A School of Natural Resources and Environment faculty member will contribute his expertise on diatoms to a $6 million research project funded by the U.S. Environmental Protection Agency (EPA). The Natural Resources Research Institute (NRRI) of the University of Minnesota, Duluth, will direct the project to develop and test environmental indicators for the coastal and near shore regions of the Great Lakes.
Eugene F. Stoermer, professor of natural resources, is among 27 researchers in the United States and Canada selected to participate in this initiative. Headed by NRRI Director Gerald Niemi, the project will identify, evaluate and recommend assessment tools for measuring the health of the Great Lakes. The ecological grant is the largest ever awarded by the EPAs Science to Achieve Results (STAR) research program.
The researchers will consider indicators in five major areas: water quality and diatoms, fish and macroinvertebrates, wetland vegetation, birds and amphibians, and chemical contaminants.
Stoermer will focus on diatoms, a group of algae found in most aquatic systems. He has spent more than 30 years investigating the ecology and biology of these microorganisms that serve as useful gauges of ecological change.
Among the most diverse groups of aquatic organisms, diatoms have adapted to various environments and form the base of most aquatic food chains. They are found in large lakes and oceans, shallow lakes and rivers, in desert soils, on the bellies of blue whales, and in the feathers of aquatic birds, Stoermer says. They are the most abundant organisms in the Great Lakes outside of bacteria.
During periods when conditions are not favorable for their growth, many diatoms settle to the bottom of lakes, slow their metabolisms, and live off stored fats and oils. At this time, they often become food for other bottom dwellers such as small fish and invertebrates. Large-scale changes in diatom communities generally precede large-scale changes in fish populations by approximately 3050 years, Stoermer noted in a 1998 report for the International Association for Great Lakes Research.
Because diatoms cell walls are made of silicon dioxide, their remains are preserved in lake sediments. Through the use of lead dating, scientists can study well-preserved records of changes in diatom communities over the last 200 yearsor in just the past year.
Samples taken from Great Lakes basins show modifications in diatom flora ranging from small changes in abundance to dramatic decreases and probably extinction of others, Stoermer wrote in the International Association report.
Paleolimnology has proven to be a very useful tool in understanding the history of human impacts on the Great Lakes, he says. We can measure ecological change in millions of diatoms per cubic centimeter. It would be virtually impossible to obtain a spatially and temporally integrated sample of organisms in any of the lakes in a given year by any other method.
Stoermer and his colleagues have used such sampling methods to determine the extent to which events such as phosphorous loading and exotic species invasions have altered the Great Lakes geochemistry and food chain.
These organisms also are useful for forecasting the effects of trends like eutrophication and climate change. By observing numbers and species of diatoms over a given period, past trends become apparent, Stoermer explains. The diatom studies of the STAR project will use time to reveal how conditions have changed or may change.
Stoermer is one of the relatively few scientists who do both basic and applied research with diatom communities. He has studied the paleontology and ecological processes of Russias Lake Baikal and other freshwater systems throughout the world. A U-M researcher and faculty member since 1965, he currently heads the Phytoplankton Laboratory for the Center for Great Lakes and Aquatic Sciences.
During the four-year EPA study, Niemi and his team will compile and test what they consider the best indicators to monitor the Great Lakes health. The Minnesota Sea Grant Program will distribute the researchers recommendations to the public and to management agencies across the Great Lakes.
STAR initiated the Estuarine and Great Lakes program to develop the sound science required to monitor coastal ecosystems in the United States. This grant is the first to be awarded to four focus areas that include the Great Lakes and the East, West and Gulf coasts.