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humans when the blooms reach close to shore. Liebig’s Law of Limiting Factor -Growth is not controlled by the total amount of resources available, but by the scarcest resource (limiting factor). Why is high turbidity considered bad? -Turbidity usually caused by growth of phytoplankton -High turbidity reduces the amount of light reaching lower depths which can inhibit growth of aquatic plants –this can affect species which are dependent on them such as fish -High turbidity also affects the ability of fish gills to absorb dissolved oxygen What were the causes of the Exxon Valdez oil spill? -Failure of crew to properly maneuver the vessel because of fatique -Failure of master to provide a proper navigational watch because of impairment from alcohol -Failure of Exxon Shipping Company to provide sufficient crew -The spill affected 1900 km of Alaskan coastline. According to reports, 10.8 million gallons of oil were spilled. find more resources at oneclass.comfind more resources at oneclass.com
What is the Haber-Bosch process and what has it been called the “most importantinvention in the 20thcentury”?-Under high temperature and pressure, hydrogen and nitrogen (from thin air) are combined to produce ammonia. Nearly one century after its invention, the process is still applied all over the world to produce 500 million tons of artificial fertilizer every year. -Haber and Bosch were two scientists who discovered that NH3 can be formed under high temperatures and pressures by combing hydrogen and nitrogen. Nitrogen is the most important nutrient for plants and food production. It is sustaining roughly 40% of the population living on Planet Earth. -Billions of people would not be able to survive if it weren’t for the production of food skyrocketing due to the production of synthetic NH3. -Nitrogen produced naturally is very low and in limited quantities. What is residence time? -The duration of persistence of a mass or substance in a medium or place What is a trophic cascade? -It is an ecological phenomenon triggered by the addition/removal of top predators involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes within an ecosystem structure and nutrient cycling. What is a nitrogen glut? -The recent rapid increase in the nitrogen available in an environment is known as a nitrogen glut. The nitrogen glut threatens air and water quality, disrupts health of terrestrial and aquatic ecosystems. -This is caused by: oIncrease in the use of fertilizer oIncrease in fossil fuel burning oIncrease in land clearing and deforestation What causes hypoxia problems in the Gulf of Mexico? -Freshwater discharge and nutrient loading of the Mississippi river -Nutrient-enhanced primary production (eutrophication) -Decomposition of biomass by bacteria on the ocean floor -Depletion of oxygen (hypoxia) due to stratification (forming of different nutrient-based layers that act as barriers to water mixing) What are the cause-effects relationship that result in fish kills in the Neuse River Estuary?