Boulder High School seniors Anna Hermann, Kelly Lane, and Danielle Pite were invited to the prestigious 2008 Intel International Science and Engineering Fair for their team project “Didymosphenia geminata: The core question,” mentored by USGS Ecologist and INSTAAR affiliate Sarah Spaulding.
The students had previously won “First Place in Environmental Sciences” and “Best Team Award” at district and state level, respectively, in Colorado. They also presented their results at the 2008 Arctic Workshop at INSTAAR.
For their project, Hermann, Lane and Pite used sediments from an Alaskan lake to assemble a 785 year-long record of abundance and morphology of the diatom Didymosphenia geminata. Commonly known as didymo or rock snot, this species has invaded numerous waterways in North America, New Zealand, and elsewhere in recent decades, threatening aquatic ecosystems with its extensive stream-bed mats. There is little to no historical data, however, to establish whether similar invasions occurred in the past. The students’ record covered the years 1218-2003, with chronological control established by known dates of ash layers. Their results show that there has been no recent increase in abundance of Didymosphenia, however, two species were present in the Alaskan sediment record: D. geminata and D. clavaherculis. The students proposed that bloom-forming populations of D. geminata from around the world are morphologically similar to one another. Hermann, Lane and Pite plan to submit their results to a scientific journal for publication this summer.