Research Projects

Current · University of Minnesota

Oxythermal Tolerance of Laurentian Coregonid Fishes

Cisco (Coregonus artedi) and lake whitefish (Coregonus clupeaformis) are ecologically and economically important coldwater species throughout the Great Lakes. As environmental change drives warmer water temperatures and more frequent hypoxic events, understanding the oxythermal limits of these species, and whether those limits vary across ecotypes, is critical for predicting population responses and informing management decisions.

This project investigates differences in oxythermal tolerance among embryos and larvae of multiple coregonid species and ecotypes. By characterizing the physiological performance curves and tolerance boundaries of early life stages, we aim to construct physiologically guided abundance models that can forecast how specific populations will respond to changing thermal regimes.

Funded by the GLFC and the ENTRF (Total Awarded: $945K) · PI: Dr. Gretchen Hansen · Role: Lead Researcher

Dissertation Work · University of California, Davis

Fundamental & Ecological Thermal Physiology of Chinook Salmon

Chinook salmon (Oncorhynchus tshawytscha) exhibit remarkable diversity across California river systems — different seasonal runs, different thermal histories, and increasingly different fates under climate change. My dissertation addressed a fundamental question: are these populations physiologically distinct in ways that reflect local adaptation to their thermal environments?

I designed and conducted one of the largest metabolic experiments ever performed on teleost fishes, measuring aerobic scope, thermal performance curves, and critical thermal maxima across eight hatchery populations spanning the western United States. This work demonstrated clear interpopulation variation in thermal physiology and provided evidence for local adaptation.

This work yielded three published papers, a book chapter, and an invited talk at NOAA's Groundfish Seminar Series.

Funded by the EPA, SWRCB, USGS (Total Awarded: $444K) · PI: Dr. Nann Fangue · Role: Lead Researcher

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Current · University of California, Davis

Fish-Safe Hydropower Turbine

Hydropower is a critical component of renewable energy infrastructure, but conventional turbines impose significant sub-lethal and lethal injury on fish passing through them. A novel fish-safe turbine design offers the potential to dramatically reduce these impacts but its effects on fish physiology have not been rigorously tested.

This project uses white sturgeon (Acipenser transmontanus) as a model species to quantify acute injury and mortality rates from turbine passage, and to evaluate the sub-lethal physiological consequences that persist in fish that survive. Study 1 is now published; Study 2 is in progress.

Funded by the US DOE (Total Awarded $875K) · PIs: Drs. Nann Fangue & Kenneth Zillig · Role: Lead Researcher, Grant Author

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McMurdo Station, Antarctica

Global Change Biology of Antarctic Fishes

Antarctic notothenioid fishes are among the most thermally sensitive vertebrates on Earth due to millions of years of evolution in one of the most stable cold-water environments on the planet. As the Southern Ocean warms at an accelerating rate, these species face an unprecedented physiological challenge.

Working at McMurdo Station under the supervision of Dr. Anne Todgham (UC Davis), I studied the combined effects of ocean warming and acidification on juvenile notothenioids including Trematomus bernacchii and T. pennellii. This work documented differential temperature preferences, metabolic responses, and behavioral indicators of niche differentiation between species; providing a framework for understanding how Antarctic fish communities may respond to climate change.

Funded by the USAP · PI: Dr. Anne Todgham · Role: Researcher

Current · University of California, Davis

Effects of Feed Restriction on Thermal Performance

How does nutritional stress interact with thermal stress to affect salmon physiology and survival? This is a critical and understudied question for conservation management.

This three-year study combines a 14-week laboratory experiment with an 8-week field study to quantify how feed rationing affects metabolic thermal performance in Chinook salmon and whether poor performance among wild salmon populations may be a consequence of food limitations. Two manuscripts are in progress.

Funded by the SWRCB (Total Awarded: $750K) · PI: Dr. Nann Fangue · Role: Lead Researcher

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Current · University of California, Davis

Thermal Physiology of the Unarmored Threespine Stickleback

The unarmored threespine stickleback (Gasterosteus aculeatus williamsoni) is a federally endangered subspecies found in only a handful of streams in southern California — one of the rarest fish in North America. Unlike its armored counterparts, this subspecies has reduced lateral plates and an extremely restricted range, leaving it acutely vulnerable to altered river management and climate change.

This project characterizes thermal performance across embryos, larvae, juveniles, and adults, profiling multiple life stages to identify which are most thermally sensitive and how different traits respond to temperature. By building a comprehensive physiological picture of the subspecies, the work aims to clarify how changes in river management, including altered flow regimes and temperature profiles, may affect its persistence.

The project builds directly on the fundamental vs. ecological thermal physiology framework developed in the Chinook salmon studies, applying those methods to a critically endangered subspecies where physiological data can directly inform regulatory decisions and habitat restoration priorities.

Funded by the LACSD (Total Awarded: $510K) · PI: Nann Fangue · Role: Lead Researcher

Methods Development · University of California, Davis

Laser-Timed Burst Swimming Tunnel

Burst swimming performance, characterized as short, explosive anaerobic locomotion, is critical for predator escape and prey capture in fish. Yet methods for measuring it precisely and at scale have been lacking. I designed, built, and tested a Raspberry Pi-powered laser-timed burst swimming tunnel that allows rapid, precise quantification of multiple anaerobic performance traits across species and temperatures.

This system has since been applied to study the burst swimming of juvenile Chinook salmon, largemouth bass, rainbow trout, white sturgeon and green sturgeon.

PI: Dr. Nann Fangue · Role: Device Engineer and Researcher