[experiment to see if their faces would freeze this way ! --- rjg]
Left to right-
Top Row: Jasmine Anderson-Junior, Josh Blacketer-Senior, Coreen Strozyk-Junior
Bottom Row: Robyn Melton-Junior, Brenda Walters-junior
E mail: nkn@oregoncoast.com
(Located in Rockaway Beach, Oregon)
We wanted to see if different sites on the Miami River have different types and numbers of aquatic insects. There are three sites that we are studying: site A was manipulated three years ago, site B was manipulated two years ago, and site C was left untouched. The amount of food and oxygen are important factors for the insect population along with the temperature, velocity, and substrate type of water. These insects are a main food source for salmon. Since the insects and the salmon have some of the same ecological needs the amount and types of insects found at each site are used as an indicator of how the salmon population is doing . From this we can determine which site is most adequate.
We set out 2 traps at each of our sites for a total of 6 traps for each date we sampled. occasionally equipment failure prevented us from running all 6 traps.
Traps: The traps consisted of a 5 gallon bucket filled with 70% ETOH. Hanging above the bucket were battery run lights. The insects would be attracted by the alcohol , fly into the bucket, and then be trapped in the alcohol.
Traps were set on 12 different dates , close to every other week between the end of May 1995 and the end of October 1995. Traps were set out at dusk and recovered the following morning at dawn. Contents of each trap were poured into jars.
Collected samples were brought back to the High School where we counted each individual insect and sorted them to correct order.
Site A: Site A is our farthest downstream site. In 1992, the Oregon Department of Fish and Wildlife manipulated this site to create side stream channels called alcoves. The purpose of an alcove is to provide shelter and resting sites for young fish. Two traps are run at these alcoves.
Site B: Two traps are run along the stream side at this middle site which was manipulated by the Oregon Department of Fish and Wildlife in 1994. Large boulders and large trees were placed within the existing stream channel and anchored into place with wire cable.
Site C: This unmanipulated site is located farthest upstream. Two traps are run near the stream channel.
We've set traps at the three sites 12 times between May and October about once every two weeks, and collected 70 different traps. To date we have sorted the samples from 6 of a total of 12 collection dates and counted over 53,900 insects. 14 different orders have been identified so far. 3 aquatic orders we are most interested in are:
Order Tricoptera(caddisflies)
Order Ephemeroptera (may flies)
Order Plecoptera (stoneflies)
We are also interested in a the percentage of total insects found at each site. By comparing the two pie graphs, we find that site C has the greatest percentage of total insects on both dates. This seems to be the trend for all samples sorted so far. Remember, site C is the unmanipulated site.
We find more orders are present later in the year. Again, site C shows the greatest number of orders.
