I study ecological processes and biogeographical patterns, in the context of human impacts. While I focus on oceans, I often test concepts developed on land in marine systems; I think working across realms helps to understand the universality of ecological theories and conservation approaches. The core themes of my research program are described below.
Climate biogeography
Species around the globe are shifting their ranges in response to climate change, reshuffling ecosystems and challenging paradigms of natural management. Yet species’ range shifts are highly variable, perhaps because many ecological and environmental processes besides climate also influence species distributions. Without understanding these other processes and how they interact with one another and with climate, it’s difficult to predict range shifts and make management recommendations. I work to advance our mechanistic understanding of processes that govern species distributions in the Anthropocene, and consequently, our ability to forecast those distributions. Some specific past, present, and future research topics in this vein include:
- The degree to which range edges of temperate marine fishes are tracking temperature change (Fredston-Hermann et al. 2020, Fredston et al. 2021)
- Whether marine biogeographic boundaries limit ranges via dispersal limitation or post-dispersal selection, and the consequences for range shifts
- Advancing methods for ecological forecasting of range-shifting species, using both statistical and mechanistic modeling approaches
- How marine protected areas can be designed to accommodate future range-shifting species (Fredston-Hermann et al. 2018)
Cumulative human impacts on marine ecosystems
Climate change may transform ecosystems through not only the “press” of gradual warming but also the “pulse” of extreme events like heatwaves. I led research finding that demersal marine fish communities do not exhibit a consistent response to marine heatwaves (Fredston et al. 2023)–surprising, given the dramatic effects marine heatwaves have had in shallower ecosystems such as coral reefs and kelp forests. Next, I plan to explore the mechanisms driving ecological responses to marine heatwaves to understand why some heatwaves are much more damaging than others.
While my research program centers on climate change, sustainable oceans require managing other human impacts, including runoff and fishing. Runoff – the direct influx of sediments, nutrients, and other forms of pollution carried to coastal oceans from rivers – directly threatens sensitive habitats that are crucial to biodiversity conservation, like coral reefs and seagrass beds. I have participated in numerous collaborations that worked to provide operational tools for land-sea management, particularly in data-limited settings (Brown et al. 2019, Fredston-Hermann et al. 2016).
Well-managed fisheries could provide protein with a low greenhouse gas footprint to billions of people and support livelihoods in countless coastal communities. Unfortunately, many fisheries in the world are associated with problematic social or ecological outcomes – or both. I engage with fisheries both through primary research and through collaboration and outreach with stakeholders. For example, I collaborated with economists to demonstrate that the biogeographical dynamics of high-value fishery target species like tunas influence whether it is profitable to harvest them to extinction (Burgess et al. 2017).
To meet planetary challenges, we need to – as Dr. Julia Stewart Lowndes and friends put it – do “better science in less time”. I work to implement best practices for open and reproducible science in my research. Beyond my lab, I’ve contributed extensively to collaborations aimed at making it easier for my field to do impactful science, from demystifying climate scenarios for marine ecology audiences (Burgess et al. 2023) to building a data infrastructure that standardized dozens of publicly-available bottom trawl surveys from around the world (Maureaud et al. 2024). I’ve also written about the challenges and opportunities that the open science movement presents to the marine sciences, especially for early-career scientists (Fredston and Lowndes 2024).
Jordana Sevigny joined the Fredston Lab in 2023 as a PhD student in Ocean Sciences. Prior to moving to Santa Cruz, Jordana worked in Seattle in several labs researching transmissible cancer in bivalves, evolution and ecology of microbes, and alpine wildflower ecology and citizen science. Jordana holds a B.S. in Biology with an emphasis in Ecology from University of Washington. In the Fredston Lab, Jordana’s research centers on mechanistic modeling of marine invertebrate species’ dispersion and range edge dynamics. Outside of lab, Jordana enjoys many hobbies including kayaking, camping, reading, and crafting. Read more of her research on Jordana’s Google Scholar page.
Theodore Tran is a PhD student and a National Science Foundation Graduate Research Fellow interested in investigating questions of ecology among sharks and other large, mobile marine predators. He earned in BS in Marine Biology at San Jose University. He aims to integrate and synthesize interdisciplinary methods to establish factors and trends in migratory patterns and habitat use in light of anthropogenic impacts and climate change.