Biological Monitoring Directions

  1. Place the net perpendicular to the flow of water immediately downstream of the sampling area. Remember that the area you are sampling and the duration is dependant on the abundance of life in your stream. You can sample areas of: 1 by 1 foot, 2 by 2 foot, or 3 by 3 foot. You can sample from 20-90 seconds. You take a maximum of 4 samples. If you are unsure, please ask for help.
  2. Weight down the bottom of the net with rocks.
  3. Sample the area for 20-90 seconds.
         - (adjustable - remember the goal is 200 bugs).
        - To sample, lift and rub underwater all large rocks.
         - Dig around in the small rocks and sediments to dislodge any burrowing        macroinvertebrates.
  4. After sampling, carefully rub off any rocks used to anchor the net.
  5. Remove the net with an upstream scooping motion to keep all the macroinvertebrates in the net.
  6. Place the net on a flat, light colored surface. Pick all the organisms off the net into the ice-cube tray.
  7. Once all the macroinvertebrates are removed from the seine, count the number of organisms in the sample. If at least 200 organisms have not been sampled, another net must be collected from a different area in the same riffle or nearby riffle. The organisms from the second net will be added to the first. The length of sampling time can be adjusted depending on the number of organisms collected in the first, with the maximum sampling time per net being 90 seconds.
  8. This process is repeated until at least 200 organisms are found or 4 nets are collected, whichever is first. Each net collected must be sorted in its entirety, even if that leads to a sample of well over 200 organisms.