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Granite Canal Hydroelectric Generating Station

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The Granite Canal Hydroelectric Generating Station is a component of the Newfoundland and Labrador Hydro Corporation's Bay d’Espoir Hydro Electric Development system. The generating station has a rated capacity of 40 MW with an annual average energy production of 224 gigawatt hours (GWh). The generating unit at Granite Canal utilizes approximately 37 metres of head with a rated plant flow of 122.4 cubic metres per second. The unit is equipped with a Kaplan turbine and was first synchronized on May 26, 2003.

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25-462: A fish habitat compensation system was included in this development to ensure any aquatic habitat loss was avoided, reduced or replaced. A Fish Habitat Compensation Agreement was signed with Fisheries and Oceans Canada to ensure proper construction, utilization and long term viability of the facility. 48°11′24.30″N 56°48′29.99″W  /  48.1900833°N 56.8083306°W  / 48.1900833; -56.8083306 This article about

50-946: A building or structure in Newfoundland is a stub . You can help Misplaced Pages by expanding it . This article about a hydroelectric power plant is a stub . You can help Misplaced Pages by expanding it . This article about a Canadian power station is a stub . You can help Misplaced Pages by expanding it . Aquatic ecosystem An aquatic ecosystem is an ecosystem found in and around a body of water , in contrast to land-based terrestrial ecosystems . Aquatic ecosystems contain communities of organisms — aquatic life —that are dependent on each other and on their environment. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems . Freshwater ecosystems may be lentic (slow moving water, including pools , ponds , and lakes ); lotic (faster moving water, for example streams and rivers ); and wetlands (areas where

75-481: A multiple-group design, periods of time using a time-trend design, or groups and time using a mixed design. The study by John Snow regarding a cholera outbreak in London is considered the first ecological study to solve a health issue. He used a map of deaths from cholera to determine that the source of the cholera was a pump on Broad Street. He had the pump handle removed in 1854 and people stopped dying there. It

100-1195: A result of physical, chemical or biological alterations to the environment. Physical alterations include changes in water temperature, water flow and light availability. Chemical alterations include changes in the loading rates of biostimulatory nutrients, oxygen-consuming materials, and toxins. Biological alterations include over-harvesting of commercial species and the introduction of exotic species. Human populations can impose excessive stresses on aquatic ecosystems. Climate change driven by anthropogenic activities can harm aquatic ecosystems by disrupting current distribution patterns of plants and animals. It has negatively impacted deep sea biodiversity, coastal fish diversity, crustaceans, coral reefs, and other biotic components of these ecosystems. Human-made aquatic ecosystems, such as ditches, aquaculture ponds, and irrigation channels, may also cause harm to naturally occurring ecosystems by trading off biodiversity with their intended purposes. For instance, ditches are primarily used for drainage, but their presence also negatively affects biodiversity. There are many examples of excessive stresses with negative consequences. The environmental history of

125-516: A whole appear to be risk reduction factors for many types of cancer. Temporal changes in Japan in the types of cancer common in Western developed countries have been linked to the nutrition transition to the Western diet. An important advancement in the understanding of risk-modifying factors for cancer was made by examining maps of cancer mortality rates. The map of colon cancer mortality rates in

150-504: Is crucial that aquatic ecosystems are reliably self-maintained, as they also provide habitats for species that reside in them. In addition to environmental functions, aquatic ecosystems are also used for human recreation, and are very important to the tourism industry, especially in coastal regions. They are also used for religious purposes, such as the worshipping of the Jordan River by Christians, and educational purposes, such as

175-478: Is fatal to many kinds of anaerobic bacteria. Nutrient levels are important in controlling the abundance of many species of algae. The relative abundance of nitrogen and phosphorus can in effect determine which species of algae come to dominate. Algae are a very important source of food for aquatic life, but at the same time, if they become over-abundant, they can cause declines in fish when they decay. Similar over-abundance of algae in coastal environments such as

200-727: The Great Lakes of North America illustrates this problem, particularly how multiple stresses, such as water pollution , over-harvesting and invasive species can combine. The Norfolk Broadlands in England illustrate similar decline with pollution and invasive species. Lake Pontchartrain along the Gulf of Mexico illustrates the negative effects of different stresses including levee construction, logging of swamps, invasive species and salt water intrusion . Ecological study In epidemiology , ecological studies are used to understand

225-445: The Gulf of Mexico produces, upon decay, a hypoxic region of water known as a dead zone . The salinity of the water body is also a determining factor in the kinds of species found in the water body. Organisms in marine ecosystems tolerate salinity, while many freshwater organisms are intolerant of salt. The degree of salinity in an estuary or delta is an important control upon the type of wetland (fresh, intermediate, or brackish), and

250-721: The United States was used by the brothers Cedric and Frank C. Garland to propose the hypothesis that solar ultraviolet B (UVB) radiation , through vitamin D production, reduced the risk of cancer (the UVB-vitamin D-cancer hypothesis). Since then many ecological studies have been performed relating the reduction of incidence or mortality rates of over 20 types of cancer to higher solar UVB doses. Links between diet and Alzheimer's disease have been studied using both geographical and temporal ecological studies. The first paper linking diet to risk of Alzheimer's disease

275-450: The associated animal species. Dams built upstream may reduce spring flooding, and reduce sediment accretion, and may therefore lead to saltwater intrusion in coastal wetlands. Freshwater used for irrigation purposes often absorbs levels of salt that are harmful to freshwater organisms. The health of an aquatic ecosystem is degraded when the ecosystem's ability to absorb a stress has been exceeded. A stress on an aquatic ecosystem can be

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300-429: The important abiotic environmental factors of aquatic ecosystems include substrate type, water depth, nutrient levels, temperature, salinity, and flow. It is often difficult to determine the relative importance of these factors without rather large experiments. There may be complicated feedback loops. For example, sediment may determine the presence of aquatic plants, but aquatic plants may also trap sediment, and add to

325-422: The organic compounds in their bodies as energy sources and as raw materials to create their own biomass . Euryhaline organisms are salt tolerant and can survive in marine ecosystems, while stenohaline or salt intolerant species can only live in freshwater environments. An ecosystem is composed of biotic communities that are structured by biological interactions and abiotic environmental factors. Some of

350-410: The other hand, details of outcome and exposure can be generalized to the population being studied. Examples of such studies include investigating associations between units of grouped data, such as electoral wards, regions, or even whole countries. Generally, three different designs can be used to conduct ecological studies depending on the situation. Such studies may compare populations or groups using

375-407: The relationship between outcome and exposure at a population level, where 'population' represents a group of individuals with a shared characteristic such as geography, ethnicity, socio-economic status of employment. What differentiates ecological studies from other studies is that the unit analysis being studied is the group, therefore inferences cannot be made about individual study participants. On

400-476: The relative importance of competition, mutualism or predation. There are a growing number of cases where predation by coastal herbivores including snails, geese and mammals appears to be a dominant biotic factor. Autotrophic organisms are producers that generate organic compounds from inorganic material. Algae use solar energy to generate biomass from carbon dioxide and are possibly the most important autotrophic organisms in aquatic environments. The more shallow

425-500: The risk of type A influenza by two-thirds. Ecological studies are particularly useful for generating hypotheses since they can use existing data sets and rapidly test the hypothesis. The advantages of the ecological studies include the large number of people that can be included in the study and the large number of risk-modifying factors that can be examined. The term " ecological fallacy " means that risk-associations apparent between different groups of people may not accurately reflect

450-857: The river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen , which supports greater biodiversity than the slow-moving water of pools. These distinctions form the basis for the division of rivers into upland and lowland rivers. Aquatic ecosystems perform many important environmental functions. For example, they recycle nutrients , purify water, attenuate floods, recharge ground water and provide habitats for wildlife. The biota of an aquatic ecosystem contribute to its self-purification, most notably microorganisms, phytoplankton, higher plants, invertebrates, fish, bacteria, protists, aquatic fungi, and more. These organisms are actively involved in multiple self-purification processes, including organic matter destruction and water filtration. It

475-468: The sediment through peat. The amount of dissolved oxygen in a water body is frequently the key substance in determining the extent and kinds of organic life in the water body. Fish need dissolved oxygen to survive, although their tolerance to low oxygen varies among species; in extreme cases of low oxygen, some fish even resort to air gulping. Plants often have to produce aerenchyma , while the shape and size of leaves may also be altered. Conversely, oxygen

500-559: The soil is saturated or inundated for at least part of the time). River ecosystems are flowing waters that drain the landscape, and include the biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts. River ecosystems are part of larger watershed networks or catchments, where smaller headwater streams drain into mid-size streams, which progressively drain into larger river networks. The major zones in river ecosystems are determined by

525-553: The usage of lakes for ecological study . The biotic characteristics are mainly determined by the organisms that occur. For example, wetland plants may produce dense canopies that cover large areas of sediment—or snails or geese may graze the vegetation leaving large mud flats. Aquatic environments have relatively low oxygen levels, forcing adaptation by the organisms found there. For example, many wetland plants must produce aerenchyma to carry oxygen to roots. Other biotic characteristics are more subtle and difficult to measure, such as

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550-743: The water, the greater the biomass contribution from rooted and floating vascular plants. These two sources combine to produce the extraordinary production of estuaries and wetlands, as this autotrophic biomass is converted into fish, birds, amphibians and other aquatic species. Chemosynthetic bacteria are found in benthic marine ecosystems. These organisms are able to feed on hydrogen sulfide in water that comes from volcanic vents . Great concentrations of animals that feed on these bacteria are found around volcanic vents. For example, there are giant tube worms ( Riftia pachyptila ) 1.5 m in length and clams ( Calyptogena magnifica ) 30 cm long. Heterotrophic organisms consume autotrophic organisms and use

575-420: Was a multi-country ecological study published in 1997. It used prevalence of Alzheimer's disease in 11 countries along with dietary supply factors, finding that total fat and total energy (caloric) supply were strongly correlated with prevalence, while fish and cereals/grains were inversely correlated (i.e., protective). Diet is now considered an important risk-modifying factor for Alzheimer's disease. Recently it

600-566: Was only when Robert Koch discovered bacteria years later that the mechanism of cholera transmission was understood. Dietary risk factors for cancer have also been studied using both geographical and temporal ecological studies. Multi-country ecological studies of cancer incidence and mortality rates with respect to national diets have shown that some dietary factors such as animal products (meat, milk, fish and eggs), added sweeteners/sugar, and some fats appear to be risk factors for many types of cancer, while cereals/grains and vegetable products as

625-603: Was reported that the rapid rise of Alzheimer's disease in Japan between 1985 and 2007 was likely due to the nutrition transition from the traditional Japanese diet to the Western diet. Another example of the use of temporal ecological studies relates to influenza . John Cannell and associates hypothesized that the seasonality of influenza was largely driven by seasonal variations in solar UVB doses and calcidiol levels. A randomized controlled trial involving Japanese school children found that taking 1000 IU per day vitamin D3 reduced

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