levels, reducing alkalinity, pH, dissolved oxygen, and chloramine residuals, and promoting bacterial regrowth. The algae which survived in the water with limited nitrite and nitrate levels algae will now grow excessively because of the increased levels.

“Every state is seeing these algae blooms as kind of a novel problem. But they’ve actually been there for a very long time. They’re ancient plants. Just because there’s algae there doesn’t mean that there’s a bloom. It just means you should be cautious of it.”

Mike Selckmann, aquatic ecologist with the Interstate Commission on the Potomac River Basin

Selckmann emphasized that not all algae blooms are harmful but to avoid water that looks like paint has been spilled there. He also urged residents to check their state’s harmful algae bloom response plan as the Potomac River runs through Maryland, Virginia, West Virginia, and Washington D.C.