Eutrophication and hypoxia create dangerous problems for water bodies like lakes, estuaries and coastal waters. Within the past 50 years, eutrophication — the over-enrichment of water by nutrients such as nitrogen phosphorus — has emerged as one of the leading causes of water quality impairment. The two most acute symptoms of eutrophication are hypoxia (or oxygen depletion) and harmful algal blooms, which can destroy aquatic life in affected areas.

  • Eutrophication happens when there is an abundance of nutrients in water bodies, which can result in harmful algal blooms, dead zones and fish kills. This is frequently caused by runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
  • Hypoxia, or low oxygen levels, happens when a water body has dissolved oxygen concentrations of less than 2-3 mg/L. This can be caused by excess nutrients (primarily nitrogen and phosphorus) and waterbody stratification (or layering) due to saline or temperature gradients. These conditions can lead to algal blooms and eutrophication.

WRI’s research has found that lack of public awareness of these issues is one of the main reasons they are not addressed. WRI, in partnership with the Virginia Institute of Marine Science (VIMS), has developed resources on the extent to which freshwater and coastal ecosystems experience eutrophication and hypoxia, as well as their drivers and impacts. By providing accurate, reliable and comprehensive information about the causes, effects and location of eutrophication worldwide, WRI and VIMS aim to:

  • Raise awareness and support among policymakers, the media and the public on issues surrounding eutrophication and nutrient pollution;
  • Provide information and resources on the subject of eutrophication and hypoxia;
  • Increase dialogue and information exchange on these issues; and
  • Identify data gaps that exist for identifying areas impacted by eutrophication.

This project was supported through a generous grant from the David and Lucille Packard Foundation.