By Maeve Dunigan
Last year the most profound bloom of toxic algae in 100 years took over Lake Erie, which is bounded by both Canada and the U.S. This year, the blooms proved less prevalent, but the overbearing green organisms still worry those who rely on this important water supply.
According to EcoWatch, Lake Erie is a water source for about 11 million people. During a scare in 2014, algae closed the drinking water treatment plant in Toledo, Ohio for a period of time due to a high level of algal cyanotoxins found in the water.
These blooms could be attributed to a variety of causes, but researchers remain unsure as to how such factors can be combined to create a bloom.
The National Oceanic and Atmospheric Administration (NOAA) website states that the blooms “may be linked to 'overfeeding.'” This process occurs when nutrients including phosphorus, nitrogen and carbon, which are used in fertilizer on lawns and farmlands, “flow downriver to the sea and build up at a rate that 'overfeeds' the algae that exist normally in the environment.”
NOAA contends that the blooms are to blame for “about $82 million in economic losses to the seafood, restaurant and tourism industries each year.”
The less severe bloom this year is thanks to a more normal rainfall. The less it rains, the less runoff is pushed off of the farms and other harmful sites and into tributaries that feed into the lake.
The problematic algae in Lake Erie can be found in many bodies of water throughout the U.S., even those close to Maryland and the eastern shore.
“The same species [of algae found in Lake Erie] is in the Chesapeake Bay,” said Christopher Brown, a researcher at NOAA.
Brown spoke about varieties of cyanobacteria, or bacteria that obtain energy through photosynthesis, which exist in different bodies of water. Many of these species of bacteria can be identified floating on top of the water in dark green sheets.
“Some [bacteria] have air vacuoles that allow them to float,” he said. “That’s why you get this surface scum when there’s low wind they tend to accumulate.”
It’s very difficult for water municipalities to filter these surface toxins from the drinking water. Not only that, wildlife, especially domesticated animals like cattle and dogs, can get sick or die from imbibing the water.
Brown said that the toxins in the algae are a sort of defense mechanism, to ensure they aren’t fed upon by fish and other organisms.
The U.S. Environmental Protection Agency (EPA) recommends management practices for the harmful phosphorus and nitrogen nutrients. The EPA also says that increasing the water flow through bodies of water, although expensive, is a good way to avoid large cyanobacteria blooms.
