Johan F. Gottgens
Associate Professor
Department of Earth, Ecological and Environmental Sciences
419-530-8451 (office), -4597 (lab)
jgottge@uoft02.utoledo.edu
My teaching and research focus on
aquatic ecology, the study of the relationships among and between aquatic organisms and their environment. Over the years, aquatic ecology has grown from a basic science to an applied discipline which is increasingly called upon to help understand and solve pollution problems impacting our lakes, rivers, and wetlands. As a result, modern aquatic ecology combines a traditional biological orientation with engineering, hydrology, geology, environmental chemistry, and other disciplines.Students in my program use this approach in their research projects. Field sites include Lake Erie, Maumee Bay, Great Lakes’ wetlands, and the wetlands of the Brazilian Pantanal. Projects may be carried out on the main campus or at the Lake Erie Center, located on the Maumee Bay shoreline. Since 1995, I have also supervised research in South America on mercury pollution and succession in riparian forests. My lab is currently pursuing three research areas; (1) paleolimnological approaches to restoration, (2) pulse stability in wetlands, and (3) the cycling and accumulation of mercury in the aquatic environment.
Paleolimnological Approaches to Restoration
To understand the response of lakes, rivers and wetlands to anthropogenic actions requires long-term records of environmental data. Because such historical data are usually absent, we focus on the stratigraphic analysis of sedimentary records and the mechanisms that can modify those records (i.e., paleolimnology). Students and I have published paleolimnological research on lake and wetland responses to water-level manipulations, residential development in the watershed, long-term loading of agricultural non-point pollution, dam failures in reservoirs, and long-term contamination with toxic substances. This work provides great opportunities for students to get an appreciation for the links among different scientific disciplines.
Pulse Stability in Lakes and Wetlands
Succession in aquatic ecosystems is often controlled by the occurrence of periodic perturbations, such as fluctuating water levels, drought, fire, grazing, or tides. These perturbations generally remove organic matter from the system and liberate inorganic nutrients. As such, they help maintain such ecosystems at an intermediate stage in their successional development. Water managers, however, generally aim to eliminate these periodic disturbances, because they tend to interfere with the use of aquatic habitat for water supply, navigation, recreation, and aquaculture. We are interested in testing hypotheses relative to the long-term impact of eliminating or altering such a pattern of pulsed stability in temperate zone and neotropical lakes and wetlands.
Cycling and Accumulation of Mercury in the Aquatic Environment
As an extension of our research in paleolimnology, we study mercury accumulation in sediment cores and its transfer along food webs. Mercury is a strong neurotoxin linked to reproductive failure and high mortality. Food web transfer is important in the accumulation of mercury with the highest levels occurring in the longer-lived species at the upper trophic levels. Health concerns from dietary mercury intake have resulted in sweeping advisories against fish consumption, including a statewide advisory in Ohio. We work in the temperate zone and the Brazilian tropics, where mercury release from gold mining may contribute to ecosystem damage and threaten biodiversity.