An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. Algal bloom commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest.
Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of microorganisms that may deplete the water of oxygen. Although eutrophication is a natural process, manmade or cultural eutrophication is far more common and is a rapid process caused by a variety of polluting inputs including poorly treated sewage, industrial wastewater, and fertilizer runoff. Such nutrient pollution usually causes algal blooms and bacterial growth, resulting in the depletion of dissolved oxygen in water and causing substantial environmental degradation.
Lake Washington is a large freshwater lake adjacent to the city of Seattle, Washington, United States. It is the largest lake in King County and the second largest natural lake in the state of Washington, after Lake Chelan. It borders the cities of Seattle on the west, Bellevue and Kirkland on the east, Renton on the south, and Kenmore on the north, and encloses Mercer Island. The lake is fed by the Sammamish River at its north end and the Cedar River at its south.
Water pollution is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution is either surface water pollution or groundwater pollution. This form of pollution can lead to many problems, such as the degradation of aquatic ecosystems or spreading water-borne diseases when people use polluted water for drinking or irrigation. Another problem is that water pollution reduces the ecosystem services that the water resource would otherwise provide.
Lake Okeechobee is the largest freshwater lake in the U.S. state of Florida. It is the tenth-largest natural freshwater lake among the 50 states of the United States and the second-largest natural freshwater lake contained entirely within the contiguous 48 states, after Lake Michigan.
Dead zones are hypoxic (low-oxygen) areas in the world's oceans and large lakes. Hypoxia occurs when dissolved oxygen (DO) concentration falls to or below 2 mg of O2/liter. When a body of water experiences hypoxic conditions, aquatic flora and fauna begin to change behavior in order to reach sections of water with higher oxygen levels. Once DO declines below 0.5 ml O2/liter in a body of water, mass mortality occurs. With such a low concentration of DO, these bodies of water fail to support the aquatic life living there. Historically, many of these sites were naturally occurring. However, in the 1970s, oceanographers began noting increased instances and expanses of dead zones. These occur near inhabited coastlines, where aquatic life is most concentrated.
Kukkarahalli Lake also called Kukkarhalli Kere, located in the heart of the Mysore city, adjoins the Manasgangotri, the Kalamandir (Rangyana) and the Central Food Technological Research Institute (CFTRI) campus. It provides lung-space to the city. Mummadi Krishnaraja Wodeyar (1794–1868) of the Mysore dynasty was responsible for getting the lake created, in the year 1864, to provide water for irrigation to about 4000 ha of land outside the city. The Lake also used to be a source of water supply to the city of Mysore but over the years, sewage and excessive land encroachments and blockage of water flow sources almost led to the eutrophication of the lake. The University of Mysore and the citizen forums of Mysore continue to make efforts to preserve the lake by implementing several remedial measures. There is a 3.5-km walkway on the periphery of the lake with shaded stone benches for visitors to sit, relax and enjoy the scenic serenity of the lake.
Bioswales are channels designed to concentrate and convey stormwater runoff while removing debris and pollution. Bioswales can also be beneficial in recharging groundwater.
Lake Apopka is the fourth largest lake in the U.S. state of Florida. It is located 15 miles (24 km) northwest of Orlando, mostly within the bounds of Orange County, although the western part is in Lake County. Fed by a natural spring, rainfall and stormwater runoff, water from Lake Apopka flows through the Apopka-Beauclair Canal and into Lakes Beauclair and Dora. From Lake Dora, water flows into Lake Eustis, then into Lake Griffin and then northward into the Ocklawaha River, which flows into the St. Johns River. Multiple parks or nature trails are present around the lake including Magnolia Park, Lake Apopka Wildlife Drive, Ferndale Preserve, Oakland Nature Preserve, Dr. Bradford Memorial Park, and Newton Park, named for A. B. Newton.
Nonpoint source (NPS) pollution refers to diffuse contamination of water or air that does not originate from a single discrete source. This type of pollution is often the cumulative effect of small amounts of contaminants gathered from a large area. It is in contrast to point source pollution which results from a single source. Nonpoint source pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage, or hydrological modification where tracing pollution back to a single source is difficult. Nonpoint source water pollution affects a water body from sources such as polluted runoff from agricultural areas draining into a river, or wind-borne debris blowing out to sea. Nonpoint source air pollution affects air quality, from sources such as smokestacks or car tailpipes. Although these pollutants have originated from a point source, the long-range transport ability and multiple sources of the pollutant make it a nonpoint source of pollution; if the discharges were to occur to a body of water or into the atmosphere at a single location, the pollution would be single-point.
The phosphorus cycle is the biogeochemical cycle that involves the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus, because phosphorus and phosphorus-based materials do not enter the gaseous phase readily. The production of phosphine gas occurs in isolated and specific conditions. Therefore, the phosphorus cycle is primarily viewed through terrestrial and aquatic ecosystems.
Monomictic lakes are holomictic lakes that mix from top to bottom during one mixing period each year. Monomictic lakes may be subdivided into cold and warm types.
The Trophic State Index (TSI) is a classification system designed to rate water bodies based on the amount of biological productivity they sustain. Although the term "trophic index" is commonly applied to lakes, any surface water body may be indexed.
A harmful algal bloom (HAB), or excessive algae growth, is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, mechanical damage to other organisms, or by other means. HABs are sometimes defined as only those algal blooms that produce toxins, and sometimes as any algal bloom that can result in severely lower oxygen levels in natural waters, killing organisms in marine or fresh waters. Blooms can last from a few days to many months. After the bloom dies, the microbes that decompose the dead algae use up more of the oxygen, generating a "dead zone" which can cause fish die-offs. When these zones cover a large area for an extended period of time, neither fish nor plants are able to survive. Harmful algal blooms in marine environments are often called "red tides".
Urban runoff is surface runoff of rainwater, landscape irrigation, and car washing created by urbanization. Impervious surfaces are constructed during land development. During rain, storms, and other precipitation events, these surfaces, along with rooftops, carry polluted stormwater to storm drains, instead of allowing the water to percolate through soil. This causes lowering of the water table and flooding since the amount of water that remains on the surface is greater. Most municipal storm sewer systems discharge untreated stormwater to streams, rivers, and bays. This excess water can also make its way into people's properties through basement backups and seepage through building wall and floors.
Nutrient pollution, a form of water pollution, refers to contamination by excessive inputs of nutrients. It is a primary cause of eutrophication of surface waters, in which excess nutrients, usually nitrogen or phosphorus, stimulate algal growth. Sources of nutrient pollution include surface runoff from farm fields and pastures, discharges from septic tanks and feedlots, and emissions from combustion. Raw sewage is a large contributor to cultural eutrophication since sewage is high in nutrients. Releasing raw sewage into a large water body is referred to as sewage dumping, and still occurs all over the world. Excess reactive nitrogen compounds in the environment are associated with many large-scale environmental concerns. These include eutrophication of surface waters, harmful algal blooms, hypoxia, acid rain, nitrogen saturation in forests, and climate change.
Filter strips, also referred to as buffer strips, are small, edge-of-field tracts of vegetated land that are used to reduce the contamination of surface water. They are primarily used in agriculture to control non-point source pollution, however, they may also be used to reduce sediment in storm water runoff from construction sites. There are several types of filter strips including vegetative filter strips, forested riparian buffers, and wind buffers. In agriculture, they are highly effective in reducing the concentration of nitrogen (N) and phosphorus (P) in runoff into surface water and are also effective in reducing sediment erosion and removing pesticides. This helps to prevent eutrophication and associated fishkills and loss of biodiversity. The use of filter strips is very common in developed countries and is required by law in some areas. The implementation and maintenance of filter strips is inexpensive and their use has been shown to be cost effective.
Phoslock is the commercial name for a bentonite clay in which the sodium and/or calcium ions are exchanged for lanthanum. The lanthanum contained within Phoslock reacts with phosphate to form an inert mineral known as rhabdophane. Phoslock is used in lake restoration projects to remove excess phosphorus from aquatic systems, thereby improving water quality and inducing biological recovery in impaired freshwater systems.
Phosphates in detergent refers to the use of phosphates as an ingredient in a detergent product. The advantage of using phosphates in a consumer laundry detergent or dishwashing detergent is that they make detergents more efficient by chelating calcium and magnesium ions. The disadvantage of using phosphates is that they remain in wastewater and eventually make their way to a natural body of water. While phosphates are low toxicity, they instead cause nutrient pollution and feed the algae. This leads to eutrophication and harmful algal bloom.
Lake Killarney is a small lake in New Zealand's South Island. It is in Tākaka just off State Highway 60. Previously used for swimming, it is now polluted due to nutrient runoff. Efforts are underway to improve water quality.
