Measuring Water Quality How do scientists measure water

Measuring Water Quality

�How do scientists measure water quality? �Water samples, aerial photography, and aquatic life forms �The health of a water body can be determined by analyzing physical, chemical and biological factors

�What chemical factors are used to measure water quality? �Dissolved oxygen (DO) �How much oxygen is available for organisms to breathe �What photosynthetic organisms are making/using oxygen �p. H �Measure of chemicals dissolved in water �Too high or low can be deadly

�What chemical factors are used to measure water quality? �Nutrients �NPK �Too many can stimulate algal growth eutrophication �Toxins �Metals, pesticides, oils, etc

�What physical factors are used to measure water quality? �Temperature �Dictates what life forms can survive �Correlated to the amount of direct sunlight �Warmer water contains less DO than cold water �Amount and speed of water �Some water is slow moving or even stagnant, where as obstructions or curved paths can create rapids

�What physical factors are used to measure water quality? �Substrate on bottom �Large sediments stir up more water, increasing DO �Turbidity (Clarity) �How much solid is being carried in the bedload

�What biological factors are used to measure water quality? �Pathogens �Viruses and bacteria (fecal coliforms), mostly from failing septic systems, untreated human waste, and animal waste �Bioindicators �Living things that provide information about water quality �Fish, plants, and macroinvertebrates (snails, worms, larvae) �Only species most tolerant will be found in heavily polluted waters