Strawberry Creek Rapid Bioassessment Project
Project
The Strawberry Creek Committee, maintaining its effort to improve the water and habitat quality in Strawberry Creek, would like to continue to evaluate the water quality on campus this fall. They have requested that the Biology of Aquatic Insects class conduct a macroinvertebrate rapid bioassessment. Your team, after a day of intensive training, will sample sites on Strawberry Creek.
Methods
Sites must be sampled within the same week to ensure temporally comparable results.
Site identification
At each the site to be sampled, describe the location as accurately as possible in your notebook. Mark it on the campus map provided. Selects a reach with flowing water habitats. The reach your group will sample should be about 20 stream widths in length.
Habitat assessment
Using the Habitat Assessment Field Data Sheet, evaluate the habitat at the reach you selected. Each group member will do this independently at each site.
Macroinvertebrate sampling
Sample riffle habitats throughout the reach by placing a D-frame net on the stream bottom and disturbing the substrate for about 1 meter upstream of the net. Allow dislodged benthic invertebrates to drift into the net. Examine cobbles or boulders for clinging invertebrates and wash them into the net. Wash the sample from the net into a white enamel pan. Repeat this throughout the reach for at least 3 points.
This benthic sample should then be sorted and subsampled in the field. This ensures that the minimum required number of specimens are collected. Using forceps and an eye dropper, remove the first 200 invertebrates that you come access. Avoid the natural tendency to grab large, fast, or otherwise conspicuous invertebrates from the pan.
Preserve the 200-organism subsample in alcohol. Place the remaining sample (what’s left in the pan) in a zip-lock bag and preserve it with alcohol (75% Ethanol)
Report
Data from all students in the class will be pooled. Students will each use this complete data set to compare conditions in the stream. Additionally, students will be required to do an additional analysis using data collected by a previous class and make a comparison based between this year’s condition and the past conditions. Students will be expected to turn in a report consisting of introduction, methods, results, and a discussion of the results. Feel free to include charts, graphs, pictures, or maps, if necessary.
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