Recreational Waters

Condition focuses on the physical, chemical, and biological attributes that determine a water body's ability to support recreational activities. These attributes vary widely, depending on the activity, but fall into two main categories: those affecting human health and those affecting ecological systems.

• Human health. These attributes—primarily concerned with pathogens, biological and chemical contaminants—determine whether people can enjoy recreational activities without risk to human health. People can be exposed to contaminants if they swim in contaminated waters or near storm water or sewage outfall pipes, especially after a rainfall event. Swimming in lakes affected by blooms of cyanobacteria could also increase risk of exposure to microcystins, produced when some cyanobacterial species degrade.
  
  People can be exposed to contaminants through skin contact, by swallowing water, or through eating recreationally-caught fish (see Consumable Fish and Shellfish). Effects can range from minor illnesses to potentially fatal diseases. Children, the elderly, and people with compromised immune systems are most at risk.
• Ecological systems. These attributes are associated with ecological systems that support recreation. Examples include the status of fish, bird, insect, and other invertebrate communities and the biological, chemical, and physical characteristics of the water that affect these populations and their habitat.
  
  These attributes also contribute to aesthetic qualities that are important for recreation. For example, the presence of dead fish, harmful algal blooms,  or visibly unhealthy plants might diminish one's enjoyment of recreation in or near the water. Additionally, ecological effects can also affect human health. For example, harmful algal blooms can cause adverse effects in aquatic life and affect people or pets who come into contact with them.¹
  
  The condition of recreational waters is affected by chemical and biological contaminants, as well as other stressors.
  • Sources of contaminants. A wide range of sources contribute chemical and biological contaminants, which affect both human health and ecological systems. Sources include storm water and urban runoff, agricultural runoff (often rich in nutrients and sediment), direct discharge from industrial facilities and sewage treatment systems, atmospheric deposition (such as acid rain), and recreational activities themselves (such as outboard motor exhaust and overboard discharge of sanitary waste).
    
    The abundance of chemicals and pathogens in water can be affected by land use and land cover (such as paved surfaces and forestry and irrigation practices) and by weather and climate. For example, an excess of nutrients can lead to an overgrowth of cyanobacteria, some of which are able to produce toxins that are harmful to human health and ecological systems. 
  • Other stressors to recreational waters can affect habitat, species makeup, and important ecological processes. For example, changes in land cover (such as removal of shade trees) can raise water temperature above the viable range for certain fish species. Hydromodifications such as dams may create some recreational opportunities (such as for boating), but also may obstruct migrating fish species such as salmon.

ROE Indicators