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Estuaries 101 A Brief Introduction to Natural and Human-Induced Processes in Estuaries. Jonathan Pennock University of New Hampshire Marine Program, NH Sea Grant & Jackson Estuarine Laboratory. What Are Estuaries and Why Should We Care About Them?.
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Estuaries 101A Brief Introduction to Natural and Human-Induced Processes in Estuaries Jonathan Pennock University of New Hampshire Marine Program, NH Sea Grant & Jackson Estuarine Laboratory
What Are Estuaries and Why Should We Care About Them? • Semi-enclosed bodies of water where fresh water & salt water mix… • Estuaries are critical habitats for many ecologically and economically important coastal species… • Estuaries are natural biological and geochemical reactors… • While net flow is almost always from the land to the sea, tidal influences and often two-layered flow tend to retain materials in estuaries… • In most, but not all estuaries, freshwater input from the watershed is the major source of nutrients, contaminants, suspended sediments, etc… • The sources of these inputs varies, however, with ‘point-sources’ from specified inputs and ‘non-point sources’ from varied sources such as precipitation, agriculture, septic tanks and groundwater contributing… • Different estuaries have differing capacities to cope with human perturbations based on their physical and geological make-up…
What are the Most Critical Factors Impacting Estuaries? • Habitat Loss • Bacterial Contamination • Chemical Contaminants • Loss of Keystone Species • Sediment Inputs • Nutrient Over-Enrichment • Micro-algae and Macro-algae Overgrowth • Hypoxia & Anoxia
NOAA Eutrophication Model Bricker 1999
EutrophicationPositive Versus Negative Effects Oligotrophic Mesotrophic Eutrophic Dystrophic Phytoplankton Zooplankton Pelagic Fish Bottom Oxygen Benthos Benthic Fish
Population Increase Adapted from Nixon, 1994
Fertilizer Production Adapted from Nixon, 1994
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