Harmful algal blooms

From Wikipedia, the free encyclopedia
  (Redirected from Harmful algal bloom)
Jump to: navigation, search
A dog swimming though an algal bloom

A harmful algal bloom (HAB) is the rapid and uncontrolled growth of algae in either freshwater or marine environments. Because some algae produce toxins, they can be harmful to humans, mammals, birds and fish when the toxins are ingested.

Blooms can last from a few days to many months. While they grow, they deplete the oxygen in the water along with blocking sunlight from reaching fish and plants. After the bloom dies, the microbes which decompose the dead algae use up even more of the oxygen, which can create fish die-offs. When these zones of depleted oxygen cover a large area for an extended period of time, they are referred to as dead zones, where neither fish nor plants are able to survive.

Among the causes of HABs are high-nutrient conditions in water, mostly of nitrates and phosphorus which are emitted by agriculture and other industries. Higher water temperature and less circulation are also factors. HABs can cause significant harm to animals, the environment and economies. They have been increasing in size and frequency worldwide.


A harmful algal bloom (HAB) is the rapid and uncontrolled growth of algae in either freshwater or marine environments which can cause harm to animals, people, or the local ecology.[1] They cause injury by producing toxins, blocking the sunlight or by using up the oxygen needed by fish or plant life. HABs in marine environments are often referred to as red tides.[2]

HABs can also cause significant economic harm to fisheries, recreation and tourism, which then requires constant monitoring and management. An increasing occurrence of HABs has become evident globally.[2]


Blue-green (Cyanobacteria) algae bloom on Lake Erie in 2009

There are three main types of algae which can form into harmful algal blooms: cyanobacteria, dinoflagellates and diatoms. All three are made up of microscopic floating organisms which, like plants, can create their own food from sunlight by means of photosynthesis. That ability makes them an essential part of the food web for small fish and other organisms.[3]:246

Blue-green algae[edit]

Harmful algal blooms in freshwater lakes and rivers, or at estuaries, where rivers flow into the ocean, are caused by blue-green algae, also known as Cyanobacteria.[4] They can produce hazardous toxins, such as microcystins,[5] a neurotoxin which destroys nerve tissue of mammals.[6] In high enough concentrations, water treatment plants may be unable to remove the toxin and will advise residents to avoid drinking tap water, as happened in Toledo, Ohio in August 2014.[7]

They also cause harm by blocking the sunlight or by using up the oxygen needed by fish or plant life, which can lead to fish die-offs.[8] When such oxygen-depleted water covers a large area for an extended period of time, it can become a dead zone.

Red tides[edit]

A red tide off the coast of San Diego

The other types of algae are diatoms and dinoflagellates, found primarily in marine environments, such as ocean coastlines or bays, where they can also form algal blooms, commonly called red tides. Red tides, however, may be a natural phenomenon,[9] although when they form close to coastlines or in estuaries, they are usually caused by agriculture or industry. They can occur when water temperature, salinity, and nutrients reach certain levels, which then stimulates the growth of algae.[9]

About 50% of red tide species and 75% of HAB species are dinoflagellates.[2] In testing for their density in water, a concentration of 1,000 algal cells per milliliter is visible to the naked eye. In August 2015, one marine scientist measured a density of 200,000 per milliliter in the Chesapeake Bay.[10]

Diatoms produce domoic acid, another neurotoxin, which can cause seizures in higher vertebrates and birds as it concentrates up the food chain.[11] Domoic acid readily accumulates in the bodies of shellfish, sardines, and anchovies, which if then eaten by sea lions, otters, cetaceans, birds or people, can affect the nervous system causing serious injury or death.[11] In the summer of 2015, the state governments closed important shellfish fisheries in Washington, Oregon and California because of high concentrations of domoic acid in shellfish.[12]

Description and identification[edit]

Algae on the coast of northern Germany

HABs from blue-green algae can appear as a foam, scum, or mat on or just below the surface of water and can take on various colors depending on their pigments.[1] Blue-green algae blooms in freshwater lakes or rivers may appear bright green, often with surface streaks which looks like floating paint.[13] Similarly, red tides made up of dinoflagellates, also contain photosynthetic pigments that vary in color from green to brown to red.

Most blooms occur in fresh, marine, or brackish waters that have excessive nutrients and above normal water temperature which stimulate their rate of growth.[1] The harmful effects from such blooms is due to the toxins they produce or from using up oxygen in the water which can lead to fish die-offs.[8]

Not all algal blooms are harmful, however, with some only discoloring water, producing a smelly odor, or adding a bad taste to the water. Unfortunately, it is not possible to tell if a bloom is harmful from just appearances, since sampling and microscopic examination is required.[1]


Among the causes of algal blooms are chemical wastes, primarily phosphorus and nitrates from fertilizers,[14][4] climate change with its resultant global warming[14][15] and low water levels in inland waterways and lakes which reduces water flow and increases temperature.[6][16] Still, warm, shallow water, combined with high-nutrient conditions in lakes or rivers, increases the risk of harmful algal blooms.[16]

Those chemicals enter freshwater or marine environments from runoff of sewage and agricultural wastes along with nitrates and phosphates introduced from atmospheric pollution.[17] Coastal areas worldwide, especially wetlands and estuaries, coral reefs and swamps, are prone to being overloaded with those nutrients which can develop into rapid and massive algal blooms.[17] Most of the large cities along the Mediterranean Sea, for example, discharge all of their sewage into the sea untreated.[17] The same is true for most coastal developing countries.

In the U.S., such runoff, despite being the largest source of nutrients added to rivers and lakes, is mostly unregulated under the federal Clean Water Act.[18] To help reduce algal blooms in Lake Erie, Ohio presented a plan in 2016 to reduce phosphorus runoff.[19]

The Chesapeake Bay estuary, the largest in the U.S, has suffered from repeated large algal blooms for decades due to runoff from multiple sources.[20] Chemical nutrients are fed into the bay from 9 large rivers and 141 smaller streams and creeks in parts of six states. In addition, the water is quite shallow and only 1% of the waste entering it gets flushed into the ocean.[17] By weight, 60% of the phosphates coming into it as of 2003 were from sewage treatment plants, while 60% of its nitrates came from fertilizer runoff, farm animal waste, and the atmosphere.[17] About 300 million pounds of nitrates are added to the bay each year.[21]

The increase in the bay's population from 3.7 million in 1940 to 18 million in 2015 is also a major factor.[17] And such rapid population and economic growth elsewhere have also been driving factors in their use of fertilizers.[22][23] Many large areas where the oxygen continues to be depleted by blooms eventually become dead zones, where neither fish nor plants are able to survive.[24] Such dead zones in the case of the Chesapeake Bay, where they are a normal occurrence, are also suspected of being a major source of methane.[25]

According to a NOAA expert, "some of the features of climate change, such as warmer ocean temperatures and increased light availability through the loss of sea ice in the Arctic, are making conditions more favorable" for toxic and non-toxic algae growth in more regions and farther north. "Climate change was working against efforts to prevent algal blooms," said another expert.[26]

Blooms produce turbid water which blocks sunlight to lower levels. Such blooms can last from a few days to many months.[27] With less light, plants beneath the bloom can die and fish can starve. When the algae eventually die off, the microbes which decompose the dead algae use up the available oxygen, which in turn causes even more fish to die. The negative impact on fish can be even more severe when they are confined to pens, as they are in fish farms. In 2007 a fish farm in British Columbia lost 260 tons of salmon as a result of blooms,[28] and in 2016 a farm in Chile lost 23 million salmon after an algal bloom.[29]

Harmful effects[edit]

According to the National Oceanic and Atmospheric Administration (NOAA), less than one percent of algal blooms produce hazardous toxins, such as microcystins.[5] Although blue-green or other algae do not usually pose a direct threat to health, the toxins (poisons) which they produce are considered dangerous to humans, land animals, sea mammals, birds[27] and fish when the toxins are ingested.[5] The toxins are neurotoxins which destroy nerve tissue which can affect the nervous system, brain, and liver, and can lead to death.[6]

There is no treatment available for animals, including livestock cattle, if they drink from algal blooms where such toxins are present. The Florida Department of Health recommends that people and pets be kept away from algal blooms to avoid contact.[30]

Human health[edit]


Eating fish or shellfish from lakes with a bloom nearby is not recommended.[13] Toxic paralytic shellfish poisoning took place in the Philippines during a red tide, leading to 120 deaths between 1983 and 2002.[31] After a HAB in Monterey Bay California, health officials warned people not to eat certain parts of anchovy, sardines, or crab caught in the bay.[32] In 2015 most shellfish fisheries in Washington, Oregon and California were shut down because of high concentrations of toxic domoic acid in shellfish.[12] And simply inhaling toxic vapors from waves and wind during a red tide may cause asthma attacks or lead to other respiratory ailments.[33]

Some agricultural officials in Utah are worried that even crops could become contaminated from using toxic water, although they admit that they can't measure contamination accurately because of so many variables in farming. They issued warnings to residents out of caution.[34]

Drinking water[edit]

Satellite image of Lake Erie during an algal bloom in 2011

Persons are generally warned not to enter or drink water from algal blooms, or let their pets swim in the water since many pets have died from algal blooms.[16] In at least one case, people began getting sick before warnings were issued.[35]

In some locations visitors have been warned not to even touch the water.[13] Boaters have been told that that toxins in the water can be inhaled from the spray from wind or waves.[4][13] Ocean beaches,[15] lakes[6] and rivers have been closed due to algal blooms.[27] After a dog died in 2015 from swimming in a bloom in California's Russian River, officials likewise posted warnings for parts of the river.[36] Boiling the water at home before drinking does not remove the toxins.[13]

Scientists in Britain, which has seen a huge increase in toxic algae, suspect that drinking water from sources that have blue-green algae may contribute to Alzheimer’s, Parkinson’s or Lou Gehrig’s Disease. Few water treatment plants regularly test for cyanobacterial toxins, however.[37]

In August 2014 the city of Toledo, Ohio advised its 500,000 residents to not drink tap water as the high toxin level from an algal bloom in western Lake Erie had affected their water treatment plant's ability to treat the water to a safe level.[7] The emergency required using bottled water for all normal uses except showering, which seriously affected public services and commercial businesses. The bloom returned in 2015[38] and was forecast again for the summer of 2016.[39]

In 2004, a bloom in Kisumu Bay, which is the drinking water source for 500,000 people in Kisumu Kenya, suffered from similar water contamination.[40] In China, water was cut off to residents in 2007 due to an algal bloom in its third largest lake, which forced 2 million people to use bottled water.[41][42] A smaller water shut-down in China affected 15,000 residents two years later at a different location.[43] Australia in 2016 also had to cut off water to farmers.[44]

A dead fish in Lake Erie during an algal bloom

Professor Alan Steinman explains that among the major causes for the algal blooms in general, and Lake Erie specifically, is because blue-green algae thrive with high nutrients, along with warm and calm water. Lake Erie, he says, is more prone to blooms because it has a high nutrient level and is shallow, which causes it to warm up more quickly during the summer.[45]

Symptoms from drinking toxic water can show up within a few hours after exposure. They can include nausea, vomiting, and diarrhea, or trigger headaches and gastrointestinal problems.[6] Although rare, liver toxicity can cause death.[6] Those symptoms can then lead to dehydration, another major concern. In high concentrations, the toxins in the algal waters when simply touched can cause skin rashes, irritate the eyes, nose, mouth or throat.[13] Those with suspected symptoms are told to call a doctor if symptoms persist or they can't hold down fluids after 24 hours.

Economic impact[edit]

Recreation and tourism[edit]

The hazards which accompany HABs have hindered visitors' enjoyment of beaches and lakes in places in the U.S. such as Florida,[15] California[13] Vermont,[46] and Utah.[27] Persons hoping to enjoy their vacations or days off have been kept away to the detriment of local economies. Florida, which declared a state of emergency in four counties in early July 2016, has seen beachgoers frightened away.[47] Senator Marco Rubio called the situation in Florida "a health, ecological and economic emergency."[48]

Boaters in a freshwater algal bloom

Similar blooms have become more common in Europe, with countries including France reporting them. In the summer of 2009, beaches in northern Brittany, which has a high concentration of pig, cattle and poultry farms, became covered by tonnes of potentially lethal rotting green algae. A horse being ridden along the beach collapsed and died from fumes given off by the rotting algae.[49]

The economic damage resulting from lost business has become a serious concern. According to one report in 2016, the four main economic impacts from harmful algal blooms come from damage to human health, fisheries, tourism and recreation, and the cost of monitoring and management of area where blooms appear.[50] The U.S. Environmental Protection Agency (EPA) estimates that algal blooms impact 65 percent of the country's major estuaries, with an annual cost of $2.2 billion.[34] In the U.S. there are an estimated 166 coastal dead zones.[34] Because data collection has been more difficult and limited from sources outside the U.S., most of the estimates as of 2016 have been primarily for the U.S.[50]

In the summer of 2016, major portions of Florida's Indian River Lagoon, as well as lakes and rivers in North Dakota, Minnesota, Utah, Southern California and Ohio, had posted health warnings, beach closings and swimming advisories.[51] Florida declared a state of emergency for four counties as a result of blooms. They were said to be "destroying" a number of businesses and affecting local economies, with many needing to shut down entirely.[52] With many beaches closed, hotels and restaurants suffered a drop in business. Tourist sporting activities such as fishing and boating were also affected.[53]

In port cities in Shangdong Province of eastern China, residents are no longer surprised when massive algal blooms arrive each year and inundate beaches. Prior to the Beijing Olympics in 2008, over 10,000 people were used to clear up 20,000 tons of dead algae along the beaches.[54] A 2013 bloom in China, thought to be its largest ever,[55] covered an area of 7,500 square miles,[54] followed by a similar bloom in 2015 blanketing an even larger 13,500 square miles. The blooms in China are thought to be caused by pollution from untreated agricultural and industrial discharges into rivers leading to the ocean.[56]

Fisheries industry[edit]

West coast algal bloom of 2015 which led to closing of fisheries

As early as 1976 a short-term, relatively small, dead zone off the coasts of New York and New Jersey cost commercial and recreational fisheries over $500 million.[57] In 1998 a red tide in Hong Kong killed over $10 million in high-value fish.[58]

In 2009, the economic impact for the state of Washington's coastal counties dependent on its fishing industry was estimated to be $22 million in lost revenue.[59] In 2016, the U.S. seafood industry expected future lost revenue could amount to $900 million annually.[50]

The National Oceanic and Atmospheric Administration (NOAA) has provided a few cost estimates for various blooms over the past few years:[60] $10.3 million in 2011 due to the red tide at Texas oyster landings; $2.4 million lost income by tribal commerce from 2015 fishery closures in the pacific northwest; $40 million from Washington state's loss of tourism from the same fishery closure.

Along with damage to businesses, the toll from human sickness and death results in lost wages and work days. The costs of medical treatment, investigation by health agencies through water sampling and testing, and the posting of warning signs at effected locations is also costly.[61] In 2000, one estimate by the Woods Hole Oceanographic Institution of the annual economic impact from HABs in the U.S. was up to $743,000. However, that estimate included primarily marine coastal areas with few inland or freshwater areas then a major concern, and the institute expected HABs to become "a significant and expanding threat to human health and fisheries resources throughout the United States and the world."[61]

Economic costs are estimated to rise. In June 2015, for instance, the largest known toxic HAB forced the shutdown of the west coast shellfish industry, the first time that has ever happened. One Seattle NOAA expert commented, "This is unprecedented in terms of the extent and magnitude of this harmful algal bloom and the warm water conditions we're seeing offshore...."[62] The bloom covered a range from Santa Barbara California up to Alaska.[63]

Environmental impact[edit]

Portion of a dead zone in the Gulf of Mexico

Some dinoflagellates and cyanobacteria produce toxins that can affect domestic animals and humans. Marine algal toxins include domoic acid, saxitoxin, and brevetoxin, any of which, if it accumulates in the bodies of fish or shellfish, and should not be eaten. Anatoxins, found in freshwater blue-green algae (cyanobacteria,) affect the nervous system, or if it contains microcystins or nodularin, can cause liver damage if the water is ingested.[64]

However, the environmental effects of some harmful algae are not related to their toxins but rather to the depleted oxygen in water caused by their death and decay. In addition, the blockage of sunlight by the floating algae and the physical damage to the gills of fish caused by some algae can cause fish to die.[64]

Increasing number and range[edit]

Harmful algal blooms (cyanobacterial) blooms are increasing throughout the world. Major rivers in the U.S. have seen an increase in their size and frequency. In 2015 the Ohio River had a bloom which stretched 650 miles into adjoining states and was tested as producing toxins which created problems for supplying drinking water and recreation. One official stated that its size was "unprecedented."[65] A portion of Utah's Jordan River was closed due to toxic algal bloom in 2016.[27]

Researchers have reported the growth of HABs in Europe, Africa and Australia. Those have included blooms on some of the African Great Lakes, such as Lake Victoria, the second largest freshwater lake in the world.[40] India has been reporting an increase in the number of blooms each year. The country reported having a total of 12 blooms from 1917 through 1957. From 1958 to 1997 the total rose to 38. And in the 12 years from 1998 to 2010 they reported having 80 harmful algal blooms.[66] In 1977 Hong Kong reported its first red tide. By 1987 they were getting an average of 35 per year.[58]

Global warming and pollution is causing algal blooms to form in places previously considered "impossible" or rare for them to exist, such as under the ice sheets in the Arctic,[67] in Anarctica,[68] the Himalayan Mountains,[69] the Rocky Mountains,[70] and the Sierra Nevada Mountains in California.[71]

Fish die-offs[edit]

Massive fish die-off in Brazil

Massive fish die-offs have been caused by HABs.[72] In 2016, 23 million salmon which were being farmed in Chile died from a toxic algae bloom.[73] To get rid of the dead fish, the ones fit for consumption were made into fishmeal and the rest were dumped 60 miles offshore to avoid risks to human health.[73] Environmental expert Lester Brown has written that the farming of salmon and shrimp in offshore ponds concentrates waste, which contributes to eutrophication and the creation of dead zones.[74] The economic cost of that die-off is estimated at $800 million in lost revenue with a production decline of 16 percent.[73]

Other countries have reported similar impacts, with cities such as Rio de Janeiro Brazil seeing major fish die-offs from blooms becoming a common occurrence.[75] In early 2015, Rio collected an estimated 50 tons of dead fish from the lagoon where water events in the 2016 Olympics were planned to take place.[75]

In May of 2015, researchers in Santa Cruz California witnessed a mass die-off of anchovies in the Monterey Bay due to a red tide and the high level of domoic acid it produced. The seafloor in Monterey Bay was "littered with anchovies" which experts felt could lead to the death of seabirds which were feeding on them.[76] Similar fish die-offs from toxic algae or lack of oxygen have been seen in Russia,[77] Colombia,[78] Viet Nam,[79] China,[80] Canada,[81] Turkey,[82] Indonesia,[83] and France.[84]

Mammal and bird deaths[edit]

Land animals, including livestock and pets have been affected. Dogs have died from the toxins after swimming in algal blooms.[85] Warnings have come from government agencies in the state of Ohio, which noted that many dogs and livestock deaths resulted from HAB exposure in the U.S. and other countries. They also noted in a 2003 report that during the previous 30 years, they have seen more frequent and longer-lasting harmful algal blooms."[86] It noted that in 50 countries and 27 states, there were reports of human and animal illnesses linked to algal toxins.[86] In Australia, the department of agriculture warned farmers that the toxins from a HAB had the "potential to kill large numbers of livestock very quickly."[87]

Marine mammals have also been harmed. In 2013 a red tide in southwest Florida killed a record number of Manatee.[88] Similarly, in 1999 over 65 bottlenose dolphins died during a red tide in Florida.[89]

Whales have also died in large numbers. During the period from 2005 to 2014, Argentina reported an average 65 baby whales dying which experts have linked to algal blooms. A whale expert there expects the whale population to be reduced significantly.[90] A month earlier, Alaska and British Columbia reported 18 humpback whales were found dead from what experts suspect was from HAB toxins.[91] A decade earlier off Cape Cod in the North Atlantic, at least 12 humbpack whales died from what experts suspected was also caused by toxic algae from a red tide.[92]

Birds have died after eating dead fish contaminated with toxic algae. Rotting and decaying fish are eaten by birds such as pelicans, seagulls, cormorants, and possibly marine or land mammals, which then become poisoned.[72] The nervous systems of dead birds were examined and had failed from the toxin's effect.[32] On the Oregon and Washington coast, a thousand scoters, or sea ducks, were also killed in 2009. ""This is huge," said a University professor.[93] As dying or dead birds washed up on the shore, wildlife agencies went into "an emergency crisis mode."[93]

More dead zones[edit]

Dead zone in the southern U.S.

According to NOAA, blooms can harm the environment even without producing toxins by depleting oxygen from the water when growing and while decaying after they die. Blooms can also block sunlight to organisms living beneath it. Record-breaking numbers and sizes of blooms have formed in the Pacific coast, in Lake Erie, in the Chesapeake Bay and in the Gulf of Mexico, where a number of dead zones exist.[48] In the 1960s the number of dead zones worldwide was 49, rising to over 400 by 2008.[57] In the U.S. they are especially prevalent along the east and south coasts.[57]

Various important natural habitats such as rivers, lakes and estuaries have continued to degrade and has contributed to creating more oxygen-deprived dead zones, including some in the Gulf of Mexico, the Chesapeake Bay, and Lake Erie.[94][95]

Among the largest were those in northern Europe’s Baltic Sea and the Gulf of Mexico, which affects a $2.8 billion U.S. fish industry.[40] Unfortunately, dead zones rarely recover and usually grow in size.[57] One of the few dead zones to ever recover was in the Black Sea, which returned to normal fairly quickly after the collapse of the Soviet Union in the 1990s, which led to a major reduction in fertilizer use.[57]

Potential remedies[edit]

Sensors and monitoring devices[edit]

A growing number of scientists agree that there is an urgent need to protect the public by being able to forecast harmful algal blooms.[96] One way they hope to do that is with sophisticated sensors which can help warn about potential blooms.[97] The same types of sensors can also be used by water treatment facilities to help them prepare for higher toxic levels.[96][98]

The only sensors now in use are located in the Gulf of Mexico. In 2008 similar sensors in the Gulf forewarned of an increased level of toxins which led to a shutdown of shellfish harvesting in Texas along with a recall of mussels, clams and oysters, possibly saving many lives.[96] With an increase in the size and frequency of HABs, experts state the need for significantly more sensors located around the country.[96] The same kinds of sensors can also be used to detect threats to drinking water from intentional contamination.[99]

Four federal agencies, The U.S. Environmental Protection Agency (EPA), National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the USGS are working on ways to detect and measure cyanobacteria blooms using satellite data.[100] The data may help develop early-warning indicators of cyanobacteria blooms by monitoring both local and national coverage.[101]

However, in the U.S. at least, funding for such warning devices has been shrinking, with approved funding down 45% over the last five years. According to one marine science professor, "We need it more than ever, and we’ve brought ourselves to the precipice of making great forecasts, but we can’t make it happen."[96]

Reducing chemical runoff[edit]

Soil and fertilizer runoff from a farm after heavy rains

The nitrates and phosphorus in fertilizers cause algal blooms when they run off into lakes and rivers after heavy rains. Modifications in farming methods have been suggested, such as only using fertilizer in a targeted way at the appropriate time exactly where it can do the most good for crops to reduce potential runoff.[102] A method used successfully is drip irrigation, which instead of widely dispersing fertilizers on fields, drip-irrigates plant roots through a network of tubes and emitters, leaving no traces of fertilizer to be washed away.[103] According to the OECD, drip irrigation also prevents the formation of algal blooms in reservoirs for drinking water[104] while saving up to 50% of water typically used by agriculture.[105]

A number of states in the U.S. have tried eliminating phosphates from household detergents and cleaning water treatment plants, which succeeded in reducing the amount that entered Lake Erie by 66%. However, changes in farming practices during that period increased chemical runoff, thereby offsetting the improvements.[102]

There have also been proposals to create buffer zones of foliage and wetlands to help filter out the phosphorus before it reaches water.[102] Other experts have suggested using conservation tillage, changing crop rotations, and restoring wetlands.[102] "The most important thing that can be done is to reduce agricultural runoff," according to a Great Lakes pollution expert. "Prevention is better than treatment."[102] Another expert states that it is possible for some dead zones to shrink within a year under proper management.[106]

There have been a few success stories in controlling chemicals. After Norway's lobster fishery collapsed in 1986 due to low oxygen levels, for instance, the government in neighboring Denmark took action and reduced phosphorus output by 80 percent which brought oxygen levels closer to normal.[106] Similarly, dead zones in the Black Sea and along the Danube River recovered after phosphorus applications by farmers were reduced by 60%.[106]

Research and management[edit]

Algal blooms forming and breaking up over time

In 2008, the U.S. government prepared a report on the problem, "Harmful Algal Bloom Management and Response: Assessment and Plan".[107] The report recognized the seriousness of the problem:

It is widely believed that the frequency and geographic distribution of HABs have been increasing worldwide. All U.S. coastal states have experienced HABs over the last decade, and new species have emerged in some locations that were not previously known to cause problems. HAB frequency is also thought to be increasing in freshwater systems.[107]

The report suggested among other remedies, using improved monitoring methods, trying to improve predictability, and testing new potential methods of controlling HABs.[107] Some countries surrounding the Baltic Sea, which has the world's largest dead zone, have considered using massive geoengineering options, such as forcing air into bottom layers to aerate them.[57]

Monitoring and reporting[edit]

Most countries, states and large cities have departments which will help monitor and report incidents of algal blooms. The Center for Disease Control and Prevention (CDC) in the U.S. launched the country's first algal bloom reporting system in June 2016.[108] Individual states usually have departments oriented toward health and environmental problems, such as the EPA, that will accept reports of blooms from citizens and will work with cities to test and report incidents to the media. A few examples:


  1. ^ a b c d Harmful Algal Blooms, Center for Disease Control
  2. ^ a b c Ryan, John. "Red Tide & HAB Studies in Monterey Bay", Monterey Bay Sanctuary Advisory Council Meeting, August 15, 2008
  3. ^ Black, Jacquelyn G., and Black, Laura J. Microbiology: Principles and Explorations, 8th Ed., John Wiley & Sons (2012)
  4. ^ a b c Peebles, Ernst B. "Why toxic algae blooms like Florida’s are so dangerous to people and wildlife", Huffington Post, July 20, 2016
  5. ^ a b c "Are all algal blooms harmful?", NOAA, April 28, 2016
  6. ^ a b c d e f "Neurotoxic algae bloom that shuts down Utah Lake can affect brain, liver", KUTV, July 15, 2016
  7. ^ a b "Toxic Algae Bloom Leaves 500,000 Without Drinking Water in Ohio", Ecowatch, August 3, 2014
  8. ^ a b "What you need to know about toxic algae blooms", USA Today, August 7, 2015
  9. ^ a b FAQs about red tides, Texas Parks & Wildlife Department
  10. ^ "Intense, widespread algal blooms reported in Chesapeake Bay", Science Daily, Sept. 1, 2015
  11. ^ a b "Domoic Acid Toxicity", The Marine Mammal Center
  12. ^ a b "NOAA Fisheries mobilizes to gauge unprecedented West Coast toxic algal bloom", Northwest Fisheries Science Center, June 2015
  13. ^ a b c d e f g "Summer conditions growing toxic algae blooms in two California lakes", Los Angeles Times, July 21, 2016
  14. ^ a b "Climate Change and Harmful Algal Blooms", Environmental Protection Agency (EPA)
  15. ^ a b c "Summer Heat Could Worsen Algae Blooms In Florida Waters", WLRN, July 14, 2016
  16. ^ a b c "Russian River to be closely monitored this summer to guard against harmful algae blooms", Press Democrat, June 23, 2016
  17. ^ a b c d e f Miller, G. Tyler Jr., Environmental Science, Thomas Learning (2003) pp. 355–357
  18. ^ Kozacek, Codi. "Algal Blooms Are No Accident For Florida Everglades and Estuaries", Circle of Blue, July 20, 2016
  19. ^ "Ohio plan to restore Lake Erie won’t mandate farming changes", The Columbus Dispatch, July 27, 2016
  20. ^ "Scientists eye increase in harmful algae in Chesapeake", The Baltimore Sun, May 8, 2015
  21. ^ "Too Much Nitrogen and Phosphorus Are Bad for the Bay", Chesapeake Bay Foundation, 2016
  22. ^ "Massive Nitrogen Pollution Accompanies China's Growth", Scientific American, Feb. 27, 2013
  23. ^ "On Lake Taihu, China Moves To Battle Massive Algae Blooms", Environment 360, Yale University, July 21, 2011
  24. ^ "Spreading Dead Zones and Consequences for Marine Ecosystems", Science, August 15, 2008
  25. ^ "Study: Chesapeake Bay a bigger methane generator than previously thought", Daily Press, July 19, 2016
  26. ^ "Algal blooms 'likely to flourish as temperatures climb'", Straits Times, July 20, 2016
  27. ^ a b c d e "Utah County portion of Jordan River closed due to toxic algal bloom", Daily Herald, July 21, 2016
  28. ^ Algae Blooms in fish farming, Farmed and Dangerous.org
  29. ^ "One Of The U.S.’s Top Salmon Providers Just Lost Millions Of Salmon", Climate Progress, March 10, 2016
  30. ^ "Blue algae problems persist", Marysville Online, July 13, 2016
  31. ^ "Lethal paralytic shellfish poisoning from consumption of green mussel broth, Western Samar, Philippines, August 2013", World Health Organization, Issue #2, April-June 2015
  32. ^ a b "Toxic algae blooms killing sea birds, threaten humans", KSBW, April 30, 2014
  33. ^ "Aerosolized Red-Tide Toxins (Brevetoxins) and Asthma", U.S. National Laboratory of Medicine, January 2007
  34. ^ a b c "Effects of algal blooms continue to spread throughout Wasatch Front", KSL TV, July 19, 2016
  35. ^ "People got sick at Pyramid Lake before the state reported toxic algae bloom. Could it have been avoided?", San Gabriel Valley Tribune, July 18, 2016
  36. ^ "Dog dies on Russian River, tests positive for toxic algae", Sept. 3, 2015
  37. ^ "Drinking water could be poisoned with toxic algae linked to Alzheimer’s", The Telegraph, Feb. 26, 2015
  38. ^ "The Big-Ag-Fueled Algae Bloom That Won't Leave Toledo's Water Supply Alone", Mother Jones, August 5, 2016
  39. ^ "Lake Erie’s Toxic Algae Bloom Forecast for Summer 2016", EcoWatch, June 13, 2016
  40. ^ a b c "World Stands By As Algae and Dead Zones Ruin Water", Circle of Blue, Sept. 25, 2014
  41. ^ "Algae smother Chinese lake, millions panic", NBC News, May 31, 2007
  42. ^ "In China, a Lake’s Champion Imperils Himself", New York Times, Oct. 14, 2007
  43. ^ "Algal bloom in Central China reservoir affects drinking water of 15,000", Chinaview, July 8, 2009
  44. ^ "Blue-green algal bloom chokes Murray, cuts water to farmers", The Age, March 9, 2016
  45. ^ Video interview: Dr. Alan Steinman on Algal Blooms in Lake Erie 13 min.
  46. ^ "Vt. Beaches Reopen After Algae Blooms Clear", NECN, July 15, 2016
  47. ^ "Toxic algae driving away Florida beachgoers", CNBC, July 5, 2016
  48. ^ a b "Toxic Algal Blooms Aren’t Just Florida’s Problem. And They’re On The Rise.", Huffington Post, July 7, 2016
  49. ^ "Lethal algae take over beaches in northern France", The Guardian, U.K., August 10, 2009
  50. ^ a b c "Algal bloom and its economic impact", European Commission Joint Research Centre, 2016
  51. ^ "Algae is blooming in waterways all around the country", Florida Today, July 22, 2016
  52. ^ "How Florida's Toxic Algae is Choking the Economy And The Environment", Nature World News, July 19, 2016
  53. ^ "Florida Tourism Not Seeing Green as Toxic Algae Chokes Business", NBC News, July 11, 2016
  54. ^ a b "China: Yellow Sea turns green as Qingdao beaches are covered in algae", International Business Times, July 7, 2015
  55. ^ "China hit by largest-ever algae bloom", Phys.org, July 4, 2013
  56. ^ "Slimy green algae is taking over China's beaches for an alarming reason", Business Insider, July 13, 2015
  57. ^ a b c d e f "Oceanic Dead Zones Continue to Spread", Scientific American, August 15, 2008
  58. ^ a b Brown, Lester; McGinn, Anne Platt. Vital Signs 1999-2000: The Environmental Trends that Are Shaping Our Future, Routledge (1999 pp. 198-199
  59. ^ "Assessing Algal Blooms’ Economic Impact", New York Times, November 27, 2009
  60. ^ "What is a harmful algal bloom?", NOAA
  61. ^ a b "Estimated Annual Economic Impacts from Harmful Algal Blooms (HABs) in the United States", Woods Hole Oceanographic Institution, September 2000
  62. ^ "Biggest-ever toxic algal bloom hits West Coast, shutting down shellfish industries", Oregon Live, June 16, 2015
  63. ^ "Toxic algae bloom in Pacific Ocean could be largest ever", CBS News, June 17, 2015
  64. ^ a b "Algal toxins", USGS Field Manual (1999) p. 263
  65. ^ "Toxic algae bloom now stretches 650 miles along Ohio river", The Columbus Dispatch, Oct. 3, 2015
  66. ^ "Boom in harmful algal blooms", The Hindu, Dec 20, 2010
  67. ^ "NASA mission, led by Stanford biologist, finds massive algal blooms under Arctic sea ice", Stanford News, June 7, 2012
  68. ^ "Behemoth Antarctic Algae Bloom Seen from Space", Life Science, March 7, 2012
  69. ^ "Pollution, neglect and too much love killing once idyllic Himalayan lake", The Sydney Morning Herald, Nov. 5, 2011
  70. ^ "Addressing Algal Blooms in Rocky Mountain National Park", Jordan Ramis, August 6, 2015
  71. ^ " Algae in Sierra Nevada Mountain Wilderness Areas: Potential Health Hazards", Journal of Mountain Medicine and Ecology, University of California, Davis, Fall 2009
  72. ^ a b https://www.whoi.edu/science/B/redtide/foodweb/fishkills.html "Fish Kills due to Harmful Algal Blooms"], Woods Hole Oceanographic Institute
  73. ^ a b c "23 Million Salmon Dead Due to Toxic Algal Bloom in Chile", EcoWatch, March 10, 2016
  74. ^ Brown, Lester R. Plan B 4.0: Mobilizing to Save Civilization, Earth Policy Institute, p. 227
  75. ^ a b "Brazil removes 50 tons of dead fish from Olympic waters", Aljazeera, April 21, 2015
  76. ^ "Very Toxic Algal Bloom in Monterey Bay, USA: Seafloor Littered with Dead Fish", Global Research, June 3, 2015
  77. ^ "Kamensk local authorities have hired contractors to clean up mountains of dead fish from the beaches", July 18, 2016
  78. ^ "Fish kills reported in the Palafitos", W Radio, July 17, 2016
  79. ^ "Thanh Hoa: Locals wear masks as smell from dead fish overpowering", Vietnam.net, July 19, 2016
  80. ^ "Hongze Lake Suqian great, full of dead fish breeding area", Modern Express Network, July 6, 2016
  81. ^ "Massive fish kill in Quebec's Yamaska River puzzle scientists", Digital Journal, July 4, 2016
  82. ^ "Scores of starfish wash ashore in Turkey’s northwest", Hurriyet Daily News, June 28, 2016
  83. ^ "90 Tons of Fish Die Darma Masal", Radar Cirebon, June 2, 2016
  84. ^ "Maine-et-Loire: Thousands of fish suffocated with the decline", France TV, June 18, 2016
  85. ^ "Unseasonal Toxic Algae Bloom In California Lake Kills Three Dogs", Climate Progress, Feb. 2, 2015
  86. ^ a b "Harmful Algal Blooms Can Be Deadly to Pets and Livestock", Ohio Environmental Protection Agency
  87. ^ "Blue-green algal poisoning of stock", Agriculture Victoria
  88. ^ "Red Tide Algae Bloom Kills Record Number of Manatee", Accuweather, March 13, 2013
  89. ^ "State of the Coastal Environment: Harmful Algal Blooms", NOAA
  90. ^ "Algal Blooms Linked to Largest Die-Off of Great Whales Ever Recorded", EcoWatch, Oct. 29, 2015
  91. ^ "Toxic Algae Could Be Killing Dozens of Whales", Inverse, Sept. 16, 2015
  92. ^ "Toxic algae suspected in whale death", Nature, August 4, 2003
  93. ^ a b "Foam from ocean algae bloom killing thousands of birds", Oregon Live, October 22, 2009
  94. ^ "Lake Erie Dead Zone: Don't Blame the Slime!", Live Science, January 6, 2015
  95. ^ Kozacek, Codi. "Algal Blooms Are No Accident For Florida Everglades and Estuaries", Circle of Blue, July 20, 2016
  96. ^ a b c d e "A Dreaded Forecast for Our Times: Algae, and Lots of It", New York Times, July 18, 2016
  97. ^ "Keeping Tabs on HABs: New Tools for Detecting, Monitoring, and Preventing Harmful Algal Blooms", Environmental Health Perspectives, August 1, 2014
  98. ^ "Keeping Tabs on HABs: New Tools for Detecting, Monitoring, and Preventing Harmful Algal Blooms", Environmental Health Perspectives, August 2014
  99. ^ "Water System Security and Resilience in Homeland Security Research", Environmental Protection Agency
  100. ^ "US agencies creating algal bloom early warning system", Algae Industry Magazine, April 8, 2015
  101. ^ "Remote Sensing Provides a National View of Cyanobacteria Blooms", USGS
  102. ^ a b c d e Biello, David. "Deadly Algae Are Everywhere, Thanks to Agriculture", Scientific American, August 8, 2014
  103. ^ Siegel, Seth M. Let There Be Water: Israel’s Solution for a Water-Starved World, Macmillan (2015) p. 66
  104. ^ "Israel: Innovations overcoming water scarcity", OECD Observer, April 2015
  105. ^ "How Israel survived its devastating drought", San Diego Union-Tribune, June 16, 2015
  106. ^ a b c Larsen, Janet. "Dead Zones Increasing in the World's Coastal Waters", Earth Policy Institute, June 16, 2004
  107. ^ a b c "Harmful Algal Bloom Management and Response: Assessment and Plan", Office of Science and Technology Policy, Sept. 2008
  108. ^ "CDC launches first national reporting system for harmful algal blooms and associated illnesses", CDC, June 22, 2016

External links[edit]