Summary of lesson: The purpose of this lesson is to help students understand the importance and design of standardized field protocols in ecological research and environmental assessment, as well as providing experience in data collection, calculation of some important descriptive statistics, and stream macroinvertebrate collection and identification. Working in small groups, students will collect, identify, and analyze a stream macroinvertebrate community as a way to explore how sampling protocols influence data quality and reliability. The lesson begins with students designing and carrying out their own sampling procedures in the manner they see fit, then evaluating variability in the results among groups in their quantification of stream health based on macroinvertebrate diversity. The lesson ends with performing and evaluating the results of a standardized U.S. Environmental Protection Agency protocol. The activity can take place in any wadeable stream site where macroinvertebrates are reasonably abundant. Learning outcomes: After completing this lesson, students will be able to: calculate and interpret a coefficient of variation (CV). perform a standardized rapid bioassessment protocol for macroinvertebrates. explain the value of reliable, standardized protocols and the factors that contribute to good protocol design. Target audience: This lesson is especially well-suited to students who have already had some biology, ecology, or environmental science background (e.g., an introductory course) that would have introduced skills in close observation of organisms, a basic understanding of using identification keys, and provided experience with data collection. With that preparation, this lesson would lead students to consider how data collection protocols are designed and how to practice fieldwork in a replicable and reliable manner, preparing them for more advanced study. It could also be used in an introductory course, with the expectation that students will be less detail-oriented and attentive to characteristics that aid in macroinvertebrate identification. Prior knowledge of the concept of statistical mean is assumed, and knowledge of a standard deviation would be helpful but will be reviewed. For most students described above, the activity will probably require two lab periods (including some pre-lab and post-lab work), with one lab period used for student-devised sampling activities and the second lab period for execution of the standardized protocol. If students have had previous coursework involving field-based data collection, or if prior lab activities in the same course have already introduced them to field sampling and working in stream environments, then it may be fit within a single 3 hour lab period. Some students may have limited experience in the outdoors or in aquatic environments or in the handling of wild animals. Such students may find wading in the water and/or handling macroinvertebrates to be an uncomfortable experience, distracting them from the learning experience. Some students may also face physical limitations in their ability to wade in the water (especially with uneven surfaces and the force of the current). The groupwork inherent in the activity should allow all students to contribute, even if they stay on the bank or do not handle the invertebrates. Tasks including recording data, calculations, discussion, etc. do not require students to leave the shore to participate in those components of the lab. Gloves and/or long forceps (or other tools) to manipulate and handle macroinvertebrates may also raise comfort levels for some students. If some students have extensive experience with different macroinvertebrate taxa (e.g., entomology coursework), they may be much faster at identifying and sorting specimens. In such cases, it may be best to either group such students together to prevent them from overwhelming and outpacing their peers when groups sort their samples, or integrate a peer teaching model where those students are explicitly directed to provide instruction and oversight.
Brad Carlson (Thu,) studied this question.