Lake Winnipeg algae threat

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Lake Winnipeg covered in algae blooms. (July 2007) AlgaeLW.jpg
Lake Winnipeg covered in algae blooms. (July 2007)

Lake Winnipeg has experienced excessive algae blooms since the 1990s. [1] The lake's toxic blue-green algae has led to a deterioration of water quality, posing hazards to both human and animal ecosystems. The blooms are caused by high concentrations of nitrogen and phosphorus from fertilizer runoff and sewage draining into the lake via rivers and surface runoff.

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By 2006, Lake Winnipeg's algae blooms were considered to be the worst algae problem of any large freshwater lake in the world, according to Canadian Geographic. [2] In 2013, Lake Winnipeg was declared the most threatened lake in the world by the Global Nature Fund, due to excessive levels of phosphorus. Attempts to decrease the levels have been unsuccessful. In 2017, it was reported that a five-year effort removed less than 1% of the phosphorus. [3]

Very high levels of the algae toxin microcystin closed Victoria Beach off from the public in the summer of 2003. [4] Grand Beach and other settlements along the lake are often closed during summer months due to E. coli and algae-toxin-related threats. Immense algae blooms covering hundreds of square kilometers have appeared in the northern part of Lake Winnipeg since the 2010s.

Social and economic impacts

Damage to Lake Winnipeg's ecological balance has had adverse economical effects for the area's $100 million a year tourism industry and $25 million a year fishing industry. [5] The toxins that blue-green algae release destroy freshwater ecosystems and are dangerous for a wide variety of aquatic and terrestrial species, including humans. Deadly water conditions in prairie dugouts have killed livestock. [4] Commercial and indigenous fishermen on the lake often find their nets disabled during the summer months due to the thick algae conditions.

Watershed and water supply problems

Lake Winnipeg ranks as the 11th largest freshwater lake in the world by surface area. The lake consists of three well-defined regions, the larger North Basin, the smaller South Basin, and the connecting body of water defined as the "Narrows", all of which are greatly affected by algae blooms. The surrounding watershed's drainage basin is roughly forty times larger than the lake's surface area. This ratio is higher than any other major lake in the world, making Lake Winnipeg more susceptible to excessive nutrient levels. Because the lake holds a considerably small volume of water, the water quality is diminished by man made structures and high nutrient loading. [6]
Eutrophication entry points in Lake Winnipeg include:

Water outflow points in Lake Winnipeg include:

The Red River accounts for roughly 7,716 tonnes of phosphorus draining into Lake Winnipeg per year. [5] Approximately 2,500 tonnes of phosphorus flow out of the lake every year through the Nelson River. [7] It is estimated that incoming phosphorus levels are doubled by agriculture and waste waters from the northern United States. The Saskatchewan River carries phosphorus from Alberta and Saskatchewan into the northwestern part of the lake. The Winnipeg River also nutrient loads the lake from Minnesota and Ontario. The nearby City of Winnipeg does not remove nitrogen and phosphorus from the majority of its wastewater (though upgrades to its sewage treatment plants were underway as of 2017 [8] ), and these nutrients flow directly into Lake Winnipeg. Due to the washing and filtration techniques used by year-round and seasonal inhabitants along Lake Winnipeg, phosphorus-enriched soapy water can seep into the lake. [5]

Hydroelectricity

A large hydroelectric dam in Grand Rapids, Manitoba, controls the powerful Saskatchewan River. The river currents rapidly catch runoff from much of the Canadian prairies, which then flows through a narrow channel eventually spilling into the north side of Lake Winnipeg. Manitoba Hydro operates numerous dams throughout Manitoba that directly affect Lake Winnipeg's water levels and flow rate. Hydroelectric operations along Lake Winnipeg produce hundreds of millions of dollars in revenue every year for Manitoba Hydro. [9] Pressure from provincial authorities and the media has prompted Manitoba Hydro to donate more than $1.35 million over a six-year span to help researchers tackle the constant biological and water quality changes in Lake Winnipeg. [10]

Chemical and biological problems

Environment Canada reports that the amount of nitrogen and phosphorus in Lake Winnipeg has increased dramatically since the 1990's The causes are a massive increase in the use of agricultural fertilizer, burning of fossil fuels, development of large urban populations, and an upsurge in land clearing and deforestation. [11] Nitrogen and phosphorus loading from human activity has accelerated eutrophication of certain rivers, lakes, and wetlands, resulting in loss of habitat, changes in biodiversity and, in some cases, loss of recreational potential. [11] Lake Winnipeg suffers from the rapid absorption of the elements phosphorus, nitrogen, and carbon. Eutrophication processes fuel the growth of blue-green algae, also known by its more correct scientific name cyanobacteria. These bacteria normally appear green in color and can turn blue when the algae (bacteria) blooms are dying. As an algae bloom dies, the microscopic cells break down, releasing toxins in the surrounding water. Once released, some toxins can linger for more than three months until sunlight and the natural population of healthy green algae in the lake degrade them. [12] Cyanobacteria typically thrive off of phosphorus when Lake Winnipeg's summer temperatures are hot and wind speeds are relatively low. Blue-green algae blooms frequently persist for several months in Lake Winnipeg until colder temperatures, currents, and changes in the seasonal weather can filter them out. The cyanobacteria's decomposition process consumes oxygen at such a high rate that this can actually suffocate Lake Winnipeg's native walleye fish species and other aquatic life. Although small amounts of blue-green algae occur naturally in Lake Winnipeg, there is no conclusive evidence of what normal levels may be. Satellite images show that blooms are occurring more frequently and are covering more surface area of the lake. [7] The Lake Winnipeg algae crisis has grown to such a large scale that the blooms can be seen from outer space.

Related Research Articles

<span class="mw-page-title-main">Algal bloom</span> Spread of planktonic algae in water

An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water 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.

<span class="mw-page-title-main">Eutrophication</span> Phenomenon where nutrients accumulate in water bodies

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 oxygen of water. Eutrophication may occur naturally or as a result of human actions. Manmade, or cultural, eutrophication occurs when sewage, industrial wastewater, fertilizer runoff, and other nutrient sources are released into the environment. Such nutrient pollution usually causes algal blooms and bacterial growth, resulting in the depletion of dissolved oxygen in water and causing substantial environmental degradation.

<span class="mw-page-title-main">Lake Okeechobee</span> Natural freshwater lake in Florida, United States

Lake Okeechobee is the largest freshwater lake in the U.S. state of Florida. It is the eighth-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.

<span class="mw-page-title-main">Microcystin</span> Cyanotoxins produced by blue-green algae

Microcystins—or cyanoginosins—are a class of toxins produced by certain freshwater cyanobacteria, commonly known as blue-green algae. Over 250 different microcystins have been discovered so far, of which microcystin-LR is the most common. Chemically they are cyclic heptapeptides produced through nonribosomal peptide synthases.

<span class="mw-page-title-main">Dead zone (ecology)</span> Low-oxygen areas in coastal zones and lakes caused by eutrophication

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 ml 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.

<span class="mw-page-title-main">Cyanotoxin</span> Toxin produced by cyanobacteria

Cyanotoxins are toxins produced by cyanobacteria. Cyanobacteria are found almost everywhere, but particularly in lakes and in the ocean where, under high concentration of phosphorus conditions, they reproduce exponentially to form blooms. Blooming cyanobacteria can produce cyanotoxins in such concentrations that they can poison and even kill animals and humans. Cyanotoxins can also accumulate in other animals such as fish and shellfish, and cause poisonings such as shellfish poisoning.

<i>Aphanizomenon flos-aquae</i> Species of bacterium

Aphanizomenon flos-aquae is a diverse group of cyanobacteria with both toxic and non-toxic strains found in brackish and freshwater environments globally, including the Baltic Sea and the Great Lakes. Recent genome sequencing efforts have identified 18 distinct varieties of Aphanizomenon flos-aquae, revealing its genetic complexity.

<span class="mw-page-title-main">Lagoa das Sete Cidades</span> Crater lake in Azores, Portugal

Lagoa das Sete Cidades is a twin lake situated in the crater of a dormant volcano on the Portuguese archipelago of the Azores. It consists of two small, ecologically different lakes connected by a narrow strait, which is crossed by a bridge. The volcano is located on the western third of the island of São Miguel. The Lagoa das Sete Cidades part of a natural landscape of communitarian interest: it is the largest body of water in the region and one of the most important freshwater resources in the archipelago.

The microbial food web refers to the combined trophic interactions among microbes in aquatic environments. These microbes include viruses, bacteria, algae, heterotrophic protists. In aquatic ecosystems, microbial food webs are essential because they form the basis for the cycling of nutrients and energy. These webs are vital to the stability and production of ecosystems in a variety of aquatic environments, including lakes, rivers, and oceans. By converting dissolved organic carbon (DOC) and other nutrients into biomass that larger organisms may eat, microbial food webs maintain higher trophic levels. Thus, these webs are crucial for energy flow and nutrient cycling in both freshwater and marine 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.

<span class="mw-page-title-main">Trophic state index</span> Measure of the ability of water to sustain biological productivity

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.

<span class="mw-page-title-main">Harmful algal bloom</span> Population explosion of organisms that can kill marine life

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, water deoxygenation, 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".

An Olszewski tube is a pipe designed to bring oxygen-poor water from the bottom of a lake to the top. This tube was first proposed by a Polish limnologist named Przemysław Olszewski in 1961 and helps combat the negative effects of eutrophication, high nutrient content, in lakes. The basic concept behind the Olszewski tube is the reduction of nutrient concentration and destratification; the more specific goal is hypolimnetic withdrawal.

<span class="mw-page-title-main">Nutrient pollution</span> Contamination of water by excessive inputs of nutrients

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.

Seston refers to the particles suspended in bodies of water, such as oceans, lakes, and rivers. Small particles of seston may be formed by the breaking down of larger particles amidst the crashing of waves, mixing of water currents, or slow disintegration. The organic constituents of seston include plankton and detritus from decomposing organisms; the inorganic components of seston are of mineral origin, essentially particles of mud suspended in the water column.

<i>Microcystis</i> Genus of bacteria

Microcystis is a genus of freshwater cyanobacteria that includes the harmful algal bloom-forming Microcystis aeruginosa. Many members of a Microcystis community can produce neurotoxins and hepatotoxins, such as microcystin and cyanopeptolin. Communities are often a mix of toxin-producing and nonproducing isolates.

Raphidiopsis raciborskii is a freshwater cyanobacterium.

Freshwater phytoplankton is the phytoplankton occurring in freshwater ecosystems. It can be distinguished between limnoplankton, heleoplankton, and potamoplankton. They differ in size as the environment around them changes. They are affected negatively by the change in salinity in the water.

The Namao is a ship ported in Gimli, Manitoba, Canada, whose purpose is to conduct research on Lake Winnipeg. It was originally built for the Canadian Coast Guard (CCG) but was eventually sold to the Lake Winnipeg Research Consortium (LWRC) who converted it to a Lake Winnipeg research vessel. Scientists using the Namao to research the environmental issues concerning the lake, for example the increasing eutrophication of the lake and the impact of invasive species. Using the Namao, the LWRC integrates education and community outreach into their work to promote sustainable living and development focussed on the youth in local communities surrounding Lake Winnipeg who are affected most by the changing dynamics of the lake.

Lake 226 is one lake in Canada's Experimental Lakes Area (ELA) in Ontario. The ELA is a freshwater and fisheries research facility that operated these experiments alongside Fisheries and Oceans Canada and Environment Canada. In 1968 this area in northwest Ontario was set aside for limnological research, aiming to study the watershed of the 58 small lakes in this area. The ELA projects began as a response to the claim that carbon was the limiting agent causing eutrophication of lakes rather than phosphorus, and that monitoring phosphorus in the water would be a waste of money. This claim was made by soap and detergent companies, as these products do not biodegrade and can cause buildup of phosphates in water supplies that lead to eutrophication. The theory that carbon was the limiting agent was quickly debunked by the ELA Lake 227 experiment that began in 1969, which found that carbon could be drawn from the atmosphere to remain proportional to the input of phosphorus in the water. Experimental Lake 226 was then created to test phosphorus' impact on eutrophication by itself.

References

  1. ↑ Macdonald, Nancy (August 20, 2009). "Canada's sickest lake". Maclean's. Archived from the original on 2009-08-28.
  2. ↑ Casey, Allan (2006). "Forgotten lake". Canadian Geographic. Archived from the original on 21 November 2010. Retrieved 25 March 2021.
  3. ↑ MacLean, Cameron (2017). "5-year fight removes less than 1% of phosphorus from Lake Winnipeg basin". cbc.ca.
  4. 1 2 CBC.ca. (2011). Annual check-up. Retrieved from http://www.cbc.ca/manitoba/features/lakewinnipeg/checkup.html Archived 2010-08-22 at the Wayback Machine
  5. 1 2 3 Halter, Dr. Reese. (2007). saving lake winnipeg. Lu & Stoot LLC, (1) Retrieved from "Archived copy" (PDF). Archived from the original (PDF) on 2011-02-06. Retrieved 2011-02-02.{{cite web}}: CS1 maint: archived copy as title (link)
  6. ↑ LWF. (2011). Challenges Lake Winnipeg faces four types of often-interrelated problems. Retrieved from "Challenges « Lake Winnipeg Foundation". Archived from the original on 2011-07-27. Retrieved 2011-02-02.
  7. 1 2 LWF. (2011). Facts about Lake Winnipeg. Retrieved from "Facts « Lake Winnipeg Foundation". Archived from the original on 2011-07-27. Retrieved 2011-02-02.
  8. ↑ Department, City of Winnipeg: Water and Waste. "Funding - Winnipeg's Sewage Treatment Program Upgrades - Sewage - Water and Waste - City of Winnipeg". www.winnipeg.ca. Retrieved 2017-05-15.
  9. ↑ Manitoba Wildlands. (2005). The Hydro Province: Manitoba's Hydroelectric Complex.(2-16). Retrieved from http://manitobawildlands.org/pdfs/HydroProvince.pdf Archived 2022-10-23 at the Wayback Machine
  10. ↑ Brennan, Bob. (2011). MB Hydro Commits Funds for Lake Winnipeg Research. Water Canada Magazine. (1). Retrieved from http://watercanada.net/2011/mb-hydro-commits-funds-for-lake-winnipeg-research/ Archived 2011-07-24 at the Wayback Machine
  11. 1 2 P.A. Chambers, M. Guy, E. Roberts, M.N. Charlton, R. Kent, C. Gagnon, G. Grove, N. Foster, C. DeKimpe and M. Giddings. (2008). Threats to Sources of Drinking Water and Aquatic Ecosystem Health in Canada. Website of Environment Canada, archived version at the Wayback Machine
  12. ↑ The state of Queensland.(2010). Department of Environment and Resource Management: blue-green algae. Retrieved from "Blue-green algae (Department of Environment and Resource Management)". Archived from the original on 2011-03-14. Retrieved 2011-02-02.
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