Similarly, a recent "state of the science" assessment (Lewis et al., 1995) defined limnology as
the integrative study of inland waters. It encompasses the biological, chemical and physical phenomena, as well as all levels of organization extending from individual chemical reactions or adaptations of individual organisms to the analysis of entire ecosystems.
Nonetheless, many aquatic scientists, as well as the general public, associate the word limnology exclusively with the study of lakes (and reservoirs). There are historical reasons; organized studies of lakes using techniques of modern science began much earlier (late nineteenth century) than studies of flowing waters and wetlands.2 In addition, the discrete, semiclosed nature of lake basins, compared with the open, flowing nature of streams and the often diffuse boundaries of wetlands, makes it easier to view lakes as appropriate objects of scientific study. Lake studies have always been approached holistically to include physical, chemical, biological, and geological aspects, even though biologists conducted most of the early work.
In contrast, the physical, geological, chemical, and biological characteristics of streams have been studied primarily within separate disciplines (i.e., as separate fields of study)—hydrology, geomorphology, geochemistry, sanitary (environmental) engineering, public health biology, fisheries science. These studies generally were pursued in separate academic departments such as civil engineering, geography, geology, public health, biology, and fisheries. To a considerable extent, this fragmentation still exists today—to the extent that stream limnology as a distinct field within the broad field of limnology might be questioned. To be sure, academic lake limnology suffers from the same fragmentation, but it is still considered a discrete field.
Except for studies on wetland flora and fauna by botanists and zoologists, studies on wetlands are even more recent, especially in North America, and for the most part, comprehensive studies of wetlands as ecosystems are the product of the past 20 to 30 years.
This paper examines the various paradigms that have driven the fields and subdisciplines of limnology since its founding in the late nineteenth century. As described above, the subareas of limnology differ substantially in the length of time over which they have developed, and this has important implications concerning the driving paradigms.
Some ecological studies on wetlands predate the beginnings of modern science in the late eighteenth and early nineteenth century (see section of this paper on Wetlands for further details), but the prevailing attitude that wetlands are wastelands limited both scientific and public interest in these ecosystems until recent years.