Taxonomy

The Biology Program's Taxonomy staff performs species-level taxonomic analyses of benthic macroinvertebrate and algal samples, and some are experienced field samplers that assist in department program sampling efforts. Studies combining benthic macroinvertebrate and algal community sampling provide a valuable assessment of the overall health of aquatic systems. Advantages of using macroinvertebrates and algae include their ease of sampling, their strategic positions in the food web, and their ability to respond quickly to (within days or weeks of) of a physical or water quality disturbances. Since the adoption of statewide numeric nutrient criteria in 2011, evaluations of taxonomic data aid in determining if a stream’s nutrient concentration is protective of a well-balanced aquatic community.

Resident aquatic, benthic macroinvertebrates must respond to both chemical and physical changes in their environment. Many organisms are adapted to handle natural environmental stressors like seasonal drought and temperature or dissolved oxygen fluctuation. Some species are more sensitive or tolerant to pollutants than others. Identifying which organisms are living and reproducing in the water provides a measure of the cumulative impacts of pollutants and stressors and a holistic picture of water quality and the biological health of a system.

The periphyton community is made up of algae inhabiting the surfaces of underwater vegetation, wood, rocks, and other substrates. The phytoplankton community consists of free-living algae which are suspended in the water column. Because algae are primary producers and form the base of the food web, higher organisms depend on them for food and for the oxygen released during the process of photosynthesis. These plant-like organisms have an extremely high rate of reproduction; therefore, in the presence of sufficient light,ample nutrients and warm temperatures, their populations can explode into blooms which can contribute to oxygen depletion, fish kills, and aesthetic problems that can interfere with recreational use. Additionally, many blooms have the ability to produce toxin which can be harmful to human health and the environment.