Groundwater-dependent ecosystems face a greater threat of pollution. In many cases groundwater can become polluted through toxins, or even just excessive amounts of certain nutrients seeping down to the water table. This polluting of the groundwater can have many different effects on the related ecosystems in the case of an estuary in Cape Cod it was noted that an influx of new nitrogen had come from septic tank fields in the groundwater’s flow path. Increased levels of nitrogen in aquatic ecosystems can cause eutrophication which is the process of excessive introduction of nutrients causing an abundance of plant growth which can result
Baltic Sea hypoxia lack of oxygen (anoxia) kills bottom-living organisms and creates dead zones. The rapid increase in hypoxia in coastal areas around the world is due to the excessive inputs of plant nutrients, such as nitrogen and phosphorus by human activities. The sources of these nutrients include agriculture, sewage, and atmospheric deposition of nitrogen containing compounds from the burning of fossil fuels. The nutrients stimulate the growth of algae causing problems with eutrophication. The algae sink to the bottom and use the oxygen when they decompose. If mixing of the bottom waters is slow, such that oxygen stocks are not renewed, hypoxia