Identifying, Understanding and Addressing Harmful Algae Blooms

Harmful Algae Blooms (HABs) were in the spotlight this summer due to the severe impacts they had on lakes throughout the country. The nation-wide HABs outbreak caused beach closures, restricted access to lake usage, and wide-ranging health advisories.

What exactly are HABs? Why were they so severe this summer? Will this trend continue? Can anything be done to prevent the occurrence or mitigate the impacts?

In this blog, we provide answers to all of those questions, exploring what HABs are, why they occur, why they were particularly prevalent this summer, and what we can do to combat them.

What are HABs?

Simply put, HABs are rapid, large overgrowths of cyanobacteria. Cyanobacteria, also known as blue-green algae, aren’t actually algae, they are prokaryotes, single-celled aquatic organisms that are closely related to bacteria and can photosynthesize like algae. These microorganisms are a natural part of aquatic ecosystems, but, under the right conditions (primarily heavy rains, followed by hot, sunny days), these organisms can rapidly increase to form cyanobacteria blooms, also known as HABs.

HABs can cause significant water quality issues in lakes and ponds, often forming a visible and sometimes odorous scum on the surface of the water. They can produce toxins that are incredibly harmful (even deadly) to humans, animals, and aquatic organisms. HABs also negatively impact economic health, especially for communities dependent on the income of jobs and tourism generated through their local lakes and waterways.

What causes HABs?

HABs are caused by a complex set of conditions, and many questions remain about exactly why they occur and how to predict their timing, duration, and toxicity. Primarily, HABs are caused by warmer temperatures and stormwater run-off pollutants, including fertilizers with phosphates.

HABs are induced by an overabundance of nutrients in the water. The two most common nutrients are fixed nitrogen (nitrates and ammonia) and phosphorus. Discharges from wastewater treatment plants, runoff from agricultural operations, excessive fertilizer use in urban/suburban areas, and stormwater runoff can carry nitrogen and phosphorus into waterways and promote the growth of cyanobacteria.

Climate change is also a factor in HAB outbreaks, which typically occur when there are heavy rains followed by high temperatures and sunshine. Climate change is leading to more frequent, more intense rainstorms that drive run-off pollutants into waterways, coupled with more hot days to warm the water. These are the ideal conditions for HABs, which in recent years have appeared in more places, earlier in the summer.

With climate change and increasing nutrient pollution causing HABs to occur more often and in locations not previously affected, it’s important for us to learn as much as we can about HABs so that we can reduce their harmful effects.

What Can I Do to Prevent HABs?

The number one thing individuals can do to protect their waterbodies and prevent HABs is to reduce phosphorous use and reduce nutrient loads to waters.

According to Dr. Fred Lubnow of Princeton Hydro, “Managing loads of phosphorous in watersheds is even more important as the East Coast becomes increasingly warmer and wetter thanks to climate change. Climate change will likely need to be dealt with on a national and international scale. But local communities, groups, and individuals can have a real impact in reducing phosphorous levels in local waters.”

Here are a few steps you can take to improve water quality in your community lakes:

• Reduce the amount of fertilizer you use on your lawn.
• Use only phosphorus-free fertilizer when possible.
• Fix leaking septic systems.
• Use only phosphorus-free detergents in dishwashers.
• Keep yard debris such as leaves or grass clippings from washing into storm drains.
• Pick up pet waste.

Controlling stormwater runoff is another critical factor in improving water quality and reducing HABs. There are a number of low-cost green infrastructure techniques that can be implemented on an individual and community-wide scale. Click here to read more about green infrastructure stormwater management techniques.

In a recent Op/Ed published on NJ.com, Princeton Hydro President Geoff Goll lists four things that residents, businesses, and local governments should do to prevent another HABs outbreak next summer:

1. Improve aging “gray” infrastructure
2. Invest in “green” stormwater infrastructure
3. Implement regional/watershed-based planning
4. Pass the Water Quality Protection and Jobs Creation Act

“By making the necessary investments, we can simultaneously create jobs, reduce flood impacts, improve fisheries, maintain or increase lakefront property values, improve water quality and preserve our water-based tourism. The time to act is literally now,” said Geoff. Go here, to read the full article.

HABs Management in Action through Floating Wetland Islands

Nitrogen and phosphorus are utilized by plants, which means they uptake these nutrients to sustain growth. We see this naturally occurring in wetland ecosystems where wetlands act as a natural water filtration system and can actually thrive from nutrients flowing in from external sources.

This process is replicated in floating wetland islands (FWIs), where you typically have a constructed floating mat with vegetation planted directly into the material. The plants then grow on the island, rooting through the floating mat.

Not only do FWIs assimilate and remove excess nitrogen and phosphorus out of the water, they also provide habitat for fish and other aquatic organisms; help mitigate wave and wind erosion impacts; provide an aesthetic element; and can be part of a holistic lake/pond management strategy. Because of this, FWIs are being utilized to improve water quality and control HABs in lakes and ponds throughout the country. Princeton Hydro has designed and implemented numerous FWIs in waterbodies large and small. Go here to learn how they’re being used in Harveys Lake.

Recognizing and monitoring the changes that are taking place in our local waterways brings the problems of climate change, stormwater pollution and the resulting water quality issues closer to home, which can help raise awareness, inspire environmentally-minded action and promote positive, noticeable change.

If you spot what you believe to be HABs in your community lake, contact your local lake association right away. They, along with their lake management team, can assess the situation and determine what further actions need to be taken.

For more information about HABs, click here.

Special thanks to Princeton Hydro Staff Scientist Ivy Babson for her contributions to this blog.

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• Climate Change
• Environmental Education
• Environmental Services
• Lake and Pond Management
• Stormwater Management
• Uncategorized