Blue-green Algae Frequently Asked Questions Are there web sites for more information about blue-green algae? What is blue-green algae? Blue-green algae, or “cyanobacteria,” are natural to the environment’s food chain and are found all over the world. They are actually a type of bacteria but, like plants, they can use sunlight to grow. Many live with other types of algae and microscopic animals, collectively termed “plankton.” Blue-green algae are a group of organisms that are among the oldest on the planet. They are ubiquitous - found in marine waters as well as freshwater and brackish habitats. Blue-green algae are also common in other states, including Georgia, Texas, Alabama and Michigan. Some – not all – blue-green algae can produce toxins that can contribute to environmental problems and affect public health. Those blue-green algae that are known to produce toxins do not always do so. Little is known about exactly what environmental conditions trigger toxin production. Blooms can float on the surface and be several inches thick or they can lie below the surface of the water. Blooms can disappear from view or move to different parts of a pond or lake. top What causes blue-green algae blooms?

Blue-green algae multiply quickly in water bodies with high nutrient levels such as phosphorous or nitrogen, and particularly when the water is warm and the weather is calm. That's why blue-green algae are most common in Florida in the summer and early fall, with its high temperatures and abundant sunlight, although they can occur at any time. Waters that flow slowly with low turbulence – such as impounded rivers, dams, or water storages – are at particularly high risk of algal blooms. Blue-green algae growth can become seemingly explosive when lots of nutrients are present, providing a rich feast that can then cause “blooms” that may look like floating carpets of blue-green algae turning the water green. Many other states, and countries for that matter, are experiencing problems with algal blooms. top Are the blue-green algae blooms a new problem? Algal blooms are not a new phenomenon. Algal blooms were documented in Florida’s coastal waters as early as the 19th century. However, increased nutrient loading in our waterways has likely contributed to increased frequencies of blooms in our freshwater systems.

In 1998, recognizing the need to assess the status of toxic microalgae in Florida, the state legislature approved funds to the Florida Harmful Algal Bloom Task Force (FLHABTF) to address any potential concerns regarding microalgae, including blue-green algae. Collaborative studies funded by the FLHABTF were initiated between the St. Johns River Water Management District, the Florida Fish and Wildlife Conservation Commission’s Fish and Wildlife Research Institute, Florida Department of Health (DOH), private laboratories, and Wright State University to investigate the distribution of toxic blue-green algaeand their toxins (cyanotoxins) in Florida waters. For more information on this topic, please visit HAB Task Force Blue-Green Algae Studies . top How long do the blooms last? Blooms can last days, weeks or months, depending on conditions. Scientists cannot predict when or where blooms will occur or how long they will last; the blooms run their course and dissipate naturally. Can blue-green algae blooms be treated? No. The Florida Fish and Wildlife Conservation Commission does not recommend treatment because it may release the toxins.

The Bureau of Invasive Plant Management does not favor, and does not issue permits for, the application of algaecides to treat blue-green algal blooms in surface waters of the state. Such treatments are generally not very effective and would need to be repeated frequently, potentially resulting in unacceptable levels of algaecide in surface water bodies. Surface water bodies used as drinking water reservoirs may be treated on occasion by water treatment plants in some counties. These treatments are exempt from permit requirements related to the application of algaecides in surface waters of the state. top Are large blue-green algae blooms harmful to lake/river ecosystems and cause fish kills? Blooms of blue-green algae that last more than a few months can be harmful to lake/river ecosystems and cause fish kills because of the decrease in oxygen levels and direct ingestion in the food chain: Persistent blooms block sunlight that feeds plants growing on the bottom of lakes, resulting in the loss of rooted aquatic vegetation, which is valuable fish habitat. Intense blooms can cause extreme fluctuations in daytime and nighttime water oxygen levels, due to the oxygen produced during the daytime photosynthesis and the oxygen consumed during the nighttime respiration.

The nighttime respiration as well as the decay of the blue-green algae, can consume much of the oxygen in the water, causing fish to die. Algae use sunlight to make food and are eaten by microscopic animals (zooplankton). Small fish eat the zooplankton, and larger fish and other large animals eat the small fish. However, blue-green algae are often difficult to eat or are of poor nutritional value for zooplankton. Consequently, zooplankton, particularly types that are the best fish food, often decline during blooms. This decline can impact the number of desirable game fish. top What is the state doing about the blue-green algae blooms? As part of our mission and responsibilities, the state – including Florida Department of Environmental Protection, Florida Fish and Wildlife Conservation Commission, Florida Department of Health, St. Johns River Water Management District, South Florida Water Management District-and the University of Florida is responsibly concerned, not alarmed, about the current situation as we continue to monitor, evaluate and provide information to other concerned local, county, state and federal agencies. The state is looking to increase the frequency and expand some of its current routine algal bloom monitoring in the major water bodies to try and get a better understanding of the phenomenon.

This information will be shared with our government partners and the public as it becomes available. We’ve increased communication with: Media What are Harmful Algal Blooms? « Harmful Algal Blooms Effects of Harmful Algal Blooms General Information Though many types of algae can form blooms, freshwater harmful algal blooms have the ability to produce toxins that are dangerous to other organisms such as humans, dogs, and livestock. Most harmful algal blooms occur in warm, slow moving, eutrophic waters in mid June through late September and are formed by cyanobacteria (aka blue-green algae) which are now known to be photosynthetic bacteria. Algal blooms can also be caused by haptophytes, dinoflagellates, green algae, raphidophytes, euglenophytes, diatoms and cryptophytes, but though they can be a nuisance, they do not produce toxins like cyanobacteria do and have not been linked to any adverse human health effects in the United States. Photo Credit: Erika Phillips It is possible for blooms to appear quickly and form floating mats of various colors, however, not all blooms form mats on the surface. Some remain in the water column and discolor the water.

While it is estimated that most blooms are toxic, it is difficult to predict exactly when or even if a bloom is producing toxins. A bloom of a certain type of cyanobacteria may or may not produce toxins and the toxicity may change throughout the duration of the bloom. It takes a few days for blooms to be sampled and tested for toxicity, and by that time the toxicity may have changed. Furthermore, the harmful effects of blooms may even occur when a bloom is not visible. Blooms that occur in drinking water sources can produce compounds that lead to toxicity as well as taste and odor problems of the water. The majority of the time, taste and odor compounds, not toxicity, are the largest problem in terms of cyanobacterial contamination in drinking water. Toxicity can occur in drinking water even without taste and odor compounds, though. In Wisconsin, most drinking water comes from groundwater, not surface water, so drinking water problems caused by harmful algal blooms are rarely a concern. Some of the techniques that can be used to control or remove blooms, such as algaecides, can increase the toxicity of the bloom. They may also be detrimental to organisms other than cyanobacteria and are generally not recommended.

The most effective method to reduce blooms is community effort to reduce the Phosphorous loading of fresh water bodies. Though cyanobacteria are found in some of the oldest fossils and are natural to aquatic habitats, harmful algal blooms are increasing in frequency in the United States and across the world and are becoming more of a problem. (top) Cyanobacteria Cyanobacteria are prokaryotes that are usually as large as eukaryotic algae and can be either filamentous or non-filamentous. Most cyanobacteria stay near the surface of the water and have mechanisms such as gas vesicles to control their buoyancy. They can adjust buoyancy with light and nutrient levels during the day, but at night they may float to the surface, causing it to look like the bloom appeared rapidly. Also, on days when there is little mixing due to wind, the buoyant cyanobacteria can float to the surface and form blooms with high population densities because they are all on the surface instead of being spread through the water column. Because of this, when mixing is weak, cyanobacteria have the advantage over other phytoplankton. The genus cyanobacteria is very large and diverse.

They can occur in all types of water (marine, estuarine, fresh), and their critical light intensities also vary greatly. Cyanobacteria colonies are usually too large for zooplankton to eat, and they are generally not nutritious which leads to little top-down control. In addition, most also form a mucilage sheath that makes them unpalatable to organisms such as zooplankton and zebra mussels, which can help their population to grow to bloom numbers. Because blooms of one type of phytoplankton prevent other algae from growing, consumers and predators may starve during cyanobacterial blooms due to their lack of palatability. Nitrogen and Phosphorous are necessary for cyanobacterial growth, but Phosphorous is usually the limiting nutrient because they are generally poor competitors for Phosphorous in comparison to other phytoplankton. However, Planktolyngbya, Anabaena, and Aphanizomenon are strong competitors for Phosphorous in lakes that contain more organically bound Phosphorous. This is because these types of cyanobacteria produce the enzyme alkaline phosphatase that releases Phosphorous from small organic Phosphorous compounds.

The Nitrogen fixing cyanobacteria Anabaena, Nodularia, Nostoc, Gloeocapsa, Trichodesmium, and Synechococcus are most often poor Phosphorous competitors. This is why waters that are nutrient rich due to fertilizers high in Phosphorous, untreated sewage, wastewater, or agricultural runoff are more likely to experience blooms. Some cyanobacteria produce heterocysts that alow them to fix nitrogen and/or resting cells called akinetes that allow them to survive through unfavorable conditions. The WHO says that 100,000 cells/mL is a moderate human health risk, but there are currently no standards for cell or toxin concentrations in the United States. Cylindrospermopsis raciborskii is a type of cyanobacteria that isn’t native to Wisconsin but it was probably brought to the state by waterfowl. It usually blooms in late July through late September and stays in the water column. It can produce multiple toxins including Cylindrospermopsin, but that hasn’t been found in any Wisconsin lakes.

Table of Common Cyanboacteria: (some values may not apply to entire genus) Name (top) Toxins The toxins produced by cyanobacteria are the main concern during harmful algal blooms. They are produced within the cells and remain there until the cells break open, which may lead to the unpredictable toxicity of blooms. Normal water treatment processes can remove cyanobacteria and their toxins, but sometimes further steps are necessary when cell or toxin concentration is high. The extracellular toxins are also more difficult to remove than the toxins within the cells. In aquatic environments, the toxins are broken down by heterotrophic bacteria, but during times of slow mixing, the toxins can build up because the bacteria can’t get to the toxins as quickly. The World Health Organization standard for Microcystin-LR in drinking water is 1.0µg/L, but there are no standards for recreational waters in the United States. Microcystins are the most commonly occurring toxins. There are at least sixty microcystins known now and the toxicities can be vastly different. Nodularin is very similar to microcystins and has the same effects. Anatoxins are the cause of paralytic shellfish poisons are very poisonous.

Lyngbyatoxin a and aplysiatoxins are both tumor promoters, and lyngbya toxin a causes seaweed dermatitis. Cylindrospermopsis is most harmful to the liver, but it may damage other organs as well. The toxins produced by cyanobacteria can also harm other aquatic organisms. The toxins produced by Scytonema hofmanni and Fischerella muscicola can inhibit photosynthetic electron transport. Anabaena flos-aquae prodices a toxin that paralyzes the green alga Chlamydomonas, and microcystins inhibit carbon fixation in other phytoplankton.

Genus Exposure to cyanobacteria and cyanobacterial toxins can occur from: Drinking water that contains cyanobacteria Drinking untreated water Engaging in recreational activities in water experiencing a bloom Inhaling aerosolized cyanobacteria or toxins such as the spray from jet skiing and boating, and using contaminated water to water lawns or irrigate golf courses Consuming cyanobacterial supplements containing mycrocystins Dialysis (this has only occurred in Brazil) Effects of Harmful Algal Blooms Ecological Harmful algal blooms negatively impact the food web by decreasing the amount of nutritious, edible phytoplankton that zooplankton and other primary consumers need to survive. These organisms may then starve, leading to decreased food for secondary and higher order consumers. Increased cell concentration can block sunlight from primary producers under the water’s surface as well, leading to decreased food and oxygen levels. When the cells in the bloom begin to die it can also lead to decreased dissolved oxygen levels that can be lethal to other aquatic organisms and cause fish kills. Low dissolved oxygen can be made worse by overcast days and warmer temperatures.

Human/Animal Decreased recreational use and aesthetical value of waters due to toxicity, mats of algae, and the smell when cells begin to die are only some of the problems associated with harmful algal blooms. Cyanobacterial blooms can contaminate drinking water with taste, odor, or toxic compounds. The toxins produced during blooms are possible carcinogens to humans and current research is studying the link between certain cyanobacterial toxins and neurological disease. Harmful algal blooms have been known to kill waterfowl and livestock, and dogs have died after eating mats of cyanobacteria or licking their fur after swimming in bloom infested waters. In some cases, humans have also died after exposure to harmful algal blooms. * General for marine phytoplankton – **General for cyanobacteria – a – b – Komárek J. & Hauer T. (2010): CyanoDB.cz – On-line database of cyanobacterial genera. – Word-wide electronic publication, Univ. of South Bohemia & Inst. of Botany AS CR, c – Information about why algae grow in lakes General Algae Information What are algae?

Algae are primitive, primarily aquatic, one-celled or multicellular plant-like organisms that lack true stems, roots, and leaves but usually contain chlorophyll. There are both marine and freshwater algae, and algae are found almost everywhere on earth. The Washington Department of Ecology's algae program focuses on algae problems in freshwater. Pond scum is algae (mostly), the green slime on rocks in a stream is also algae, as is the pea soup green seen in some nutrient-enriched lakes. Why do algae grow in my lake? Algae grow when they have the right conditions such as adequate nutrients (mostly phosphorus but nitrogen is important too), light levels, pH, temperature, etc. Generally the amount of phosphorus controls the amount of algae found in a freshwater lake or water body. The more nutrient-enriched a lake, typically the more algae in the lake. As Washington lakes and their watersheds are developed, increasing problems are seen with algae. Are there good algae? Healthy lakes need algae. Algae are important to the productivity of a lake or water body. Algae are primary producers.

They use sunlight (through photosynthesis) to produce carbohydrates and are eaten by grazers such as protozoa and zooplankton (little animals like water fleas and rotifers). The zooplankton are, in turn, grazed upon by fish, which are eaten by bigger fish, and on up the food chain. A productive lake produces large fish and good fishing for humans as well as supporting food and habitat for wildlife and waterfowl. In this context most algae are desirable for lakes. Do some kinds of algae cause more problems than other algae? Yes, filamentous green algae and blue-green algae (cyanobacteria) cause the greatest concern with Washington's freshwater body users. Another freshwater algae called Didymo is beginning to cause problems in some of Washington's streams and rivers. Filamentous green algae Filamentous green algae form billowing clouds of slimy or stringy algae in the water. These algae generally grow in nutrient-enriched lakes during the summer and early fall. Mats often form around the tops of aquatic plants. Filamentous green algae can interfere with boater access, recreation, and aesthetics, but are generally harmless. However, many lake groups are concerned with managing the growth of these nuisance algae.

Unlike blue-green algae, filamentous algae can be physically removed from the water. However, techniques such as raking may not be effective when large areas of algae are involved. Mats can grow back quickly. Click here to see a photograph of filamentous algae . Blue-green algae (cyanobacteria) Nutrient-rich lakes or ponds may support rapid growth of blue-green algae (algae blooms). Blue-green algae are actually bacteria. They are called cyanobacteria after the blue-green pigments that they produce. Blue-green blooms can form surface scums up to several inches thick, especially along the shoreline. Cyanobacteria are of greater concern than true algae because some species can produce potent toxins. However, even known toxin-producing species may not produce toxins all the time. If a blue-green bloom is composed of toxin-producing species, it is not possible to determine whether it is producing toxins without special testing. Even then, if a bloom tests non-toxic, it has the potential to become toxic. Therefore people and their pets are warned to avoid contact with surface scums whenever a blue-green bloom is suspected.

Even if blue-green blooms are not toxic or are composed of a species that does not produce toxins, they are unsightly and when they decompose often produce bad odors. Blue-greens are also not very edible. To view a close-up of the photograph (taken by Bijay Adams of Liberty Lake), please click on the photograph. Click here to learn more about cyanobacteria in Washington . For additional information about cyanobacteria see this website. Didymo Didymo (short for Didymosphenia geminata) has been showing up in some Washington rivers. Click here to see a photograph of Didymo . This diatom is normally found in alpine lakes but seems to be expanding its range to lowland rivers. Freshwater diatoms rarely cause problems, but Didymo has started to grow prolifically in some rivers in the United States and in other countries. It has been introduced into New Zealand where it is considered an invasive and noxious species. Didymo forms beige-to-brown mats that are attached by stalks to the river bottom. Another name for Didymo is rock snot and people have described its growth as looking like trailing toilet paper in the river.

Biologists suspect that the presence of this algae has led to trout declines in a South Dakota river (story from the South Dakota Rapid City Journal). In addition to being unsightly, this species may cause habitat alterations. For more information about this emerging problem algae see this website: Didymosphenia Geminata What can I do about algae in my pond or lake? There are no simple answers. Algae may grow for a variety of reasons, but nutrients generally limit algae growth. Any long-term solution to algae management involves nutrient reduction. Taking steps to manage nutrient inputs to a water body is crucial, although many times nutrient management involves managing the entire watershed and not just the area immediately around the lake. Nutrients throughout the watershed may be contributing to the algae problem. Local jurisdictions must become involved with stormwater or agricultural issues or other external nutrient sources. In these cases, lake restoration techniques may be needed. Lake residents can employ best management practices to help reduce nutrients. In the short-term there are control options that may lead to a temporary reduction in the growth of algae. What is that algae in my lake and how can I get it identified? If you are a Washington state resident, the Washington Department of Ecology offers an algal identification service.

If you think that your lake has an algae bloom and you want to have the algae identified, please see this site: Washington State Toxic Algae , and go to the “Report a bloom” tab and follow the instructions. Join Ecology's Freshwater Algae Program List Serve Ecology has set up a list serve for freshwater algae. The Freshwater Algae Program List serve will act as an information exchange and discussion forum about freshwater algae in Washington. A list serve is a program that allows people to send email to one address, which automatically resends that message to all of the other subscribers on the list. If you would like to join the list click here for directions on how to subscribe to the list. Information about Cyanobacteria (Blue-green Algae) Ecology home > Water Quality > Aquatic Plants, Algae, and Lakes > What are Blue-Green Algae (Cyanobacteria)? What are blue-green algae (cyanobacteria)? Cyanobacteria, formerly called "blue-green algae" are relatively simple, primitive life forms closely related to bacteria. Typically much larger than bacteria, they photosynthesize like algae. Depending upon the species, cyanobacteria can occur as single cells, filaments of cells, or colonies.

Cyanobacteria contain a characteristic pigment which gives the group their blue-green coloration. When cyanobacteria blooms begin to die and disintegrate, this pigment may color the water a distinctive bluish color. Cyanobacteria are found throughout the world in terrestrial, freshwater and marine habitats, but blooms typically occur in freshwater. ( see also less technical information about algae in general ) What is a cyanobacteria bloom? Nutrient-rich bodies of water such as some lakes or ponds may support rapid growth of cyanobacteria. With the right conditions, a "clear" body of water can become very turbid with green, blue-green or reddish-brown colored algae within just a few days. High concentrations of an alga species in a water body form "blooms." Many species can regulate their buoyancy and float to the surface to form a thin "oily" looking film or a blue-green scum several inches thick. The film may be mistaken for a paint spill. Cyanobacteria cannot maintain this abnormally high population for long and will rapidly die and disappear after one to two weeks. If conditions remain favorable, another bloom can quickly replace the previous one.

In fact, successive blooms may overlap so that it may appear as if one continuous bloom occurs for up to several months. Why are they a problem? Blue-green blooms can pose a human health concern. Although most blue-green blooms are not toxic, some blue-green algae produce nerve or liver toxins. Toxicity is hard to predict in part because a single species of algae can have toxic and non-toxic strains. Also a bloom that tests non-toxic one day can turn toxic the next day. People may become ill after swimming or water skiing in lakes with toxic blue-green algae. Rarely, humans may experience stomach pains, vomiting, diarrhea, and skin rashes. Nerve and liver damage have been observed following long-term exposure such as drinking water with toxic blooms. Pets and wildlife have died after exposure to toxic blue-green algae in Washington lakes, but worldwide there are no confirmed deaths of humans from algal toxins. Three genera of cyanobacteria account for the vast majority of blooms, including toxic blooms, world-wide: Anabaena, Aphanizomenon, and Microcystis - sometimes referred to as Annie, Fannie, and Mike.

In Washington, Aphanizomenon does not seem to produce toxic blooms, although the other two genera have produced toxic blooms in Washington lakes. A bloom can consist of one or a mix of two or more genera of cyanobacteria. Type of toxins Cyanobacteria can produce several toxins, but two types of toxins are of particular concern and are tested for: Microcystins and Anatoxin-A. Microcystins are a group of hepatoxins (toxins that affect the liver). Microcystins are very stable and do not break down quickly in water. Microcystins are considered to be the most commonly-found cyanobacterial toxins in water and are the toxins most responsible for human and animal poisonings. Anatoxin A is a potent neurotoxin (toxins that affect the nervous system) which can cause lethargy, muscle aches, confusion, memory impairment, and, at sufficiently high concentrations, death. It is believed that a fast-acting algal neurotoxin caused the deaths of two pet dogs at Anderson Lake in Jefferson County in the summer of 2006.

For additional information see Health Canada: Blue-Green Algae (Cyanobacteria) and their Toxins Is a particular bloom toxic? Not all cyanobacteria blooms are toxic. Even blooms caused by known toxin-producing species may not produce toxins or may produce toxins at undetectable levels. Scientists do not know what triggers toxin production by cyanobacteria. Just a few years ago, it was believed that only about 10 percent of all blooms produced toxins. Recent studies have shown that the probability that an individual bloom containing Anabaena, Microcystis, and/or Aphanizomenon will be toxic is greater than previously thought (45-75%). Since cyanobacteria toxins can be lethal to pets in relatively small amounts, caution should always be taken when a bloom occurs. Signs that a cyanobacteria bloom is toxic may be large numbers of dead fish, waterfowl, or other animals within or around a body of water. Terrestrial animals found dead may have algae around the mouth area or on the feet and legs, indicating possible ingestion of and contact with a toxic bloom. Symptoms from sub-lethal poisonings differ with the kind of animal, nature of toxin, and quantity of toxin consumed.

Any sudden, unexplained animal illness or death occurring near a water body containing a bloom should be suspect. There have been no confirmed deaths in humans due to consumption of bloom toxins. However, some blooms have caused "outbreaks" of dermatitis (a form of "swimmers itch") and attacks of gastroenteritis in groups of swimmers. These causative agents appear not to be the same toxins as the potentially lethal toxins. Only laboratory tests can confirm whether a bloom is toxic or non-toxic. If you live in Washington state and you want to report a cyanobacteria bloom and have it tested, please see this site Washington State Toxic Algae , go to the "Report a bloom" tab and follow the instructions. Where can blooms be found? Cyanobacteria blooms have been documented throughout Washington State. Blooms can occur in any nutrient-rich standing water such as lakes, ponds, roadside ditches, sewage lagoons, or overflows and embayments of rivers. Chemical and physical factors needed for a bloom to form or produce toxin are complex and not fully understood. However, certain requirements are known which include elevated nutrients such as nitrogen and phosphorus, pH 6-9, and temperatures which can support cyanobacteria.

Some species of cyanobacteria can also "fix" nitrogen from the atmosphere. These nitrogen-fixing species are not dependent on other nitrogen sources. They have a competitive advantage over non-nitrogen-fixing species when water nitrogen concentrations are low. Because cyanobacteria are mostly photosynthetic, they may be limited by availability of light, although they can grow under relatively low light conditions. When can blooms occur? According to scientific literature, cyanobacteria most commonly occur in late summer and early fall when water temperatures reach 72°-80° F. At these temperatures, cyanobacteria grow rapidly and may create a bloom within a few days. Most blooms east of the Cascade mountains in Washington follow the classic scenario and are visually observed in late summer and early fall. Data collected in Western Washington lakes have shown cyanobacteria blooms during atypical water temperatures and times of the year. Although an individual lake in Western Washington may have a predictable bloom season, this season may vary dramatically between lakes. Based upon preliminary evidence, a bloom may be found somewhere in Western Washington nearly any month of the year and at water temperatures as low as 45°-50° Fahrenheit (7°-10° Celcius).

What can I do about blue-green algae? While there are short-term treatment options for controlling algae , the long-term solution involves finding ways to reduce nutrient inputs into the water body. Finding and reducing external nutrient inputs to the water body is crucial for long-term success and lake recovery. There are best management practices that lake residents can follow and there are some in-lake management options that may help reduce nutrients or algae problems. Once a bloom has formed, treating it with algaecides is probably not a good idea. Most chemical treatments can cause the cells to break open, releasing toxins into the water. Many cases of human poisoning from algal toxins have occurred after chemical treatments of blue-green blooms. Acknowledgements Most of the above information is from Toxic Cyanobacterial Blooms - A Field/Laboratory Guide. This guide was written by Dr. M. A. Crayton from Pacific Lutheran University, Tacoma, Washington and edited by Dr. F. Joan Hardy, Washington State Department of Health. Used with permission. Copyright © Washington State Department of Ecology. See Harmful Algal Blooms (HABs) - NYS Dept.

of Environmental Conservation Harmful Algal Blooms (HABs) What are Harmful Algal Blooms (HABs)? Most algae are harmless and are an important part of the food web. Certain types of algae can grow quickly and form blooms, which can cover all or portions of a lake. Even large blooms are not necessarily harmful. However some species of algae can produce toxins that can be harmful to people and animals. Blooms of algae species that produce - or have the potential to produce - toxins are referred to as harmful algal blooms (HABs). HABs blooms most often occur in nutrient-rich waters, particularly during hot, calm weather. Keep reading for an overview of HABS and how to keep you and your loved ones safe. Click on the links below for more detailed information. Avoid Algal Blooms Because it is hard to tell a HAB from other non-harmful algae blooms, it is best to avoid swimming, boating, otherwise recreating in, or drinking water with a bloom. DEC strongly recommend avoiding all contact with any floating mats, scums, or discolored water.

It is not easy to tell by looking at it if a bloom will produce toxins or other compounds that can be harmful to human health or animals. Laboratory analysis of a water sample is needed to confirm the presence of toxins. Before you go in the water, find out what waterbodies have blooms or have had them in the past. DEC maintains a HABs Notifications page of waterbodies that currently have blooms. Please note that if a waterbody is not listed, it does not mean that it does not have a bloom. It may have one that was not reported. Find out what waterbodies have had blooms in the past on the HABs Archive page . Algae blooms may have the appearance of spilled green paint. Freshwater Blue-green Algal Blooms Cyanobacteria (also known as blue-green algae), are naturally present in lakes and streams in low numbers. Cyanobacteria HABs are the most common type of blooms in New York. Sometimes, depending on environmental conditions, cyanobacteria can grow very quickly and produce blooms with high numbers of cells. Cyanobacteria can form blooms that discolor the water or produce floating scums on the surface of the water.

HABs can reduce the recreational value of a waterbody, due to unpleasant appearances and odors. HABs cause a variety of ecological problems, such as reduced oxygen levels. The factors that cause cyanobacteria to produce toxins and other harmful compounds are not well understood. Marine Algal Blooms HABs can form in marine waters, producing marine blooms and a variety of biotoxin events that occur off the coast of New York and other eastern and coastal states. The DEC Bureau of Marine Resources has a Marine Biotoxin Monitoring Program to search for the presence of toxin-producing marine algae (Alexandrium and others) and to detect marine biotoxins in shellfish, such as clams, mussels and oysters. What should I do if I see or come in contact with a bloom? HABs may have the appearance of pea soup. If you see it - avoid it People, pets and livestock should avoid contact with water that is discolored or has algae scums on the surface. Colors can include shades of green, blue-green, yellow, brown or red. If contact does occur, rinse thoroughly with clean water to remove algae. Never drink untreated surface water, whether or not algae blooms are present.

Untreated surface water may contain other bacteria, parasites or viruses, as well as cyanotoxins that could cause illness if consumed. People not on public water supplies should not drink surface water during an algal bloom, even if it is treated, because in-home treatments such as boiling, disinfecting water with chlorine or ultraviolet (UV), and water filtration units do not protect people from HABs toxins. Stop using water and seek medical attention immediately if symptoms such as vomiting, nausea, diarrhea, skin, eye or throat irritation, allergic reactions or breathing difficulties occur after drinking or having contact with blooms or untreated surface water. Please report any health symptoms to NYS Health Department at harmfulalgae@health.ny.gov and your local health department (link leaves DEC website.) For answers to other frequently asked questions go to the DEC HABs FAQ page. If you suspect that you have seen a HAB or you, your family, or pet has been in contact with a bloom, please report the bloom to the DEC.

Fill out and submit a Suspicious Algal Bloom Report Form (PDF, 763 KB) .Email the completed form and, if possible, attach digital photos (close-up and landscape to show extent and location) of the suspected bloom to HABsInfo@dec.ny.gov . What is New York State doing ? The DEC, the NYS Department of Health (DOH), and the NYS Office of Parks, Recreation and Historic Preservation (OPRHP) are working together to identify and respond to HABs concerns. DEC and DOH coordinate field personnel to investigate HABs reports. DEC and DOH are conducting research to learn more about HABs and to evaluate their risks to public health and the environment. You may also contact your regional DEC office or contact: DEC HABs Program Coordinator: Rebecca Gorney, Ph.D., Division of Water Phone: (518) 402-8179 Algae – Plant Management in Florida Waters Cladophora species are also bright green. They are branching, and feel coarse when touched. Hydrodictyon Hydrodictyon (also called water net) forms a net by joining five or six cylindrical cells.

It can grow so large that the net can be seen by the naked eye. The best habitat is clear, eutrophic water, but the algae are also seen in irrigation ditches and even rice fields. Bacillariophyta Diatoms Diatoms are a group of algae often considered the most beautiful because of the glass-like silica shell that houses them. These "shells" come in a wide variety of shapes and sizes and some species can form long chains when linked together. Their appearance is somewhat kaleidoscopic. Xanthophyta Commonly called yellow-green algae, many species belonging to this group were once placed within Chlorophyta. However, the classification was changed after close observation of the type of chlorophyll and its arrangement. Vaucheria Vaucheria species are filamentous, with branched cells; they grow in dense mats that look like carpets of green felt. Charophyta Charophyta species (commonly called the stoneworts) are considered an evolutionary link to higher plants. They occur in lakes, ponds, and streams attached to the bottom by rhizoids. This group is often mistaken for true plants because of the whorls of filaments at nodes along the shoot of the organism.

Charophyta can form relatively large areas of dense underwater monocultures. Chara Chara Chara is commonly called muskgrass because of its distinctive odor. This submersed alga grows in slow-moving rivers and lakes, and can overtake other natural vegetation. Chara has a strong musk or garlic odor when crushed. It is coarse to the touch. Nitella, a submersed alga, grows in slow-moving rivers and lakes. It looks like Chara, but does not feel rough when touched. It is gray-green or yellow and grows in shallow and deep water attached to the substrate. Some species are a few inches tall; others are three feet or longer. What causes an algae bloom? Algae bloom in Merrits Mill Pond In Florida, chlorophyll (an indicator of algae presence) concentrations of more than 40 micrograms per liter are called an “algae bloom” or “algal bloom.” Algae blooms occur when algae grows quickly and densely, often in warm, nutrient-rich waters. Although these blooms are natural, many people don't like their appearance. Blooms associated with phytoplankton (microscopic algae) turn the water a certain color.

Algae blooms are commonly green, but they can also appear blue-green, brown, red, or violet. Other blooms form clumps or dense mats that float on the surface of the water, grow attached to the bottom, or attach to plants. Algae need light and nutrients, such as nitrogen and phosphorous, to grow. The level of growth or productivity often depends on the amount of nutrients in a system. Classification for the productivity of a system ranges from oligotrophic (low productivity and nutrients) to hypereutrophic (very high nutrients).Since algae need light to photosynthesize , light penetration into the water is another limiting factor. Blooms can have far-reaching effects on the environment. Some become so dense they deplete oxygen levels. Decreased oxygen can cause hypoxia (low oxygen) or anoxia (no oxygen) and other organisms that use oxygen, such as fish, become stressed and may die. Other blooms can release toxins that are harmful to animals. There is a general consensus that urban development, and the subsequent increase in nutrients, has increased the frequency and intensity of algal blooms in many regions of the world. Controlling algal blooms The most direct way to control algal blooms is to reduce the availability of nutrients.

Most water management organizations throughout the world are actively pursuing a variety of nutrient-reduction strategies. However, for some aquatic ecosystems, nutrient reduction is impractical, ineffective, or too expensive. In some cases, chemical or biological treatments are helpful alternatives. Chemical Treatments Copper sulfate and chelated copper compounds are common chemical treatments to control algae. Chemical compounds that block the light required for algae growth (for example, dyes such as Aquashade) are also used to control blooms. Municipal water authorities often treat drinking-water reservoirs when the algal count exceeds a certain number. Blue-green algae usually increase late in the summer, and often impart a foul taste and odor to the water. When this happens, copper herbicides are applied to lower the algal count, thus making the water more acceptable to drink. Biological Treatments The main biological treatment used today is fish stocking to control submersed and floating algae. Grass carp (Ctenopharyngodon idella) are mainly used for aquatic weeds and attached submersed algae, such as Nitella sp., and Chara sp. Although they do not readily eat filamentous algae, grass carp will eat Lyngbya.

The silver carp (Hypophthalmichthys molitrix) has been an effective control for filamentous algae, including blue-green algae. Both species of carp are non-native, and there are many restrictions to using them for weed control purposes; some states prohibit their use altogether. When they are allowed, use is restricted to triploid grass carp. Triploid grass carp have an extra set of chromosomes that render them sterile, prohibiting reproduction if the fish escapes into open water. These fish are an economical choice and have proven effective in controlling the growth of algae in some circumstances. However, outcomes have been mixed when using carp to control algal blooms. Grass carp may consume beneficial vegetation, and leave the nuisance algae they were intended to eat. Research is being conducted on how and why feeding preferences change over time and vary from one lake to another. Physical Treatments Physical treatments for algae in ponds include aeration and airlifts. While aeration does not kill or remove algae from the water, it stirs and oxygenates the water, and can shift conditions from toxic and foul-smelling blue-green algae to preferred green algae species. The resultant algal population is usually not as dense or toxic to other organisms in the ponds.

Mechanical Treatments Harvesters are sometimes used to skim dense mats of blue-green algae (Lyngbya) from the water surface. Lyngbya typically grows in dense mats at the bottoms of nutrient-enriched lakes and spring-fed systems. During photosynthesis, these mats produce gasses that cause them to rise to the surface. Winds pile the algal mats, sometimes several acres in size, against shorelines or in navigation channels. Managers have developed a process called "grubbing" whereby harvesting machines lift the mats off of submersed plants such as native eelgrass, without cutting the eelgrass. By removing the blanket of Lyngbya from the eelgrass, the native plants are able to grow unobstructed. Eelgrass is an important food source for manatees in the Crystal and Homosassa Rivers. Search What are Harmful Algae? What are Harmful Algae? What are Harmful Algae? What are harmful algae? Phytoplankton blooms, micro-algal blooms, toxic algae, red tides, or harmful algae, are all terms for naturally occurring phenomena.

About 300 hundred species of micro algae are reported at times to form mass occurrence, so called blooms. Nearly one fourth of these species are know to produce toxins. The scientific community refers to these events with a generic term, ‘Harmful Algal Bloom’ (HAB), recognising that, because a wide range of organisms is involved and some species have toxic effects at low cell densities, not all HABs are ‘algal’ and not all occur as ‘blooms’. Why are they harmful? Proliferations of microalgae in marine or brackish waters can cause massive fish kills, contaminate seafood with toxins, and alter ecosystems in ways that humans perceive as harmful. A broad classification of HABs distinguishes two groups of organisms: the toxin producers, which can contaminate seafood or kill fish, and the high-biomass producers, which can cause anoxia and indiscriminate kills of marine life after reaching dense concentrations. Some HABs have characteristics of both. Olive green discolouration of the waters of False Bay by the dinoflagellate Gymnodinium cf.

mikimotoi - In addition to faunal mortalities, this species is also the cause of a type of NSP and the production of aerosol toxins causing skin and respiratory irritations to humans. Photograph by G.C. Pitcher. Although HABs occurred long before human activities began to transform coastal ecosystems, a survey of affected regions and of economic losses and human poisonings throughout the world demonstrates very well that there has been a dramatic increase in the impacts of HABs over the last few decades and that the HAB problem is now widespread, and serious. It must be remembered, however, that the harmful effects of HABs extend well beyond direct economic losses and impacts on human health. When HABs contaminate or destroy coastal resources, the livelihoods of local residents are threatened and the sustenance of human populations is compromised. Harmful algae and marine food resources The impact of harmful microalgae is particularly evident when marine food resources,e.g. aquacultures, are affected. Shellfish and in some cases finfish are often not visibly affected by the algae, but accumulate the toxins in their organs. The toxins may subsequently be transmitted to humans and through consumption of contaminated seafood become a serious health threat.

Although the chemical nature of the toxins is very different, they do not generally change or reduce significantly in amount upon cooking; neither do they generally influence the tate of the meat. Unfortunately, detection of contaminated seafood is not straight forward, and neither fishermen nor consumers can usually determine whether seafood products are safe for consumption. To reduce the risk of serious seafood poisoning intensive monitoring of the species composition of the phytoplankton is required in the harvesting areas in connection with bioassays and/or chemical analyses of the seafood products. Hydrogen sulphide poisoning - In March 1994, a massive marine mortality was experienced in St Helena Bay on the South African west coast22. This event was caused by the entrapment and subsequent decay of an expansive red tide dominated by the dinoflagellates Ceratium furca and Prorocentrum micans. Marine life died from both suffocation and hydrogen sulphide poisoning. Oxygen concentrations were maintained at <5.5 ml.l-1 in the bottom waters of the Bay and hydrogen sulphide, subsequently generated by anaerobic bacteria in the absence of dissolved oxygen, was recorded in excess of 50 µmol.l-1.

Approximately 60 tons of rock lobster and 1500 tons of fish, comprising about 50 species, washed ashore. The mullet Liza richardsoni made up the bulk of the fish mortality, with the remainder dominated by sharks and bottom-dwelling fish. The production of hydrogen sulphide gas caused the sea to turn black, and the event was soon dubbed the "black tide" by the media. Although common in the northern Benguela, this was the first recorded incidence of hydrogen sulphide poisoning in the southern Benguela. Photograph - The Argus In addition to posing serious health risks to consumers of seafood, some microalgae may have devastating effects on fish and other marine life, both in wild and aquacultures. Several species of micro algae belonging in different taxonomic groups can produce toxins which damage fish gills by hemolytic effects. This has resulted in extensive fish kills with major economic losses. A comprehensive economic analysis of the global impact of harmful algal events on the aquaculture industry is not available, but the economic losses from single event in North America and especially Japan have on several occasions amounted to more than US$ 10 million.

On one particular occasion the raphidophyte flagellate Chattonella antiqua killed US$ 500 million worth of caged fish in Japan. Additional losses may be inferred from public miscredit of seafood products due to misunderstandings and misinformations about harmful algal events. In developing countries, seafood often constitutes an important or even sole source of food and protein, especially in costal areas. With the increasing problems of overfishing, aquaculture may become an increasingly important alternative for the supply of seafood. However, to minimize the risk of sea-food poisonings and the risk of major economic losses due to fish kills, it is important to establish adequate surveillance programmes and quality control of the seafood products which will often require expert assistance from countries which have longstanding experience in this matter. Toxic effects on humans Particularly in the tropics people are often harassed by diseases and syndroms due to consumption of seafood contaminated by algal toxins. Some of these diseases may be fatal. There is currently no international record of the number of incidents of human intoxication caused by contaminated seafood.

The numbers appearing in presentations at international meetings are undoubtedly underestimates, as many cases and even fatalities can be assumed to pass undiagnosed and hence unreported in the official reports. Five human syndroms are presently recognized to be caused by consumption of contaminated seafood: amnesic shellfish poisoning - ASP neurotoxic shellfish poisoning - NSP paralytic shellfish poisoning - PSP Other threats to human health are posed by blue-green algal toxins in drinking water which may cause severe damage or be tumor promoters. Amnesic shellfish poisoning - ASP This syndrome can be life-threatening. It is caused by domoic acid that accumulates in shellfish, but the disease can apparently also be fish borne, so the risk to humans may be more serious than previously believed. It is characterized by gastrointestinal and neurological disorders including loss of memory. Human ASP intoxication is presently known primarily from Canada, but the causative diatoms occur in many parts of the world, so considerable care should be exercised during blooms of species of the diatom Pseudo-nitzschia. Ciguatera fish poisoning - CFP This poisoning, transmitted by several tropical reef fish, is generally not lethal, although fatalities have been documented.

Ciguatera produces gastrointestinal, neurological and cardiovascular disturbances, and recovery often takes months or even years. It is widely distributed in the tropics; thus in the period 1960-1984, there were a total of 24.000 cases of ciguatera in French Polynesia alone. Evidence is accumulating that disturbances of coral reefs by hurricanes, tourist activity etc. increase the risk of ciguatera by providing more suitable habitats for the benthic dinoflagellates (see causative organisms). There is at present no easy method to routinely measure the toxins (ciguatoxin and maitotoxin) that cause ciguatera fish poisoning. Diarrhetic shellfish poisoning - DSP This is a wide spread type of shellfish poisoning which causes gastrointestinal disturbances with diarrhea, vomiting, and abdominal cramps. If is not fatal, and the patients usually recover within a few days. There are thousands of reported incidents from developed countries, e.g. 5000 in Spain in 1981 alone, but with the pathological picture of DSP, many incidents may be regarded as an ordinary stomach disorder, and therefore remain unreported.

Chronic exposure to DSP is suspected to promote tumor formation in the digestive system. Neurotoxic shellfish poisoning - NSP Until recently this syndrome has been restricted to the Gulf of Mexico, but in 1993 it was reported also from New Zealand. It is characterized by gastrointestinal and neurological disturbances usually with recovery within a few days. Toxic aerosols formed by wave action may cause asthma-like symptoms. Paralytic shellfish poisoning - PSP This is a life-threatening syndrome with neurological effects. The is no known antidote to PSP. The known global distribution has increased markedly over the last few decades. Each year about 2000 cases of PSP are reported with 15 % mortality. Which are the causative organisms? Many of the syndromes and other harmful effects pertain to occurrences of dinoflagellates. There is, however, an increasing number of species recognized as toxic in other algal classes, and harmful species are now found in at least 5 groups of algae: Dinophycae (= Dinoflagellates) Species of Dinoflagellates are responsible for ciguatera, DSP, NSP, and PSP.

Ciguatera is caused by Gamberidiscus toxicus, and perhaps also by some species of Ostreopsis and Prorocentrum. Most of these species can readily be identified by trained taxonomists. PSP is caused by several species. Most cases are caused by Pyrodinium bahamense var. compressum and species of Alexandrium. The latter genus comprises about 30 species which are difficult to identify. They are distinguished by small differences in the plate structure of the plates covering the cell. DSP is caused by by several species of Dinophysis and some species of Prorocentrum. Dinophysis is a large genus with some 200 described species many of which pose considerable taxonomic problems. Species are distinguished only by morphological features such as size, shape, presence/absence of chloroplasts etc. Thus the circumscription of many species is vague and a comprehensive taxonomic revision of this genus is needed. NSP is caused by Gymnodinium breve.

In adition to the human syndromes caused by dinoflagellates, extensive fih kills have been caused by several so-called unarmoured species belonging in the genera Amphidinium, Cochlodinium, and Gymnodinium. Identification of these is generally difficult and requires examination of live cells. Prymnesiophycae (= Haptophycae) Species of Chrysochromulina and especially Prymnesium have caused fish kills on many occasions, but have never been reported to be a threat to human health. The species of both genera are generally well circumscribed, but critical identification to species level requires electron microscopy to examine the micromorphology of the scales covering the cell surface. Raphidophycae This class includes species which are responsible for the most extensive fish kills reported so far. Most species deteriorate upon preservation and critical identification generally requires observation of live cells. Bacillariophycae (= Diatoms) ASP is caused by Pseudo-nitzschia australis, P. multiseies, and perhaps P. pseudoelicatissima.

The two latter species are widly distributed an both the Northern and Southern Hemispheres, while the former occurs mostly in the Southern Hemisphere. Species identification is difficult often requiring electron microscopy, and misidentifications probably occur in the literature. Cyanophycae (= Blue-green algae) In the marine environment, only few species of blue-green algae cause problems, e.g. species of Trichodesmium and Nodularia, and these have not been associated with human syndroms so far. A wide variety of blue-green algae cause serious problems in fresh and brackish water environments and may be a serious health problem where surface water is used for drinking water supplies. What to do about them? Identification of the causative species When harmful algae occur, an immediate and essential action is reliable identification of the causative species involved for a first assessment of the potential risks. Many species are difficult to identify and advanced taxonomic training is necessary. Application of modern taxonomic concepts requires in some cases electron microscopy for critical identification, and this equipment is not generally available in many countries (particularly developing countries). There is often also a scarcity of scientific literature and/or limited access to libraries which is essential for both monitoring and scientific work.

Advice to those fishing, gathering shellfish or swimming As it is impossible to see with the naked eye whether there are harmful algae in the water, examination of the water or seafood in the laboratory is necessary to determine the presence of harmful algae or algal toxins. Even after authorities have monitored an area there is no guarantee that there are no toxins present. The toxicity of can vary from locality to locality and from day to day. Most authorities therefore monitor whether there is a potential danger of toxicity. The best you can do is always to follow some general advice: When fishing do not fish in the middle of an algal bloom/discoloured water never eat fish which are dead when caught When gathering shellfish be aware of the intoxication symptoms if you experience any symptoms, keep a sample of the shellfish for toxicity testing When swimming look for warnings against algal blooms never allow children to swim if there is a risk of algal toxins in the water never swim if you cannot see you feet when the water level is at your knees See a doctor if you or your children get sick after eating seafood or swimming To give the doctor the best background for finding out why you are sick it is adviseable to bring a sample of the seafood, or the water in which you swam.

WHO is currently preparing guidelines for safe recreational water enviroments. More information can be obtained from: WHO , Water, Sanitation and Health Unit Department of the Protection of the Human Enviroment 20 Avenue Appia, Tel. +41 22 791 35 37 Fax. +41 22 791 41 59 e-mail. This email address is being protected from spambots. You need JavaScript enabled to view it. Harmful algae as invasive species Several countries have prepared, or are in the process of preparing, white, grey and black lists of alien invasive species (Re e.g. European Strategy on Invasive Alien Species). With regard to marine species, harmful algae naturally come up as a group of organisms of interest. As the number of potential harmful invasive micro algae species is beyond what is practical to list, one approach may be to list those: Criteria 1: Toxic Harmful Algal Blooms (HABs) Photo Gallery - NYS Dept.

of Environmental Conservation Enter Search Term(s): Search DEC Skip to main navigation Harmful Algal Blooms (HABs) Photo Gallery The photos on this page provide examples of what a harmful algal bloom (HAB) may look like. For comparison, photos of non-toxic blooms are also provided. It can be hard to tell a HAB from other non-toxic algal blooms and sometimes several types of algae can be present at one time. DEC recommends avoiding contact with any floating mats, scums, or discolored water. If you see an algal bloom and think it may be a HAB, please submit a Suspicious Algal Bloom Report Form (764 KB) . Email the completed form with digital photographs (close-up and landscape to show extent and location) of the suspected bloom to HABsInfo@dec.ny.gov . Algae is an important part of aquatic ecosystems and forms the basis of lake food chains. There are many types of algae commonly found in the freshwaters of New York. The most common types of HABs are made up of blooms of cyanobacteria (also known as blue-green algae).

Individual algae cells cannot be seen with the unaided eye, however, under certain conditions they can cluster together and form visible colonies called blooms. What do Harmful Algal Blooms (HABs) look like? HABs may look like parallel streaks, usually green, on the water surface. HABs may look like green dots, clumps or globs on the water surface. HABs may look like blue, green, or white spilled paint on the water surface. HABs may make the water look bright green or like pea soup. What do non-toxic green algal blooms look like? Green algae can look like floating rafts on the water, but do not produce harmful toxins. Green algae can look like bubbling scum on the water and may be entangled with other plant material, but do not produce harmful toxins. Green algae can look silky, hairy or like wet fabric on the rocks, plants or water surface, but do not produce harmful toxins. Green algae can look stringy or hairy or like a tumbleweed in the water or on the lake bottom, but do not produce harmful toxins. Green algae can form thick mats on the water surface but do not produce harmful toxins.

Although duckweed can cover the water surface, it is not algae, and does not produce harmful toxins. It is a tiny aquatic plant with a grainy texture and looks like a miniature lilypad. (Photo: Ohio EPA)

Question: A form of invasive toxic freshwater algal bloom known as blue-green is caused by what?
Answer: Cyanobacteria