Water quality research
Water quality
Hydrologic optics

Components of water quality

SERC water research projects
CISNet program

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 Water Quality

    Water quality is determined by the water's physical, chemical and biological properties, which can have a profound impact on the overall health, or ecological state, of the water.

  • Water is necessary for all life on the planet
  • Bodies of water act as habitat for both flora and fauna, from fish, mammals and waterfowl, all the way down to seagrasses, phytoplankton, bacteria, and viruses.
  • Bodies of water fill a vast array of human needs, from drinking water to commercial uses to recreation and aesthetics.

    One way to assess water quality is through hydrologic optics: the way light behaves under water. The color and clarity, or the visual appearance, of water is determined by the amount and kind of materials dissolved and suspended in it. This visual appearance is how most people assess the cleanliness of the water and its suitability for recreational purposes. Therefore, connecting optical properties of water with monitored impacts may become an effective way to assess habitat change in a wide range of coastal areas.

    All water bodies are impacted by natural and anthropogenic, or human-induced, stressors. Stressors are events and inputs that affect ecosystem function.

Natural Stressor

Impact

Large Storm (including spring melting)

Increases the sediment load by way of increased erosion and increases eutrophication

Drought

Changes salinity distribution, therefore altering habitats of salt-dependent species

High winds

Increases sediment load by stirring water, resuspending bottom sediments and blowing additional sand and soil into the water and increases eutrophication

    Eutrophication refers to the over-enrichment of the water by nutrients, which increases phytoplankton (floating, microscopic algae) growth. Nutrients, principally nitrogen and phosphorus, are often carried into coastal waters attached to sediments and by precipitation, which is why phytoplankton blooms result from large storms, which increase nutrient loading. Nitrogen and phosphorus are key nutrients in the eutrophication of estuaries and coastal bays.

Human Activity

Impact

Agriculture

Increase in nutrient and chemical contaminated runoff, increase in the volume of runoff

Dredging

Changes the distribution of benthic communities and disturbs bottom sediments, increasing the sediment load and potentially re-releasing settled contaminates and attached nutrients

Power Generation

Contaminates the water and causes temperature pollution

Sewage Discharge

Increases the nutrient load

Urban Development

Increases runoff, erosion and contamination
        Coastal ecosystems are particularly impacted by anthropogenic stressors because of increasing development pressures within the coastal zone.

    Monitoring water quality is an important step in identifying changes in water quality and the underlying causes of these changes. Using hydrologic optics to monitor water quality is one approach which may move us closer to cleaner water. The CISNet grant at SERC is allowing researchers to perform this type of monitoring.

    Another reason for improving water quality, especially in the Chesapeake Bay area, is to aid the survival of seagrass communities.

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Smithsonian Environmental Research Center
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