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.
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.
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.
If you frequent nature trails, you have likely passed by stones or trees with some kind of crusty material on the surface. Is it a moss? No, moss is a plant. Is it a fungus? Well, yes and no. This crust is actually a partnership between at least two different organisms, making a composite organism called lichen (pronounced “LIKE-en”).
Lichens are made of multiple fungi – a diverse group of organisms including mushrooms, molds, yeasts, and others – living with algae and/or algae-like bacteria called cyanobacteria. The fungi provide a pleasant, hydrated shelter to live in, while their partner provides food through photosynthesis. Photosynthesis means using sunlight, water, and CO2 to create sugar (and the oxygen that we breathe, no big deal). Cyanobacteria can also “fix” or make use of nutrients from the air, further helping the fungi to grow. This mutual relationship between different species is what biologists call symbiosis.
Thanks to the many possible fungi-algae-bacteria combinations, lichens take on many different forms and colors. In New York State alone, there are over 800 types of lichens! Lichens can look like small flaky crusts (“crustose”), flat leaf-like growths (“foliose”), or even branched (“fruticose”) like miniature shrubs. Many take on a greenish-grey hue, but other colors include brown, black, white, yellow, bright orange, red, and blue. You might see these unique fungal partnerships on all kinds of surfaces along nature trails – adding a nice flair to wooden sign posts, historic stone walls, boulders, tree bark, the forest floor, and decaying logs.
People have used lichens for a variety of purposes for thousands of years. Lichens with antibiotic properties have been used in traditional medicines and embalming practices. Some of the more brilliant-colored lichens have been used to make dyes for yarn, cloth, and even litmus paper (a quick, easy way to measure how acidic something is). Several cultures worldwide include lichens in their diets, making soups, side dishes, beverages, and even molasses. But watch out – not all lichens are safe to eat! Those involving cyanobacteria can produce toxins; these lichens have historically been used as poisons in hunting.
While all these uses of lichens are interesting, we at New York State Parks want you to simply enjoy observing the beauty and impact of lichens in their natural habitats.
Lichens in Nature
Lichens serve several important roles in our parks. As one of the first lifeforms that established on land, they helped create much of the world we live in today. They play a role in soil formation, slowly breaking large rocks down into smaller pieces. Then they carry out processes that add essential nutrition to forest soils, allowing trees and plants to grow. Lichens also benefit wildlife. Northern flying squirrels, deer, and moose are among those known to graze on lichens, particularly in the winter. In the spring, birds like the Ruby-throated Hummingbird and the Blue-Grey Gnatcatcher often use lichen to build and camouflage their nests.
Lichen populations also give important clues about environmental health. Studies have shown lichen to be sensitive to air pollution, and so a decline in lichen may be a warning sign of worsening air quality nearby. Similarly, lichen growth rates react to long-term changes in moisture and temperature, and so they can help monitor the climate. Scientists take advantage of the slow-growing nature of certain lichens and use their size or branching patterns to estimate the age of rocks in the forests, similar to tree rings on a tree stump.
By keeping an eye on the lichens in our parks, we can discover fascinating patterns in our local ecosystems. And we can have a deeper appreciation for the beautiful landscapes that New York State has to offer!
See if you can spot these and other lichens the next time you are out enjoying nature:
Reindeer moss (Cladonia rangiferina) in the winter. Despite the name, this is actually a lichen. There are many similar species of Cladonia that can be seen in New York State Parks. (Photo by Steve Young, NYNHP)
Grey rock tripe (Umbilicaria sp.) and a finely-textured crustose lichen on a cliff community. (Photo by Gregory Edinger, NYNHP)
This spongy gray-green lichen was found in a chestnut oak forest. (Photo by Gregory Edinger, NYNHP)
Orange-brown rock tripe (Umbilicaria sp.) can be found on big rocks and outcrops at State Parks such as Minnewaska, Sterling, Moreau, and others. (Photo by Steve Young, NYNHP)
Up-close and personal with a leaf-like (“foliose”) lichen on a tree in Thacher State Park. (Photo by Erin Lennon, NYS Parks)
Stepping back to admire a mix of foliose lichens (grey and light-green), crustose lichen (small golden speckles), and moss (dark green) on the same tree trunk at Thacher State Park. (Photo by Erin Lennon, NYS Parks)
Post by Erin Lennon, State Parks
Featured image: A common sight: lichen attached to tree bark in New York State. (Photo adapted from Wikipedia, public domain)