1. a Biological Study of Macroinvertebrates in the Leibert Creek
Stream Monitoring Research 2010
a Biological Study of Macroinvertebrates in the Leibert Creek
By Kevin, Chris, Alex, Brittney and Gianni

2. Procedure Use nets to collect macroinvertebrates from the stream.
Identify each macroinvertebrate using a key and create a table to summarize data.
Use different indexes to calculate the amount of pollutants in the stream.

3. Data 370.5 Organism N Ti Tv Flatworm 1 6.0 6 Sowbug 8 48 Scud 20 4.0
Data
Organism N Ti Tv
Flatworm 1
6.0 6
Sowbug 8 48
Scud 20
4.0 80
Dragonfly 5
4.5
22.5
Narrowwinged Damselfly
5.5 33
Mayfly Minnow Siphlonuridae 3
7.0 21
Swimming Mayfly Baetidae 2
Other Mayfly 7
3.0
Hydropsychid Caddisfly 9
49.5
Non-Hydropsychid Caddisfly
3.5
31.5
Water Penny Beetle 24
Crane Fly
Left-Handed Snail
9.0 18
TOTALS
370.5
TAXA = 13 ∑N
∑Tv

4. Family Index or MBI
=∑Tv / ∑N
=370.5/80
=4.631
This tests water quality using the sample density and the tolerance of each species of macroinvertebrate.

5. Index of Biotic Integrity
Parameter Score
Species Richness
Between 11 and
EPT Index
Between 2 and 5 6
% Dominant Species
<30%
Total
Impact Rating Good

6. Sample Richness This tests the diversity of the species found.
>26 = non-impacted
19-26 = slightly impacted
11-18 = moderately impacted
<11 = severely impacted
Number of Species = 13
This shows that the stream has been moderately impacted by pollutants.

7. EPT Index
This index uses the number of mayflies, stoneflies and caddisflies to determine how impacted a stream is.
Number of flies = 5
Status of Stream = moderately impacted
Stonefly
Mayfly
Caddisfly

8. Percent Dominant Species
Divide the number of the most common species by the total number of the sample.
(20/80) = .25
.25*100 = 25%
<30% indicates that the stream is not impacted.

9. Analysis
2 Evaluate the quality of the stream, based on the macroinvertebrate index results.
The quality of the stream seems to be fair to good. One reason we concluded this is based on the large variety of macroinvertebrates we found, especially since we found high numbers of most species. Another reason we think the quality of the stream is good is the fact that many of the species we discovered are known generally as good indicator species. These organisms, specifically caddisflies and mayflies, were found in high numbers in the Leibert creek.

10.
Analysis Cont.
3. Do you think acid precipitation affects this stream? Why or why not?
Acid precipitation may affect the stream, but it is not a prevailing pollutant. When looking at the different groups of macroinvertebrates, we noticed many mayflies and caddisflies. These different macros are not extremely tolerant to acidity in water. This lead to the conclusion that acid precipitation is not a huge pollutant in the stream.
Other possible causes of pollutants could be slight
Industrial problems or agriculture. Ways to reduce
Pollution in this stream could include more regulation
Of the stream and higher enforcement laws.

11. Works Cited
"Freshwater Benthic Macroinvertebrates." Maryland Department of Natural Resources. 6 May Web. 07 Nov <
Dangles, Olivier J., and François A. Guérold. HYDROBIOLOGIA. 1st ed. Vol Netherlands: Springer. Print
"Effects of Acid Rain: Lakes & Streams." D. W. Brooks Site. Web. 08 Nov <

12. The End