Current and future hydrologic variability is a major driver underlying large-scale management and modification of inland waters and river systems. In a climate-altered future, identifying and implementing management actions that mitigate anticipated flow regime extremes will be an important component of climate adaptation strategies. These concerns will be particularly focused on extreme flows (floods and droughts) that have ecological, social, and economic importance, and whose impacts are inversely proportion to their frequency. Climate warming is expected to increase the frequency of extreme precipitation. It is critical for natural resources conservation that responses to these risks incorporate ‘green’ infrastructure which potentially benefit both ecosystems and human infrastructure
Cold-water fish are disappearing from many midwestern lakes as they warm. This loss is due to a combination of de-oxygenation of the deep waters with heating of the surface waters. Together, these climate-driven changes squeeze the depth distribution of fish that require cold, well-oxygenated water, sometimes eliminating their habitat entirely. We will investigate where this combination of factors has likely caused extirpation of cold-water fishes, and where future warming is most likely to eliminate more populations. In addition to hydrodynamic modeling, we are partnering with genomics experts to assess selection on functional genes associated with surviving temperature or oxygen challenges. The goals of this project are to: Manage cold-water lake fishes. Manage fish species of special concern in the state. Guide pre-emptive efforts to prioritize sites for management interventions
Water temperatures are warming in lakes and streams, resulting in the loss of many native fish. Given clear passage, coldwater stream fishes can take refuge upstream when larger streams become too warm. Likewise, many Midwestern lakes “thermally stratify” resulting in warmer waters on top of deeper, cooler waters. Many of these lakes are connected to threatened streams. To date, assessments of the effects of climate change on fish have mostly ignored lakes, and focused instead on streams. Because surface waters represent a network of habitats, an integrated assessment of stream and lake temperatures under climate change is necessary for decision-making. This work informed the preservation of lake/stream linkages, prioritization restoration strategies, and stocking efforts for sport fish. This project employed state-of-the-science methods to model historical and future thermal habitat for nearly ten thousand lakes
The Driftless Region is blessed with an exceptional coldwater fishery (native brook trout and non-native brown trout). Based on statistical modeling, it has been predicted that over the next 50 years brook trout will virtually disappear from the region and areal extent of brown trout will decrease significantly. However, these predictions do not account for potentially significant increases in groundwater recharge and hence in baseflow as a result of likely increases in fall through spring precipitation and potential decreases in winter frost. Nor do they account for the fact that baseflow in the Driftless Region is due mainly to thousands of springs, many of which are supply streams with relatively small drainage areas (e.g., less than 10 km2). Empirical evidence suggests that flow from these springs as well as from in-channel seeps persists at anomalously high rates during droughts, such as the severe drought of 2012
The goal of this project was to identify how winter severity, snowpack, and lake ice could change through the mid- and late-21st century, and how species such as the white-tailed deer and mallard duck will respond. Because currently available climate data is at too coarse a scale to provide information on future conditions for the Great Lakes, researchers transformed these models from a global-scale to a regional-scale. Using these models, researchers found that the region could experience substantial warming, reduced lake ice cover, and increased precipitation, with more precipitation falling as rain than snow, among other changes.
Stream data for the northeastern U.S. are needed to enable managers to understand baseline conditions, historic trends, and future projections of the impacts of climate change on stream temperature and flow, and in turn on aquatic species in freshwater ecosystems. This project developed a coordinated, multi-agency regional stream temperature framework and database for New England (ME, VT, NH, CT, RI, MA) and the Great Lakes States (MN, WI, IL, MI, IN, OH, PA, NY) by building a community around the efforts of this study. These efforts included 1) compiling metadata about existing or historic stream temperature monitoring locations and networks, 2) developing a web-based decision-support mapping system to display, integrate, and share the collected information, and 3) developing data system capabilities that integrate stream temperature data from several data sources
To integrate results of a current condition habitat assessment of stream habitats that accounts for fish response to human land use, water quality impairment, and fragmentation by dams with estimates of future stream habitats that may change with climate. This was accomplished by 1) Characterization of the current condition of stream fish habitats throughout the NE CASC region based on responses of target fish species to a diverse set of landscape-scale disturbances; 2) Identification of stream reaches predicted to change with climate and likely to change distributions of target fish species throughout the region; and 3) Development of a spatially-explicit web-based decision support viewer (FishTail) showing measures of current landscape condition along with estimates of changes in habitat that may occur with changes in climate. Tools and Products FishTail https://ccviewer.wim.usgs