Tag Archives: harmful algal blooms

Floating Treatment Wetlands at Rockland Lake State Park

You may have noticed something new in the water at Rockland Lake State Park.  These are floating treatment wetlands!  Read our post below to find out more about these water treatment platforms.

Why are they here? 
In recent years, harmful algal blooms have become common in Rockland Lake. These algae blooms are largely caused by an unhealthy increase in nutrients such as phosphorous in the lake.  The nutrients come from many sources nearby, including excess lawn/garden fertilizers that wash into storm ditches after a rainfall, then drain into Rockland Lake.  One culvert (inlet) with consistently high nutrient levels is located near Parking Field 5 and it was chosen as the location for a new floating treatment wetland.  The goal of adding a floating wetland to the lake is to reduce the amount of nutrients – and by extension, harmful algal blooms – in the lake.

What are they?
Floating treatment wetlands (a.k.a. floating wetlands/islands) help to bring the benefits of natural wetlands to polluted water. They filter water to improve water quality and they provide important habitat for a variety of plants and animals. Floating wetlands can come in different shapes and sizes, but in general, wetland plants are supported atop a buoyant platform, with roots exposed in the lake water below.

What do they do?
Floating treatment wetlands help to create the right balance of submerged and non-submerged wetland habitat based on each individual site’s needs. As the plants grow, they use-up excess nutrients in the water. In addition, communities of beneficial bacteria form a film around the roots, further helping to filter nutrients and pollutants. Higher/lower elevations create areas with varying oxygen levels, promoting these different biological filtering methods. The floating platform blocks sunlight, preventing the growth of algae. Lastly, fish and wildlife enjoy the new addition to their habitat.

This is the first time that floating treatment wetlands have been used in New York State Parks.  Environmental staff will determine the effectiveness of this project by monitoring water quality changes over time (e.g. harmful nutrient levels and algal blooms by the inlet as well as lake-wide).  If successful, then floating wetlands may be used to help treat stormwater pollution and improve other aquatic habitats in New York.

Post by April Brun, Gabriella Cebada Mora, and Erin Lennon.

Rockland photos by Gabriella Cebada Mora, Aissa Feldmann, Matt Brincka, and Erin Lennon.

Resources

Floating Island/Wetland images and information

US Environmental Protection Agency information on nutrient pollution and harmful algal blooms:
(Website)                   (Video)

NYS Dept. of Environmental Conservation information on fertilizers and how to reduce nutrient runoff:

(Website)                   (Video)

Harmful Algal Blooms: Keep you and your pets safe: Know it, avoid it, report it!

A group of tiny bacteria has been making a splash in New York State waters, and not in a good way. Harmful Algal Blooms (HABs, also known as cyanobacteria, Blue-green algae, BGA) are actually a type of bacteria rather than algae. If the right conditions are met, the bacteria can form what are called “blooms”, or massive amounts of floating material on the surface of a lake or pond. These blooms can look like brightly colored paint, oil, or scum, on the surface and at the shoreline of lakes and ponds. The blooms can move around a lake with wind action, or currents, and can appear, and even disappear, in a matter of hours.  Harmful algal blooms have been spotted at an increasing rate around the US in the last several years, including within some New York State Parks’ waterbodies.

The worst part about these colorful phenomena are that some species of HABs are known to produce toxins that are harmful to both humans and animals. Humans can be affected through swallowing water while swimming, touching blooms, and wading in blooms.  If the HABs are producing toxins, some swimmers can experience a range of symptoms, from simple rashes, to stomach issues, and even to muscular paralysis.  New York State Park bathing beaches are closed when a HAB is present. NYS Parks follows NYS Department of Health criteria when reopening the beach, which requires that the HAB bloom be visibly absent from the swim area for 24 hours.

Dogs are also particularly susceptible to these toxins and should not be allowed, under any circumstance, to drink or swim in a bloom.  Dog owners are encouraged to educate themselves on identifying HABs, to protect their fur-kids from harm.  Dogs exposed to HAB toxins can experience severe illness and in some cases, fatal effects.

NYS Parks posts HAB alert signs near waterbodies where HABs have been seen.

HAB Sign
State Parks HABs alert sign. If you see this sign up, do not swim in the water!

One of the best ways to recognize HABs on a lake surface is to be aware of changes to the surface of the lake. Take a look at the pictures below of HAB blooms that have been seen in NYS Parks.

HAB Paddle
HABs can look like paint, oil or foam. HABs can also coat objects as a film, photos by Karen Terbush, State Parks
HAB Green
HABs can occur around docks and have debris caught within them., photos by Karen Terbush, State Parks
Blue HAB
HABs are not always green, and can appear as smaller clumps on the surface, suspended in the water column, or sitting on the bottom. HABs can appear foamy, coat the entire surface of a lake or move around in a smaller area, photos by Karen Terbush, State Parks                                                     
HAB Dense
HAB Bloom, photo by Karen Terbush, State Parks

Be on the lookout for HABS in stagnant or still, nutrient-rich waters, when the temperatures start to rise. HABs are influenced by time of year, climate and nutrient loads.  The best way to prevent HAB growth is through watershed management. Reduce your own runoff by following NYS fertilizer guides, and help to report any evidence of HABs to the New York State Dept. of Environmental Conservation HAB hotline.

There are some HAB look-a-likes out there. Duckweed, other algae such as Cladophora (a form of clumpy, stringy algae), and pollen can easily be mistaken for HABs, especially in the spring.

Pollen Duckweed

Post by Keleigh Reynolds, State Parks

Cover image from freeimages.com.

Visit the links below to learn more about HABs!

NYS Department of Environmental Conservation: Harmful Algal Blooms

NYS Department of Health: Blue-green Algae and Health

Environmental Protection Agency: CyanoHABS