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Harmful Algal Blooms May Impact Your Water

HABs in our lakes and drinking water reservoirs are a danger to humans, pets and wildlife, says aquatic ecologist Meiyin Wu

Posted in: Faculty Voices, Homepage News, Science and Technology

Meiyin Wu working on equipment in a lab.

Summer’s around the corner and so are reports of harmful algal blooms (HABs) in our lakes and ponds.

But did you know HABs also pose a threat to our drinking water?

Meiyin Wu, director of the New Jersey Center for Water Science and Technology (the only state-certified testing lab for cyanotoxins in New Jersey) and professor of biology, explains how HABs in our lakes and drinking water reservoirs are a danger to humans, pets and wildlife – and how we can test water for them.

Cause of harmful algal blooms

According to the United States Environmental Protection Agency, “certain environmental conditions in water bodies can intensify algae growth, causing algal blooms. Blooms with the potential to harm human health or aquatic ecosystems are referred to as harmful algal blooms or HABs.” One major culprit behind HABs? Climate change, Wu says.

“Extreme weather such as tropical storms, can cause erosions and runoffs,” Wu says. Cyanobacteria feed on the abundance of nutrients from the runoff, allowing them to thrive, and higher temperatures are likely to boost their growth. “It makes the water warmer, and warmer water temperatures makes cyanobacteria grow faster and gives them a competitive advantage over other phytoplankton species.”

That green scum you’ve probably seen on lakes or ponds (in person or in the news) is not the only sign of HABs, Wu says. “When seeing the green scum, it’s really bad. A HAB event can only be confirmed under a microscope or with molecular techniques. Cyanobacteria are suspended in the water, and it’s often invisible to the naked eye. That’s why it’s such a threat to humans, pets and wildlife because if you can’t see it, you’ll never know it’s there.”

Impact of HABs on humans and wildlife

Humans who have short- or long-term exposure to HABs, via direct contact, ingestion or exposure to water vapors, might exhibit symptoms and a long list of illnesses associated with exposure to cyanotoxins including hay fever-like symptoms, respiratory and gastrointestinal distress, and even liver and kidney damage, per the EPA. Most at risk are people who live around the water and use it all the time, Wu says, such as residents of lake communities and anglers. It is not recommended to drink water or consume fish/crabs caught from HAB infested waters.

“Please also keep your pets away from HAB infested waters,” Wu says. Dogs that spend time in water where there are HABs can directly ingest water, carry cyanobacteria and cyanotoxins on their wet fur, and lick it off; dogs have been reported to die within hours of this occurring. As far as other animals and wildlife, there is insufficient data to fully understand its health effects, Wu says. “There are many cyanotoxins that have not been fully documented and could potentially have effects on humans and wildlife and we just don’t know yet.”

How do HABs affect drinking water?

When the HAB monitoring program first launched in New Jersey, Wu says, the focus was limited to major recreational lakes like Lake Hopatcong and Greenwood Lake. But the impact of HABs is not limited to recreational waters. It also affects the sources of our drinking water: reservoirs, lakes, rivers and groundwater from where a water treatment plant draws water.

In New Jersey, lake and river waters are used as source water for drinking water, and HABs can also be present in those source waters. Ideally, cyanobacteria and cyanotoxins should be removed during the water treatment process before it gets to our homes; however, the treatment might not always be effective. The additional treatment process to remove cyanobacteria and cyanotoxins can also increase the cost of treatment; consequently, HABs can potentially cause our water bill to go up. (TIP: Cyanobacteria are known to produce taste and odor compounds, Wu says, so if your water appears to have an odor or taste, it could be due to HABs.)

If HABs are out of control, this may put public water supply at risk of losing its source water; on the other hand, the extensive water treatment required to remove HABs has led to significantly increased expenditures for drinking water treatment. Some states, like New York and Ohio, Wu says, are very proactive in doing HAB testing and routine monitoring of its lakes and source waters for drinking water supply. In other states, including New Jersey, there’s a shortage of testing. “We have a long way to go as a state to catch up on this front.”

Testing source water for HABs

The best way to find out if your source water is safe is to actually test it, Wu says, and added that anyone is welcome to visit the University’s certified lab to do just that.

If you suspect that an area lake or pond has HABs, Wu says, contact the NJDEP (or your state’s department of environmental protection), file a report online or call and request the water to be tested. Unfortunately, Wu says, by the time a bloom has been noticed and reported, it has often already progressed to a potentially dangerous situation.

“The most effective HAB management is to employ proactive routine monitoring, which would allow potential HABs to be identified as quickly as scientifically possible, enabling rapid response measures to be taken while the populations of cyanobacteria in the water is still relatively low. Managing HABs will therefore become more efficient, streamlined, and feasible.”

To speak with Meiyin Wu, please contact Montclair State University Media Relations.