How can algal blooms be harmful

A review of the current model predictions of how climate change could affect pelagic freshwater Cyanobacteria. Water Research , 46, Breadcrumb Home Our science Projects Algal blooms and human health. Scientific challenge Blooms of algae in freshwaters can produce potent toxins, potentially making water bodies unsafe for recreational activities and restricting their access to the public and their suitability as a source of water for drinking and irrigation.

Providing the evidence base Algae can bloom in waters that have been polluted with high levels of nutrients, such as phosphorus. Climate Change Impacts Using a continental-scale dataset of European lakes , we have examined how nutrient pollution interacts with climatic stressors, such as high temperatures, low rainfall and extreme weather events and have shown how different lake types across Europe have different sensitivities to nutrients and climatic variables Richardson et al.

Future challenges In the GloboLakes Project, we are examining satellite earth observation data to examine the distribution of harmful algal blooms in of the world's largest lakes globally and how climate, land-use and population in their catchments explain their abundance.

Principal Investigator. Laurence Carvalho. For this reason, many states are adopting the U. Many cyanobacteria blooms, like those appearing in Florida news headlines, can produce toxins cyanotoxins that cause immediate— and sometimes long-term—damage to humans and wildlife alike. Some cyanobacteria are especially toxic for children and pets. Cyanobacteria is particularly lethal for dogs that are exposed by swimming or wading in water that contains algae.

Even though a blue green algae bloom tends to die as quickly as it was produced, harmful conditions can still be present after the bloom is no longer visible.

The death process of the bloom consumes large amounts of oxygen within the waterbody, which can be harmful or lethal to birds, fish, and other aquatic animals, among other environmental stresses. The breakdown of the bloom also can cause water discoloration, drinking water contamination, and decreased invertebrate reproduction. Multiple toxic algae blooms can happen simultaneously depending on the conditions in the pond or lake.

And wind or water currents sometimes concentrate a bloom by pushing it to one area of a waterbody. Depending on the size of the lake or pond, this can create exceptionally hazardous or toxic areas.

The smaller or more shallow the pond, the more likely it will be affected by toxic algae. Not all cyanobacteria produce toxins, but nontoxic blooms can negatively impact the environment and local economies.

Unmanaged or repetitive algal blooms can contribute to decreased property values and increased HOA and community maintenance costs. Algae growth depends on weather patterns, temperature, and nutrients in the water.

Pollutants from construction runoff, fertilized yards and golf courses, road wash, stormwater runoff, pet waste, and decomposing leaves, grass clippings, and other organic materials also contribute to nutrient imbalances in the water.

Higher temperatures and increased sunlight in summer months also can encourage algae blooms, as does standing water, which is warmer than circulating water and can act like an incubator— another significant influence. Part of that expansion is due to advances in our understanding of toxic algal species, as well as our grasp on their ecological and economic cost; today, we know a diversity of harmful algae blooms occur in every state and across all seasons. Not all algal blooms are created equal.

Some just stink up lakes and ponds, but others pose a health risk or have cost coastal economies millions of dollars, according to the National Oceanic and Atmospheric Administration. Of those, several hundred species are reported to form large blooms—and nearly one-fourth of those are known to produce harmful toxins, according to the Intergovernmental Oceanographic Commission of UNESCO.

In freshwater lakes and rivers, harmful algal blooms often consist of cyanobacteria, which can produce toxins that pose a health risk to humans and wildlife. Bodies of freshwater in all 50 states. They are primarily a public health concern, as they can produce hazardous toxins—notably the neurotoxin microcystin, which destroys mammalian nerve tissue. In , a harmful blue-green algae on Lake Erie , near Toledo, Ohio led to microcystin levels in high enough concentration that officials advised half a million residents not to drink tap water for three days.

In , officials in Iowa found microcystin in the raw water supplies of 15 out of 26 public water systems tested. Cyanobacteria blooms—which form thick, green mats—can also wage ecological harm by making it difficult for aquatic life to thrive. And its economic costs are well-documented: Local governments need to treat cyanobacteria-contaminated drinking water, and regional tourism often takes a hit when people are kept from fishing, swimming, boating, and beaching.

Red tides also pose a danger to humans and marine life. In people, red tide can cause respiratory illness and irritate the eyes. It can be lethal for marine life. Red tides made up of diatoms, a common group of algae, like Pseudonitzschia can produce the neurotoxin domoic acid, which can cause seizures in birds and some other vertebrates. Domoic acid can also accumulate in shellfish, sardines and anchovies and can cause serious injury or death in sea lions, otters, birds, and humans that eat them in the summer of , officials in Washington, Oregon, and California closed shellfish fisheries due to high concentrations of domoic acid—costing coastal communities and fisheries tens of millions of dollars.