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Smyrna |
The Effect of Trawling on the
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    Smyrna students sampling the waters!
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Nutrient Pollution
Background Information on Dr. Hans Paerl Dr. Hans Paerl studies nutrient production dynamics at the base of the estuaries and coastal food webs. Dr. Paerl mainly focuses on the environmental control of algal production in the water systems of eastern North Carolina. At the lab where he works they have many research projects underway such as : sources of excess nitrogen in the Neuse River Basin, genetic potential and physiological controls of nitrogen fixation in two estuaries, impacts of atmospheric nitrogen deposition, and phytoplankton ecophysiological responses to changing input dynamics in the Neuse River Basin. Other projects include studies of the sources of production and eutrophication in the Neuse River Estuary. Also the formation and microbiology of modified stromalites, which are the physical/chemical dynamics of cynobacterial blooms in the Baltic Sea and looking for microbial consortia in Arctic lakes.
Description of the Issue Nitrate pollution is a growing problem but there is also a growing awareness of the problems it causes. Nitrogen is one of the many nutrients that occur naturally. Too much nitrogen in any water system can cause an increase in algal growth. Algae is a necessary part of the food chain. However, too many nitrates in the water can cause algal blooms which is very rapid growth or overabundance. Al algal bloom can lead to a depletion of oxygen. The decrease in oxygen impacts other water plants, organisms, fish, and ultimately the coastal economy. Nitrate pollution is a much greater problem in river basin areas than on the immediate coast. This is due to the tides that partially "flush" coastal estuaries of pollutants and excess nutrients. The Neuse estuary is not very well flushed. The mix of fresh and salt water in areas like the Neuse River watershed leads to areas of low oxygen. If fish, shellfish or other marine life become trapped in low oxygen areas, "fish kills" could result. Low oxygen layers are a natural occurrence in many water systems especially during late summer. This problem occurs most often in brackish water. Areas of salt and fresh water do not mix easily together and so the low oxygen layers are common. Because of lack of aeration the condition could lead to loss of fish and plant species or the growth in population of undesirable species. Loss of species can have a disastrous impact on the commercial fishing industry and the fish kills and pollution can adversely affect the tourist economy. Challenges Nitrogen is a naturally occurring nutrient. In some water systems nitrogen levels drop below average and the challenge is to find ways to naturally increase the levels. Other water systems have increased levels of nitrate pollution, leading to decreased oxygen levels. The major challenge is to monitor and find ways to keep nitrogen levels balanced in a way that is healthy for each individual water system. Monitoring levels of nitrates and other nutrients is very important. Studying the short term and long term impact of nitrate pollution is necessary to preserve natural species and protect the estuaries. One continuing challenge is the increase in population of coastal areas and the increase in agriculture in the Coastal Plain region. As more and more people move to the coastal areas and the number of septic systems increase, there is an increase in the amount of nitrates and pollutants enter the water systems. Fertilizer from farms and pollutants from hog farms also add to the problem. Some of the nitrates and pollutants enter the water systems from an unexpected source. Up to 30% of the nitrates can enter the marine environment from the air. As fertilizers are sprayed winds can carry these nutrients over bodies of water. Winds can also carry pollutants that are released into the air over the ponds that hold hog wastes. Solutions
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