The Effects of Stream Source Distance on Fish Diversity

This topic submitted by Jesse, Liz, Nathan, Drew ( See class listserve ) on 10/15/00 .

For our study, we are going to examine the diversity of fish populations in a stream from its source to its mouth. We hypothesize that as we approach the mouth of the stream, the species diversity and abundance in the fish populations will increase.
We selected this topic after a conversation with fish expert Donna McCollum. She was instrumental in helping us find a specific area to research. She took our interests into account, and helped us focus on possible methods of surveying and conducting our reasearch.
Our goal for this project is not only to gather accurate scientific data, but also to gain a better understanding of the scientific method and to use this as a personal learning experiance. Also, we'd like to use this exercise as an opportunity to apply research and literature to real world situations.
We feel that this project is relevant to GLG 205 in several ways. First of all, we're using methods of representative sampling similar to those used in the clover lab. Also, research has shown that diversity in a natural evirnoment is critical in maintaining stable populations in times of environmental stress (we have a citation, but left it at home). This topic is covered several times in "The Song of the Dodo (we don't know how to underline in HTML)."
This project is interesting because we may see results very different from what we are hypothesizing. This could lead to the generation of new hypothesis and further research. Also, this is interesting because we get to observe first-hand the role evolution plays in diversity, and how each species occupies it's own niche.

Materials and Methods
The materials for our experiment are simple. We require a five gallon bucket, a seine (3/8 inch holes), 2 sticks (to support the seine), a clipboard (with paper and pen), and a long-handled net.
The design of our experiment is also simple. Our group intends to seine sections at equal intervals along a stream from the source to the mouth. With each sample we intend to identify each captured fish, and record the abundance and diversity of the fish at every site. When all the sampling is completed we will compare the results with the hypothesis.
For our study, we are using Harker's Run. This is a fairly shallow, and short stream located North/Northeast of the city of Oxford. It is approximately 3.75 miles in length from source to mouth.
We have broken Harker's Run into 3 approximately equal sections to study. The first is at the Miami Stables (the mouth), the second is at the overpass at Bonham Rd.,and the third is from beyond the overpass at Summerville Rd. (as close to the source as we can get without trespassing on the private property of people with guns).
At each section we intend to sample for 20 minute periods of time, and trying to get as wide a variety of habitats as possible (riffles, pools, sun, shade, etc). We have found that this gives us about 4 samples at each site.
We intend to go out and sample at each site 3 times. Then we will average the data together to make the comparisons and correlations to our hypothesis.
The technique of seining is very straight forward. Basically, a seine is a net tied between 2 sticks and stretched across the stream. Fish are caught up in the net and then placed in a bucket. our group will be employing 2 techniques to capturing fish in the net:
The first is called "Kick Seining" and used in places with slightly higher currents (riffles). To accomplish this, the seince is stretched at the most downstream point of the riffle by 2 group memebers. The rest of the group lines up at the top of the riffle and walks towards the seine, kicking up and disturbing the substrate as much as possible. In essence, this scares the fish into the net.
The second technique is more conventional and involves 2 group members holding the seine and walking with it very slowly. The seine can be steered towards likely habitats or schools of fish seen below the surface. The rest of the group helps spot schools of fish, and walks ahead of the seine and scares the fish towards the net.
A third technique, which our group will not be using is the "Fish Shocker." This involves integrating a portable generator and a DC current adaptor to a backpack frame and carrying it out into the water to shock fish. The current puts the fish in tetany, causing them to float to the surface for collection. We will not be using this device because it's fairly inefficient for our purposes. We couldn't get a very large sample with it. Also, it's out of gas.
We're fairly confident that our experimental design is sound. Dr. McCollum assisted us in the drafting of our experiment, and even went out into the field with us to instruct our group on various sampling techniques and methods of fish identification.
Input from the class in the way of constructive criticism will be greatly appreciated. We'd love to hear any suggestions or comments that the class may wish to offer. Other than supplying our group with feedback, we don't see where they could really get involved with our study (i.e. processing data).
Our group has constructed data sheets, but it is hard to include them in HTML format so we will offer a brief description. We have a data sheet for each of the 3 sites we intend to sample at. On each data sheet there are four columns, one for each sample. In each column, there is a place to list the species we capture and the amount of individuals of each species. At the bottom there are places to list the totals.
Timeline of Research Execution:
Oct. 10, 2000 Practice sampling with Donna McCollum
Oct. 15, 2000 First sample
TBA Second Sample
TBA Third sample
Oct. 23, 2000 Class feedback to proposal
Nov. 6, 2000 Have completed sampling and calculated our data.
Nov. 8, 2000 Post our results
Nov. 16, 2000 Class feedback on data calculations and statistical methods.
Nov. 20, 2000 Revise results if necessary

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