Biological
Monitoring Directions
- 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.
- Weight down the bottom of the net with rocks.
- 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.
- After sampling, carefully rub off any rocks used to anchor
the net.
- Remove the net with an upstream scooping motion to keep all
the macroinvertebrates in the net.
- Place the net on a flat, light colored surface. Pick all
the organisms off the net into the ice-cube tray.
- 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.
- 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.
REMEMBER THAT THE GOAL IS TO GET 200 BUGS or
more.
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