Initially, the Lab of Ornithology was housed in the university's entomology and limnology department. Hutchinson expanded the field of limnology, especially in its ecological and biogeochemical aspects. Main fields of study in the valley include limnology, geology, and geography. The work yielded insights into biogeography and new data on high elevation limnology. Another type of aquatic system which falls within the study of limnology are estuaries. The limnology of reservoirs has many similarities to that of lakes of equivalent size. All of them are nevertheless of international importance not least for the limnology and biodiversity. This modified black-and-white Secchi disk is the standard disk now used in limnology (freshwater) investigations. Most of Hutchinson's contributions to American limnology came from research at Linsley Pond in Connecticut. It was here that Hutchinson discovered limnology, or the study of fresh waters. "Limnology and Oceanography&colon; Bulletin". Limnology and Oceanography Bulletin, 24&colon;5-10. He advocated the use of statistical and mathematical methods in limnology. People who study limnology are called limnologists. In 2009 he became director of the UW-Madison Center for Limnology.