Connecticut College News
Botany professor makes big impact with microorganism research03/29/2012
Professor Peter Siver wrote the cover article for the March 2012 edition of Freshwater Biology with Anne M. Lott '91, a research associate in the Botany department. The cover photo, which depicts a cell of Mallomonas lychenensis, was taken by Siver with a scanning electron microscope.
Professor Peter Siver studies some of the world's smallest organisms, and his recent accomplishments are making a big impact in an important scientific field. Siver, the Charles and Sarah P. Becker '27 Professor of Botany and director of the Environmental Studies Program at Connecticut College, studies the chrysophytes and diatoms founds in lakes, oceans and other water sources. Siver's work with these photosynthetic microorganisms is helping scientists understand evolution and climate change and has even been used to solve murder mysteries. In addition to recently winning a $379,756 National Science Foundation grant for ancient climate change research, Siver is the lead author on a new book, "The Freshwater Diatom Flora of Waterbodies on the Atlantic Coastal Plain," and published a March 2012 cover article in the journal Freshwater Biology with Anne M. Lott '91, a research associate in the Botany department. And, to top it all off, Danish scientist Jorgen Kristiansen and his Czech Republic colleague Yvonne Nemcova named a South African chrysophyte - Mallomonas siveri - in Siver's honor. Diatoms, according to Siver, are an underappreciated microorganism. "They, along with other photosynthetic protists, are responsible for half of all photosynthesis and, therefore, half of all of the oxygen we breathe," Siver said. He explained that there are numerous kinds of diatoms, which all thrive under different conditions. They have glass shells, which remain in the sediment at the bottom of a waterbody, making them ideal for tracking changes in aquatic systems. When scientists take cores from bodies of water and implement geo-dating techniques, they can use the diatoms they find in the core sample to estimate the acidity and nutrient levels of that waterbody during a given time period. For "The Freshwater Flora of Waterbodies on the Atlantic Coastal Plain," which Siver co-wrote with Paul B. Hamilton, Siver and his team studied Carolina Bays, shallow crater-like depressions scattered along the Atlantic coast. "No one had looked at the diatom flora there before," said Siver. The book, which is part of a series about diatoms in North America, includes 2,331 photographs of diatoms, all of which were taken in Connecticut College labs. Siver's journal article, "Biogeographic patterns in scaled chrysophytes from the east coast of North America," appeared on the cover of the March 2012 edition. As its title suggests, the article focuses on chrysophytes, algae found primarily in fresh water. Siver and Lott recruited Connecticut College students to aid them with their research, taking the students to locations along the Eastern seaboard to examine the various chrysophytes. - By Laura Marenghi '12