December 15, 2017
Dam realities: Scientists in the Division of Biology explore how small dams in Kansas streams disrupt native fishes
By James Guikema
As many as 2 million small dams — less than 25 feet high — block streams throughout Kansas and the U.S., and researchers in K-State's Division of Biology are studying how these dams affect the Kansas aquatic system.
Jane Fencl, Martha Mather, Joe Smith and Sean Hitchman recently published "The Blind Men and the Elephant Examine Biodiversity at Low-Head Dams: Are We All Dealing with the Same Dam Reality?" in the journal Ecosphere. Physical barriers, such as large hydropower dams, and common small low-head dams block the natural river and stream flows — which alter the habitat used by fish and other aquatic organisms.
The researchers spent the last several years evaluating the scientific generality of different approaches to the low-head dam fish biodiversity problem. They collected data in the Neosho River. According to the researchers, many of these small dams are aging and are at the end of their "lives." Repair or removal will be both critical and complicated.
The team concluded that the absence of a holistic perspective about dam-biodiversity research limits scientific understanding across studies, and, as a result, impedes effective conservation. Specifically, in one common approach — a comparison of sites upstream versus downstream of dams — upstream dam impoundments had fewer fish species and a much lower abundance of fishes than free-flowing sites immediately below dams, indicating a large dam impact. However, in another common research approach — a comparison of dammed versus undammed sites — free-flowing sites immediately below dams had similar abundances and richness of fishes to free-flowing sites far from dams, indicating a smaller dam impact. These comparisons, made at the same dams, illustrate that how the dam-biodiversity problem was framed altered scientific conclusions and created different dam realities.
Divergent spatial and taxonomic approaches to examining biodiversity at dams can produce conflicting science-based conclusions about the same dam impacts.
"The metaphor of the blind men and the elephant illustrates this problem," Mather said. "When a group of blind men encountered an elephant for the first time, each blind man sought to understand what this unknown entity was by touching isolated parts like the trunk or a leg. The blind men failed to understand, agree upon, and accurately generalize the larger issue, 'the whole elephant' from the smaller samples, 'body parts' because they were unaware that they had examined different parts of the same complex whole."
If individual dam biodiversity researchers use different conceptualizations to examine the same complex dam disturbance, the same lack of generality may occur for this important environmental problem. This coordinated and holistic perspective on ecological dam research can increase science-based generalizations across individual research studies that will enhance the protection, sustainability, and restoration of fragmented aquatic ecosystems.
This research was supported by a State Wildlife Grant from the U.S. Fish and Wildlife Service and the Kansas Department of Wildlife, Parks and Tourism administered through the Kansas Cooperative Fish and Wildlife Research Unit — a collaboration among Kansas State University, the U.S. Geological Survey, U.S. Fish and Wildlife Service, Kansas Department of Wildlife, Parks and Tourism, and the Wildlife Management Institute. This research benefitted from interactions with Kansas conservation professionals, Eric Johnson, Westar Energy; Jason Luginbill, U.S. Fish and Wildlife Service; and Jordan Hofmeier, Kansas Department of Wildlife, Parks and Tourism.