Why do we analyze the water data?

As part of our IGAP grant, one of GTC's goals is to establish a water quality baseline to ensure the continued health of the Kuskokwim River alongside responsible development.   Having a reliable and consistent set of data to establish what is called baseline data, allows us to address changes to the quality of the water that may occur due to various external influences such as human activities on the river, mining operations, etc.  Parameters such as pH, conductivity, temperature, and dissolved oxygen (DO) are used to measure the quality of the water on site.  

You’ve already read about what these parameters are, but why do we use them? 


Thermal pollution is an increase in water temperature caused by adding relatively warm water to cooler water.  Measurement of temperature change can help detect the cause of thermal pollution.  High water temperatures can stress aquatic ecosystems by reducing the ability of water to hold essential dissolved gasses like oxygen.  


Most aquatic plants and animals are used to life in water with a specific pH. Changes in pH may reduce reproduction, and could be deadly.  Mining and the discharge of industrial or residential pollutants directly into waters are examples of activities that can have a negative impact on a water’s pH level.  Mining may expose rocks to rain water and produce acidic runoff, thereby decreasing its pH and making the water more acidic.  As you can see in the pH scale in the previous article, as pH levels decrease, dangers to a variety of aquatic organisms increase.


Dissolved Oxygen is essential for aquatic life.  The presence of aquatic plants, the temperature of the water, the amount of suspended solids in the water are all examples of factors that affect the amount of DO in the water.  Removal of riparian vegetation decreases DO, and human activities causing runoff decrease DO by increasing the amount of suspended and dissolved solids in the water.   


An increase in suspended solids in the water affects water quality in many ways - the particles absorb heat from sunlight, increasing water temperature and thus causes oxygen levels to fall.  Photosynthesis decreases because less light can penetrate the water, further decreasing oxygen.  Suspended solids can also clog fish gills, and smother the eggs of fish when they settle.  Some activities that can increase turbidity are runoff from construction, logging activities, and discharges.



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