Matching a Stream With its Bug Population
Students will match the physical descriptions of two streams and the topographical maps of those streams with the contents of 2 leaf packs. These leaf packs will be from the 2 streams but their orgin will not be identified.
Objectives
Students will look through their leaf packs to identify invertebrates and build a picture of the stream habitat that is home to these critters.
Students will predict which leaf pack belongs to which stream.
Students will justify why they believe one leaf pack comes from one of the streams using their macroinvertebrate results and the physical conditions of the stream to help them.
Materials
2 leaf packs from 2 streams
Pans to wash invertebrates into
Hand lenses
Discovery Scopes
Macroinvertebrate Keys Aquatic Invertebrate Data Charts (These are the "stream report cards" for each stream) MBSS information for each of the streams
Topo maps of each of the stream corridors
Procedure
1.  Students will find as many of the macroinvertebrates in their leaf packs as they can. They will use their I.D. charts to identify the invertebrates in their leaf packs.
2.  Students will track the numbers and types of invertebrates on their Aquatic Invertebrate Charts.
3.  The students will calculate the stream health based on the biotic index and EPT percentage. They will match one Aquatic chart with one of the streams from the MBSS information page and Topo Map.
References
* All lab equipment courtesy of Donna Gates, Research Assistant at the Macroinvertebrate Lab of the Appalachian Lab; Frostburg, Md. * Macroinvertebrate Key developed by Donna Gates; Illustrations from Voshell, J.R., Jr. 2001. A Guide to Common Freshwater Invertebrates of North America. 442pp. McDonald and Woodward Publ. Co. Blacksburg, Virginia
* Aquatic Invertebrate Data Chart courtesy of Leaf Pack Network: http://www.stroudcenter.org
* Site information on specific streams courtesy of Maryland Biological Stream Survey: http://mddnr.chesapeakebay.net/mbss
* EPT and Biotic Indices courtesy of Maryland Biological Stream Survey: http://mddnr.chesapeakebay.net/mbss
State Standards
3.5.1- The student will analyze the relationships between biotic diversity and abiotic factors in environments and the resulting influence on ecosystems.
3.5.2- The student will analyze the interrelationships and interdependencies among different organisms and explain how these relationships contribute to the stabilty of the ecosystem.
6.2.2- The student will explain why interrelationships & interdependencies of organisms contribute to the dynamics of ecosystems. At least Interspecific and intraspecific competition Niche Cycling of materials among organisms Equilibrium/cyclic fluctuations Dynamics of disturbance and recovery Succession: aquatic and terrestrial
6.4.3- Interpret the findings to draw conclusions and make recommendations to help resolve the issue.
Lesson Resources