Front Entrance of Ruth Patrick Science and Education Center

RPSEC Environmental Science Award 2009

Ruth Patrick Science Education Center

Congratulations to Nathaniel D. Fletcher, recipient of the 2009 Ruth Patrick Science and Education Center Environmental Science Award at the 2009 Central Savannah River Area Science and Engineering Fair

Nathaniel submitted his project from Kennedy Middle School in Aiken, SC.

2009 Nathaniel Fletcher

Title of project

Effects of Urbanization on Stream Macroinvertebrates


The purpose of my project is to determine how urbanization influences aquatic macroinvertebrate populations and communities by comparing abundance and community composition between an urban stream and a reference stream. I hypothesize that if a stream is disturbed by urbanization, then macroinvertebrate diversity will be lower than in a less disturbed reference stream. Also abundance of sensitive taxa such as mayflies, stoneflies, and caddisflies will be lower if a stream is disturbed.

I placed samplers in an urban stream (Dibble Road Creek) and a reference stream (Upper Three Runs). The samplers were three sticks of similar size bundled together. Ten samplers were hung in mid-water and 10 placed on the bottom in each stream. I then waited four weeks to collect them to give macroinvertebrates plenty of time to colonize my samplers. After collecting the samplers I picked off all of the macroinvertebrates that were on them and identified them.

Nathaniel working with samplers

The urban stream was severely eroded and had unstable banks and bottom. Many samplers were buried by sand here, but no samplers were buried in Upper Three Runs. Diversity was much lower in the urban stream. The abundance of sensitive taxa was also lower in the urban stream. Sensitive taxa were common in Upper Three Runs, but no mayflies, stoneflies, or caddisflies were on samplers from the urban stream. Within the reference stream I saw effects of sampler position and complex interactions between predator and prey taxa. I conclude that urbanization has had devastating effects on Dibble Road Creek.