Continental-Scale Projections of Potential Climate Change Effects on Small Lakes in the Contiguous U.S. Vol. 3 Effects of Climate Conditions on Fish Habitat

This study is concerned with the projection of climate change effects on lakes, especially small lakes with surface areas up to 10 kttr and depths up to 24 m in the cold regions of the contiguous U.s. In this study, we have chosen lake parameters which are most directly influenced by climate and which in turn have much influence on aquatic lifeforms, water quality and water uses. The first two parameters studied were lake water temperature (T) and dissolved oxygen (DO) concentration. They have been estimated for past (1961-1979) climate conditions (Vol. 1 of this report) and a projected 2xC02 climate scenario (Vol. 2). Subsequently fish habitat in lakes, as constrained by T and DO, has been studied herein. In this Volume 3 of the report, water temperature and DO criteria (limits) of survival and good-growth of three fish assemblages (cold-water, cool-water, and warmwater), and parameters that quantify fish habitat in lakes in response to T and DO limits are given. Fish habitat was simulated in 27 types of lakes at 209 geographic locations over the contiguous U.S. under different climate scenarios. It includes a. validation of fish habitat simulations against fish observations and a sensitivity analysisof simulated winter fish habitat to three DO survival limits.