Surviving winter hypoxia: behavioral adaptations of fishes in a northern Wisconsin winterkill lake
- 1) Center for Limnology and Department of Zoology, University of Wisconsin, 53706, Madison, WI, U.S.A.
- 2) Experimental Lake's Area, Freshwater Institute, Box 313, P9N 3X4, Kenora, Ontario, Canada
- 3) Research Center — King Hall, State University of New York, 13126, Oswego, NY, U.S.A.
Synopsis: Winterkill lakes often have a characteristic fish community, presumably composed of species able to survive winter hypoxia. Our research on a small winterkill lake in northern Wisconsin indicates that fishes common in winterkill lakes have behavioral adaptations for tolerating or avoiding winter hypoxia. We examined the distribution of fishes within the lake during one winter (December through May), and fish migrations into and out of the lake for two consecutive years. As DO within the lake declined in late fall, adult-sized fishes of four species, brook stickleback, finescale dace, redbelly dace, and fathead minnow, moved to the ice-water interface where DO levels were highest. Stickleback, and to a lesser extent, fathead minnows, also moved toward the more highly oxygenated water near the inlet. During the first year, young-of-the-year fishes of blacknose shiner, Iowa darter, redbelly dace, and fathead minnow, avoided hypoxic conditions by emigrating from the lake via the outlet stream in late fall and early winter while DO within the lake was still relatively high. Blacknose shiner, redbelly dace, and fathead minnow returned to the lake in spring. Almost no fishes were trapped leaving the lake in the second fall-winter season. Central mudminnows neither moved to the ice-water interface nor emigrated from the lake as DO dropped. Mudminnows survive winter hypoxia by breathing oxygen-containing bubbles trapped beneath the ice. These relatively simple behavioral adaptations allow fishes to survive or avoid hypoxic conditions lethal to other species and may help explain the consistency in fish communities of winterkill lakes.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - agronomie. sciences du sol et productions vegetales
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Aquatic Science
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics