Water Resources Research Act Program

Details for Project ID 2016NH201B

Salt and Streams: Assessing ecological stress in New Hampshire watersheds at community, population, and molecular levels

Institute: New Hampshire
Year Established: 2016 Start Date: 2016-03-01 End Date: 2018-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $49,760

Principal Investigators: Amy Villamagna

Abstract: The impacts of thermal variability and salt loading on freshwater biota have garnered attention and study in northern states, but it remains unclear how thermal and salt stressors synergistically impact biota across the community, population and molecular levels. Traditionally, biotic response to water quality degradation is measured using broad-based community metrics and/or assessing populations of bio-indicator species (e.g., EPT). Rapid biological assessments examine community composition and the presence of indicator species to assess overall stress; however, these methods are largely reliant on the loss of individuals and/or species, which could have cascading effects on biodiversity and the ecological function of streams. To truly avert the loss of species and ecosystem function, we need to develop techniques that will provide an early-warning signal of ecosystems in jeopardy. At the molecular level, heat shock proteins (HSPs) have been used as a sub-lethal biomarker of stress, and hold great promise as an early-warning sign of ecosystems in peril. The expression of HSP70 as a sub-lethal biomarker of stress may help us understand how shifts in stream thermal and salt regimes may influence species distribution. Moreover, by examining HSP70 expression in a target species in conjunction with population and community-level assessments, we can evaluate the tolerance range for key species and their natural ability to acclimate to the presence of elevated stressors. We propose a multi-level approach in which biotic response at the community, population, and molecular levels are integrated to provide a comprehensive assessment of past, current, and future stress that cannot be achieved using at any single metric in isolation. By leveraging large (and existing) datasets that describe stream temperature and chemistry (LoVoTECS) and fish populations (NHFG) in NH, we can evaluate multi-level bio-indicators of stress and develop a Multi-level Thermal and Salt Stress (MTSS) Index and decision-framework that can be applied to inform watershed management, road deicing, and mitigation strategies. This project has several components: 1) field sampling of macroinvertebrates to provide community and population metrics of biotic response, 2) laboratory-based stress experiments to determine HSP induction thresholds for thermal-salt stress in two mayfly species, and 3) field sampling and HSP expression assays of mayfly nymphs from streams that span a thermal and salt gradient to determine the utility of HSPs as biomarkers of stress in wild populations of mayflies. The research proposed herein serves to benefit society as a whole by providing a novel and robust early-warning signal of ecological stress in our streams prior to loss of biodiversity. More specifically, this work will benefit NH Departments of Fish and Game, Environmental Services, and Transportation, US EPA, US FWS, municipal agencies, local watershed associations, and non-profit groups (e.g. Trout Unlimited) who represent public interest in maintaining water quality and aquatic biodiversity. We foresee that this research will be useful to stakeholders by providing a multi-level evaluation of stress that will help aid in the timely identification of at-risk stream biota. The creation of the MTSS Index can help prioritize watersheds that need immediate attention and protection.