An exploration of the direct and indirect effects of climatic warming on arctic lake ecosystems (NSF-OPP 1603302)

Project Leads: Phaedra Budy, Anne Giblin, Byron Crump, Jiming Jin Sarah Null
Graduate Students: Natasha Christman, Nick Barrett
Technicians: Gary Thiede, Peter Mackinnon, Sarah Messenger, Dan White, Daison Weedop, Ryan West, Tyler Arnold, Brecia Douglas

Overview: This proposed research will complete a multi-year, whole-lake warming manipulation, to quantify the effects of future climate change on lake ecosystems in the Arctic. In addition, regional climate and lake models will be coupled with biotic responses to better understand the sensitivity of lakes to changing atmospheric conditions. To accomplish this we will: 1) experimentally measure the effects of longer and warmer growing seasons on whole ecosystem production and community composition (e.g., from microbes to fish); 2) predict arctic lake temperatures with a coupled, lake-climate model. The model will use historical climate data and climate projections, and the results from the lake manipulation to integrate physical, climate, and biological response for surrounding lakes ranging in volume and depth. These efforts will allow better predictions of the effects of climatic warming at broader spatiotemporal scales and improve conservation prioritization and decision-making. The proposed research will substantially improve understanding of climate change effects on arctic lake ecosystems and the ability to more precisely predict lake ecosystem response to this change.

Intellectual Merit: Arctic lakes support trophic interactions, biological processes, and critical habitat at all trophic levels; however, climatic warming threatens to alter the structure and function of aquatic communities and overall system productivity. Arctic ecosystems are warming at some of the fastest rates observed on earth; arctic lakes specifically are experiencing more frequent years of warmer and deeper surface water. However, the ability to detect and quantify ecosystem effects and specific biological responses to these climatic changes has been primarily limited to non-mechanistic modeled scenarios and observational studies in uncontrolled environments. The proposed research will use a controlled whole-lake manipulation experiment to answer: How will warmer lake temperatures and extended growing season alter (1) lake ice coverage
and annual thermal regime; (2) abundance, activity, and diversity of primary and secondary producers; (3) fish vital rates, production, and dynamics; and (4) degree of carry-over across growing seasons and cumulative effects. Experimental results will be combined with long-term Arctic LTER data to inform a linked modeling system (coupled lake-climate model and integrated physical, climate, biological, and bioenergetic modeling) to answer: How will warmer lake temperatures and an extended growing season alter: (1) lake thermal regimes at regional scales, and (2) fish populations across lake types of the Arctic. This research will quantify lake thermal processes and lake-atmosphere feedbacks, provide more precise projections of lake horizontal and vertical temperature structures, and document and predict lake biota and ecosystem responses to changes in lake thermal condition over large spatial scales and under different climate scenarios.

Broader Impacts: By providing some of the first empirical evidence of how fundamental processes will actually change in the face of climate change, this research will also improve understanding of ecosystem service sustainability (e.g., subsistence fisheries). The project seeks to better understand: (1) how fish production will change as lakes warm, (2) whether current levels of harvest are sustainable given these changes, and accordingly (3) if there are local opportunities to increase harvest or if local populations at greater risk of over-harvest. Research findings will be distributed to Arctic LTER, management agencies (U.S. Fish & Wildlife, Alaska Dept. of Fish and Game), and underrepresented students and teachers. Additionally, interactive outreach presentations will be developed for Inupiat native communities annually at Camp Goonzhii, Arctic Village, and Kaktovik Marine Science Camp, in collaboration with USFWS. Results will be shared with the North Slope Borough Dept. of Wildlife Management and the ADFG. During this project, graduate students will be trained in experimentation, modeling, data analysis, and communication. Results will be also be disseminated through an interactive project website with access to real-time lake temperature data, preliminary results, and photographic blog/twitter
link. Arctic lakes can serve as indicator systems to characterize resilience and identify environmental thresholds, and our integrated modeling can be applied to other systems where climate change is happening more slowly and is more difficult to detect.

Publications

Klobucar, S.L., J.W. Gaeta, and P. Budy.. “2018. A changing menu in a changing climate: using experimental and long-term data to predict invertebrate prey biomass and availability in arctic lakes.,” Freshwater Biology 2018:1-13., v.1, 2018, p. 1-13. doi:10.1111/fwb.13162.

Zhu, L., J. Jin, and L. Tian. “Simulations of the impact of lakes on local and regional climate over the Tibetan Plateau.,” Atmosphere-Ocean, 2017. doi:DOI: 10.1080/07055900.2017.1401524. 

Zhang, Q., J. Jin, L. Zhu, and S. Lu. “Modelling of Water Surface Temperature of Three Lakes on the Tibetan Plateau using a Physically Based Lake Model.,” Atmosphere-Ocean, 2018. doi:https://doi.org/10.1080/07055900.2018.1474085