ECOL 1000L Lecture Notes - Lecture 3: Identification Key, Tally Marks, Net.
Then, we used a D-net and collection tray to collect organisms from three separate
spots at each watershed. While one person held the D-net in the stream where
water moved rapidly, the other person disrupted the sediment around the area for
approximately one minute in order for the organism to flow into the net. Once the
time passed, we dumped the contents of the D-net into the collection tray along
with clean water for examination. We then utilized a magnifying glass and tweezers
to find organisms and identify the macro-invertebrates using the identification key.
Every time an organism was discovered, we recorded a tally mark on our
spreadsheet.
In order to calculate the bioassessment index from the organism we
discovered, we utilized an index formula: Index= (# sensitive taxa * 3) + (#
somewhat sensitive taxa *2) + (# tolerant taxa * 1).
RESULTS
Shown on Figure 1, at Lily Branch, our bioindex value was 36 and was 45 for
Orange Trail Stream. It is shown in Figure 4, the Bioindex table, that the Orange Trail
Stream had 8 sensitive organism, 8 somewhat sensitive organism, and 5 tolerant
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Document Summary
Then, we used a d-net and collection tray to collect organisms from three separate spots at each watershed. While one person held the d-net in the stream where water moved rapidly, the other person disrupted the sediment around the area for approximately one minute in order for the organism to flow into the net. Once the time passed, we dumped the contents of the d-net into the collection tray along with clean water for examination. We then utilized a magnifying glass and tweezers to find organisms and identify the macro-invertebrates using the identification key. Every time an organism was discovered, we recorded a tally mark on our spreadsheet. In order to calculate the bioassessment index from the organism we discovered, we utilized an index formula: index= (# sensitive taxa * 3) + (# somewhat sensitive taxa *2) + (# tolerant taxa * 1). Shown on figure 1, at lily branch, our bioindex value was 36 and was 45 for.
