Title: Great Lakes
Content: Great Lakes algae blooms in particular in the warmer and shallower portions of the system such as Lake Erie, Saginaw Bay, Green Bay, and the southernmost portion of Lake Michigan. By the mid-1980s, most jurisdictions bordering the Great Lakes had controlled phosphate detergents, resulting in sharp reductions in the frequency and extent of the blooms. In 2013, news of a garbage patch of plastic pollution in the lakes was reported. Until 1970, mercury was not listed as a harmful chemical, according to the United States Federal Water Quality Administration. Within the past ten years mercury has become more apparent in

Title: Lake Winnipeg algae threat
Content: the last decade with hundreds of square kilometers of the lake covered with a thick toxic layer of blue-green algae. Local residents in surrounding communities say the blue-green algae is well known for creating deadly water conditions in prairie dugouts and have been known to even kill livestock. Commercial and aboriginal fishermen on the lake often find their nets temporarily disabled during the summer months because of the thick algae conditions. The Lake Winnipeg algae blooms are considered the worst algae problem of any large freshwater lake in the world. The LWF is a non-profit organization that was founded in

Title: Harmful algal bloom
Content: foam, scum, or mat on or just below the surface of water and can take on various colors depending on their pigments. Cyanobacteria blooms in freshwater lakes or rivers may appear bright green, often with surface streaks which looks like floating paint. 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 warm waters that have excessive nutrients. 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.

Title: Fish kill
Content: gills and an over-production of mucilage across the whole body. Lime produces similar symptoms but is also often associated with milk eyes. An algae bloom is the appearance of a large amount of algae or scum floating on the surface of a body of water. Algae blooms are a natural occurrence in nutrient-rich lakes and rivers, though sometimes increased nutrient levels leading to algae blooms are due to fertilizer or animal waste runoff. A few species of algae produce toxins, but most fish kills due to algae bloom are a result of decreased oxygen levels. When the algae die, decomposition

Title: Cyanobacteria
Content: unicellular marine cyanobacteria. Cyanobacteria growth is favored in ponds and lakes where waters are calm and have less turbulent mixing. Their life cycles are disrupted when the water naturally or artificially mixes from churning currents caused by the flowing water of streams or the churning water of fountains. For this reason blooms of cyanobacteria seldom occur in rivers unless the water is flowing slowly. Growth is also favored at higher temperatures, making increasing water temperature as a result of global warming more problematic. At higher temperatures Microcystis species are able to outcompete diatoms and green algae. This is a concern

Question: What name is given to the huge growths of algae sometimes seen in polluted lakes and rivers?
Answer: A bloom