Stream Surveys
Stream surveys are a way to evaluate the health of a stream. The insects and other invertebrates (macroinvertebrates) that live in streams can be indicators of its overall condition. Many of these animals naturally congregate in “leaf packs” that collect behind logs and beneath tree roots within the flowing water.
Two aspects of a stream survey are assessing the overall biodiversity within the habitat; as well as the types of macroinvertebrates found. Certain species are very tolerant of pollution. If these organisms are abundant it is an indication that the stream is stressed. Other species are sensitive to pollution. If a variety of these are found, it indicates the stream is healthy and relatively free of pollution.
For our 8th grade classes, we have created our own leaf packs using 30 grams of dry leaf material, onion mesh bags, cable ties, and some string. Bags were deployed in streams connecting to Hunting Creek and Cocktown Creek in Calvert County. After 4-6 weeks, we remove them and bring them to classrooms to investigate! Students sift through the leaves to find and sort the macroinvertebrates. Using a data table and rating system, the health of our streams can be evaluated.
Two aspects of a stream survey are assessing the overall biodiversity within the habitat; as well as the types of macroinvertebrates found. Certain species are very tolerant of pollution. If these organisms are abundant it is an indication that the stream is stressed. Other species are sensitive to pollution. If a variety of these are found, it indicates the stream is healthy and relatively free of pollution.
For our 8th grade classes, we have created our own leaf packs using 30 grams of dry leaf material, onion mesh bags, cable ties, and some string. Bags were deployed in streams connecting to Hunting Creek and Cocktown Creek in Calvert County. After 4-6 weeks, we remove them and bring them to classrooms to investigate! Students sift through the leaves to find and sort the macroinvertebrates. Using a data table and rating system, the health of our streams can be evaluated.