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Wetlands:
According to the Environmental Protection Agency (EPA), a wetland is an area where water covers the soil, or is present either at or near the surface of the soil for significant portions of the year, including during the growing season. Wetlands act as the transition between the land and the water. The hydrology of the site plays an integral role in the determining the composition of the soil and the types of aquatic life that live there. Wetlands are unique ecosystems as they support both terrestrial and aquatic life. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promote the development of characteristic wetland (hydric) soils. !aerial2LG.jpg!Source: USGS
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In order to determine the management techniques for a specific waterway in respect to water quality, it is necessary to know the current and desired water quality levels for the waterway. Since the surroundings, hydrology, biota, etc. for each waterway differs, it is not feasible to generalize management techniques for each waterway, especially as water quality variables often interact (such as pH and dissolved metals concentration) (Chapman, 1996). ; we cannot solve a problem if we cannot first identify the problem. As such, it is necessary for each country to establish a system of water quality monitoring and a set of regulations regarding water quality levels. !RPE_AL_Dist5_lg.jpg!Source: USGS
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As indicated by the WHO (World Health Organization) in their report on water quality assessments, the choice of which water quality parameters to use can depend on the use of the waterway or on the expected pollution sources. We recommend that water quality be tested regularly in estuaries and major waterways that drain directly to the ocean; in all cases the water should be clean enough to support aquatic life. Initial attention should be given to the largest waterways and those that are expected to be highly polluted (i.e. those travelling traveling through an industrial sector or city), so that problem areas and areas of great importance are addressed first. Furthermore, by testing a larger body, the effects of tributary streams are taken into account, as those contaminants will still be present in the larger waterway. These tests should measure the following parameters recommended by the WHO for aquatic ecosystems (see chart below). From the data collected, the state of the waterway can be assessed and various solutions can be implemented.
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For parameters that do not meet standards, the source of the contamination should be identified. For point source pollutants that were discharged before the implementation of the law, the perpetrators should be notified of their infractions and ordered to stop the discharges. Polluters should also be given a time frame (suggested time is a year) in which the pollutant's effects must be mediated in order for business to continue. For point source pollutants that were discharged after the implementation of the law, the perpetrator must pay a fine to cover the costs of the environmental damage.
For non-point source pollutants, there are several ways to reduce the effects. Non-point source pollutants are carried into the water by runoff. Water travelling over the land picks up soil and other contaminants and carries them into the waterway. To reduce the concentrations of these contaminants, maintenance and reestablishment of riparian buffers (vegetative areas alongside waterways) is an effective solution, as is maintaining and reestablishing wetlands.
Biological indexes and standards are independent of the pollutant source; they merely categorize the species composition of an area by abundance of species sensitive to pollutants or environmental disturbance, abundance of species somewhat sensitive, and abundance of species tolerant of such disturbance. The complexity of the indexes can vary, but the underlying principle is that a healthy waterway has a variety of species of all three categories, and impaired waterways have a smaller variety and the species that are present fall into the latter categories. If biological monitoring is considered too expensive, it is possible to choose a method of sampling that is less expensive by sampling fish and large macroinvertebrates, since effects will eventually manifest at these levels; studies by the EPA have shown these studies to be more cost effective (EPA, 1988). However, it is important to note that small amounts of contaminants will affect the young and most sensitive organisms first, which may not necessarily be the fish. Monitoring of the habitat may also be taken into accountvaluable in assessing changes.
The EPA's guide to establishing a biological index shows an example of how such a system may be implemented (http://www.epa.gov/waterscience/biocriteria/States/estuaries/estuaries.pdf).
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However, extraction of materials from ecosystems is also an issue in coastal zone management. Extraction of sediments or other mining operations causes severe changes in substrate composition and the overall habitat, not to mention the possible pollutant re-suspension involved in these operations (i.e. of sediments). Extraction of water (either surface water extractions or ground water extractions, as from wells) itself also changes the aquatic ecosystem in many ways-\--both from a physical and chemical standpoint. Information about the effects of dams on water quality is \[here-\-LINK TO DAMS PAGE\]. |
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For water withdrawals (or large water discharges, specifically of coolant water) we propose the use of IFIM (Incremental Flow Incremental Methodology) to evaluate the effects of the withdrawal before it takes place, so that planning and permitting can take place before withdrawals begin. The IFIM model can be used to predict how changes in flow will affect various other water quality parameters like temperature and how these changes will affect fish populations (Young, 1997). The results of the model can be used in the permitting process to make initial suggestions and limitations; however, regulation should be elastic enough so that withdrawal limitations can be changed if harm is observed. Special attention should be given to processes which may fundamentally alter sediment and nutrient transport, as alterations can negatively impact estuarine and lower waters to a great extent, as discussed in the page on dams \[LINK TO DAMS PAGE\]. |
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Future research should look explore alternative forms of ballast that that involve water contained in tanks that can be temporarily jettisoned and then reclaimed or other mechanisms to purify water within the ship. In this way, the transport of invasive species would be greatly diminished. Interested countries should support research into alternative forms of ballast.that minimize the risk of invasive transport.
However, many invasive species travel via other means---including intentional release (ex. Hydrilla in United States) such as the introduction of the red-eared slider in the United States (PA's 10 Least Wanted). To prevent this, strict trade regulations should be placed that prohibit the transport of non-native species between countries and between waterways within the same country to another (PA's 10 Least Wanted).
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