Introduction: In this lab we will be testing bodies of freshwater. We will be determining the quality of the water based on multiple factors including nitrates, phosphates, pH levels, and dissolved oxygen levels. All of these factors must be in appropriate ranges for the ecosystem to be healthy.
Literature Review: There are many different elements and chemicals that can both positively and negatively affect freshwater ecosystems. Many different factors play into the survivability of a lake, pond, river, or other freshwater environment. If all of the different factors are not balanced correctly, the fish in that particular environment have a much lower chance at survival. One factor that affects the survival of fish in a freshwater ecosystem
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Although nitrates do not have a direct effect on aquatic organisms, in excess they can create conditions, which make it difficult for aquatic creatures to survive. Algae and other aquatic plants use nitrates as a source of food so if they have an increased supply of nitrates, their growth rates will drastically increase. This can cause an array of problems for an ecosystem. One issue that could arise is eutrophication. Eutrophication is when a body of water contains an large amount of nutrients, usually nitrates and phosphates. These different nutrients encourage the excess growth of algae. As the algae and other plants die and begin to decompose, they deplete the water of available oxygen, which makes it difficult for aquatic organisms to survive. This causes fish and other freshwater organisms to die off. Anoxia is when a body of water does not have sufficient oxygen levels to keep fish and other organisms alive. This is caused by excess nutrients in the water causing algae and other plants to grow out of control. When they decompose they use up the available oxygen for this process and fish population begin to suffocate (Partnership For Environmental, …show more content…
Dissolved oxygen is the amount of free, non-compound oxygen available in the water. Dissolved oxygen is the most important factor to aquatic organisms other than the water itself. Dissolved oxygen is nessecary for many different aquatic organisms including fish, invertibrates, bacteria, and plants. They use the oxygen for respiration through their gills or for phtosyntheiss in plants. Animals that live near the bottom of a body of water (like crabs, bottom feeders, and oysters) need small amounts of oxygen, about 1-6 mg/l. Shallow water fish need a little more, around 4-15 mg/L. Microbes also need DO to break down the dead and dying material at the bottom of an ecosystem. If there is not enough DO, the decaying matter can not be broken down, which in turn uses up more DO (Kenker,
Nitrogen and nitrates relate to Hypoxia via the process of eutrophication. Since Nitrogen is a limiting nutrient in most waters, the added input of nitrate causes massive growth in algae. The algae rapidly consume all available N, and once the nutrient is limited again, the alga dies en masse. As the alga decomposes, oxygen is depleted in the water. This lowers dangerously lowers the level of dissolved oxygen in the water, which harms living organisms in the area. Small organisms and organisms that are immobile or unable to escape low-oxygen areas are particularly vulnerable. Hypoxia and resulting “dead zones” are harmful to local fishing and shrimping industries and algal blooms hurt the tourism industry. Hypoxia has lead to a decrease of about 25% in the brown shrimp habitat, forcing shrimping operations further offshore. As the hypoxia issue continues to grow, negative human effects will only increase. Since nitrate runoff from ag. has been proven to be the dominant source of hypoxia, policies could be enacted to effectively deal with “point-source” pollution. This makes enacting environmental policy more easily adapted, possibly included in past policy such as the Clean Water Act.
Fish habitat is the underwater world which many people do not see. It is just like the world that people live. Fish and plants reproduce, eat, and live in this environment, and even face challenges such as invasive species. It is said that “Invasive species are non-native species that threaten the diversity or abundance of native species due to their uncontrollable population growth, causing ecological or economic impacts” (“Invasive” par. 1). Vegetation plays a big role for fish habitat and for a lake itself. Aquatic habitat provides living space for not only fish but also for many aquatic insects. These insects then in turn provide fish and other species of animals with food (“Native” par. 4).
Since water is the medium that the aquarium inhabitants must live in, it is the most vital component in any tank. The quality of the water used will directly effect how successful the aquarium is. The chemical balance of the water must be watched closely. If the salt content varies too much, or harmful chemicals build up, the water will kill the inhabitants of the tank.
The lake’s pH level is slightly acidic at a level of 6 and the lakes dissolved oxygen level is slightly stressful for aquatic life at a level of 4ppm. These slightly stressful levels could be a result of human activity over time and could continue to progress negatively. This could only be determined through years of continuous testing, but is quite possible.
To tell how healthy a body of water is, you would need to measure the amount of dissolved oxygen (DO) in the water. Water is only able to dissolve a certain amount of oxygen to be classified as healthy. And once, the maximum amount of oxygen from the atmosphere that can dissolve in water, which is about 9.8 mg/l, is reached , no more oxygen will dissolve. This shows that water needs to maintain a certain amount of dissolved oxygen, typically 4-5 mg/l, for it to be classified as healthy and to support aquatic animals. If the dissolved oxygen levels drop below 5.0 mg/l, the aquatic life will be put under stress. The amount of dissolved oxygen in the water is affected by several physical and biological (natural) factors.
The water quality in the UHS creek was identified as excellent in the last lab report the was purposed on finding the quality of water. But some creeks or other bodies of water are not as clean as the UHS creek. This is mostly caused humans that negatively impact the water causing the quality to deteriorate. One way humans can negatively impact water quality is by famers putting fertilizers and pesticides on their crops. The chemicals can be washed off by rain and can run into rivers. This in turn causes algae to overgrow in the river (called eutrophication), this turns that water green. When all of this algae dies bacteria break them up using all of the oxygen in the river killing all of the other organisms (http://www.lenntech.com/rivers-pollution-quality.htm).
Dissolved oxygen is one of the best indicators of the health of a water ecosystem. Dissolved oxygen can range from 0-18 parts per million (ppm), but most natural water systems require 5-6 parts per million to support a diverse population (Phosphates).
EPA, U. (Producer). Dissolved Oxygen Concentration- Lake Erie Central Basin Hypolimnion [Print Photo]. Retrieved from http://www.epa.gov/greatlakes/lakeerie/erdo8893.gif
Below is a table of the different trophic states, or levels of organic matter in relation to available oxygen, that a body of water traverses on its way to becoming a "dead zone".
Did you know that aquatic ecosystems cover more than 70 percent of earth’s surface and that three quarters of the earth is covered with oceans, lakes, ponds, rivers, or streams? An aquatic ecosystem is a system composed of living organisms and non-living elements interacting in a watery environment; they also use each other and the water they reside in or near for nutrients and shelter. An ecosystem is an entity formed by the interactions between living organisms and the physical environment. Aquatic ecosystems can be divided into freshwater, estuarine, and marine systems. All of these ecosystems are vulnerable to climate change, pollution, and even over fishing, which can be a serious harm to biodiversity. The organisms that live in these ecosystems contribute to the healthiness of the ecosystems. The main three ecosystems I will focus on will be: freshwater, ocean, estuarine and wetlands.
There is a whole cascading effect when there is too much nutrients going into a body of water like Lake Champlain. There is a limit to how much of a nutrient an ecosystem needs before it becomes excessive. When it does, a process called eutrophication begins, where the amount of oxygen in the lake drops (USGS, 2015). When the oxygen level
The presence of excess nutrients in fresh water bodies can breed bacteria that can kill both livestock and humans if not properly filtered and sanitized. This is particularly problematic in areas that do not have access to clean water such as developing countries. The presence of excess nutrients in water supplies can cause sickness in humans that exacerbates the issues of poverty across the globe. In addition, to humans becoming sick, “Mass mortalities of wildlife have been attributed to cyanobacterial blooms (Dodds et al., 2008). These deaths can be avoided if care is taken in how humans affect the biogeochemical cycles on this planet. Together, all of the impacts mentioned that include losses of aesthetics and use, losses of biodiversity, and decreasing water quality cost large amounts of money to human populations every year. As Dodd’s et al. estimated, just in fresh water ecosystems the annual costs of eutrophication totals more than 2.2 billion dollars annually(Dodd’s et al.2008), and this is a conservative estimate. If the costs associated with salt water ecosystems were added to the costs estimated in fresh water habitats, this number would be much higher. Overall, the issue of eutrophication has massive impacts across many scales and represents a key issue that
Not only do outputs from aquaculture systems dissolve into adjacent waters, but collect as insoluble debris underneath nets and cages. Effluents, feces, excess feed, nutrients, and additional organic matter coat the base of bodies of water in which the livestock are being held, and alter the composition of sea floors (Ackefors & Magnus, 1990). These alterations have the capacity to prevent aquatic plants from growing, thus reducing the amount of available food for wild species (Science for Environment Policy, 2013). According to fishermen in the New Brunswick Bay in Canada, the effects of pollution caused by aquaculture are evident by the smells of sewage and rotten fish that linger in the area, discolored water spreading from nets and cages, and population changes in native species (Wiber, Young, & Wilson, 2012). Heightened levels of dissolved nitrogen and phosphorus commonly result from aquaculture, and can have serious impacts on the health of aquatic ecosystems. Eutrophication will occur as a result, leading to exponential growth of algae populations and the formation of ‘blooms’ that block sunlight from penetrating the water. This then prevents plants from completing photosynthesis, causing oxygen levels to drop significantly (Fisheries and Aquaculture Development, n.d.). Overall water quality in areas surrounding aquaculture systems generally decreases as a result of pollution from these systems. Repetitive testing reports that alkalinity of water in these areas, as well as levels of phosphorous, ammonia, and copper tend to be higher. These changes have the ability to affect the overall health of the surrounding ecosystem, as well as decrease the amount of available drinking water for humans (Marques, 2013). The many discharges from aquaculture systems have detrimental effects on the health of the surrounding ecosystem and species that inhabit the
The pH of natural water stays in between 6.0 and 8.5 but could be affected by chemicals entering the waterways (Chapman and Kimstach 1992). Assessing water quality can be best done with the use of this parameter as it affects many biological and chemical processes within a water body (Chapman and Kimstach 1992, p.62). Extreme pH affects the adaptation of many aquatic macroinvertebrates by disrupting their natural physical and environmental processes. Moreover, the availability of nutrients such as calcium and magnesium may be affected when pH becomes too low from river’s normal
Rogers, Peter. 2008. "Facing the Freshwater CRISIS. (Cover story)." Scientific American 299, no. 2: 46-53. Academic Search Premier, EBSCOhost (accessed November 4, 2010).