About

Larry Crowder is the Edward F. Ricketts Provostial Professor of Marine Ecology and Conservation at Hopkins Marine Station, Stanford Doerr School of Sustainability, and a senior fellow at the Stanford Woods Institute for the Environment. He is also an Affiliated Faculty member at the Stanford Center for Ocean Solutions and a Professor by Courtesy in the Department of Biology. His research centers on predation and food web interactions, mechanisms underlying recruitment variation in fishes, population and food web modeling in conservation biology, and interdisciplinary approaches to marine conservation. Dr. Crowder has studied food web processes in both freshwater and marine ecosystems, utilizing observational, experimental, and modeling approaches to understand these interactions and improve management. He has led large interdisciplinary research projects such as the South Atlantic Bight Recruitment Experiment (SABRE), OBIS SEAMAP, and Project GLOBAL, and is involved in current projects including Dynamic Ocean Management in Costa Rica (DYNAMAR), Sea Turtle Research Experiment on the Thermal Corridor Hypothesis (STRETCH), and traits-based tools for fisheries management under climate change. His recent work focuses on marine conservation issues like bycatch, spatial ecological analysis, nutrients and hypoxia, sustainable seafood, ecosystem-based management, marine spatial planning, and governance. Dr. Crowder is an AAAS Fellow, received Duke University’s Scholar/Teacher of the Year award in 2008-2009, was recently named a National Geographic Explorer, and has received a lifetime achievement award from the International Sea Turtle Society.

Research topics

• Computer Science
• Political Science
• Environmental science
• Environmental resource management
• Ecology
• Sociology
• Biology
• Environmental planning
• Oceanography
• Engineering ethics
• Engineering
• Geography
• Business
• Finance

Selected publications

• Effects of Body Size and Environmental Region on the Nutritional Value of Small Pelagic Species in the California Current

  Fisheries Oceanography · 2026-05-17

  articleOpen access

  ABSTRACT We evaluated the effects of regional environment and body size on the nutritional traits of five small pelagic species differing in habitat use, feeding behavior, and importance as prey for top predators in the California Current Large Marine Ecosystem (CCLME). Northern anchovy ( Engraulis mordax ), bigfin lanternfish ( Symbolophorus californiensis ), market squid ( Doryteuthis opalescens ), and boreal clubhook squid ( Onychoteuthis borealijaponica ) were collected in the summer of 2021 in the northern and southern CCLME. Energy density (ED), lipid, and protein content (% wet weight) were calculated for each specimen via bomb calorimetry and proximate composition analysis. Energy values from the two methods were highly correlated. Bayesian linear modeling revealed that while environmental conditions (sea surface temperature, chlorophyll‐ a , and upwelling) differed significantly between northern and southern CCLME, nutritional value did not vary significantly by region—an effect that was consistent across species. Body size affected both mass‐specific and whole specimen nutritional value, but the direction and magnitude of the relationship varied by species. While ED and % lipid increased rapidly with size in bigfin lanternfish and moderately with size in boreal clubhook squid, it was relatively consistent across size for anchovy and market squid. Fishes were more variable in ED and % lipid than squids, while % protein was highly variable across all specimens and increased significantly with size only in boreal clubhook squid. Our results highlight the importance of assessing drivers of prey quality to predicting predator foraging and nutrient flows under climate change.

  PublisherDOI

• Promise or peril in a warming ocean? An emergent pathway leads North Pacific loggerhead sea turtles into the northern California Current System

  Frontiers in Marine Science · 2026-04-22

  articleOpen access

  Over recent decades, the eastern North Pacific Ocean (ENP) has undergone significant climate-driven change, characterized by rising sea surface temperatures (SSTs), a northward expansion of the North Pacific Transition Zone (NPTZ), and more frequent marine heatwaves. Juvenile North Pacific loggerhead sea turtles ( Caretta caretta ), a highly mobile species sensitive to environmental variability, have emerged as a sentinel species within the region. When North Pacific loggerheads migrate from the eastern subtropical gyre to coastal habitat, they do so offshore of the Baja California Peninsula, Mexico. Analysis of an extensive satellite tracking data set (n=285,1997–2023) revealed no prior observations of juveniles entering the colder, nutrient-rich waters of the northern California Current System (CCS). However, the gradual northward shift of loggerhead foraging habitat has been observed in parallel with an increasingly oligotrophic NPTZ. In 2024, four of 28 satellite-tracked individuals deviated from historic migratory routes and entered the northern CCS. To understand the physical mechanisms that enabled these novel movements, we integrated SST, chlorophyll-a concentrations, and surface current conditions experienced by these individuals and compared them to historical records within the region. During September-October 2024, these turtles reached 45°N latitude, where they encountered strong eastward flow within the North Pacific Current (NPC), thermally suitable conditions, and enhanced productivity. These conditions created a transient, high-latitude migratory corridor into the northern CCS. While three of these turtles benefited from reaching enhanced forage habitat in the California Current System, one likely suffered cold-stunning upon entry into suboptimal waters. The other 24 turtles remained south of the NPC, in the subtropical gyre. Our study represents the first confirmed use of a new, northern CCS migratory corridor by juvenile North Pacific loggerhead sea turtles. These findings expand on the conceptual framework of the ‘thermal corridor hypothesis,’ which suggests that sea turtles opportunistically exploit anomalously warm conditions to reach foraging habitats along the North American coast. They also emphasize the role of additional environmental drivers, such as advective current systems, in these movements. Under accelerated climate change, such transient pathways may become increasingly prevalent, with significant implications for conservation planning and fisheries management.

  PublisherDOI

• 24. Conclusion

  Open Book Publishers · 2025-01-30

  book-chapterOpen access1st authorCorresponding

  Larry B. Crowder is Edward Flanders Ricketts Professor of Marine Ecology and Conservation, Hopkins Marine Station, Stanford University. He started the first course in Marine Conservation in 1997 at Duke University Marine Lab and Co-Edited the first textbook in Marine Conservation in 2005 (Norse and Crowder. 2005. Marine Conservation Biology. Island Press, Washington, DC. This chapter outlines vision for global, transdisciplinary approach to designing pathways to solutions in marine conservation.

  PublisherOA PDFDOI

• Human-wildlife coexistence through the lens of fishermen’s knowledge and lived experience

  npj Ocean Sustainability · 2025-07-09 · 4 citations

  articleOpen accessSenior author

  Climate change-related shifts in marine resource availability and species behavior are increasing rates of human-wildlife conflict (HWC). Although this trend poses significant risks to both human livelihoods and conservation efforts, strategies to resolve HWC focus largely on ecological outcomes, overlooking key impacts and contributions of human resource users. Here, we draw on the case study of whale entanglement in the Dungeness crab (Metacarcinus magister) fishery in California, U.S.A. to demonstrate the promise of integrating – and the consequences of neglecting – the voice and expertise of fishing communities. Semi-structured interviews with 27 commercial fishermen across nine towns in California revealed the diverse sociocultural impacts of HWC – often converging on livelihood and identity losses – as well as fishermen’s potential role in addressing HWC as long-time experts in the marine ecosystem. Our findings highlight pathways for achieving human-wildlife coexistence, underscoring the need to engage the knowledge and lived experience of local communities affected by HWC.

  PublisherOA PDFDOI

• Captive rearing and breeding are unlikely to save China’s critically endangered sea turtles

  Nature Reviews Biodiversity · 2025-11-13

  articleCorresponding
  PublisherDOI

• Safe food: A human right amid climate change

  Science · 2025-09-11 · 1 citations

  letter
  PublisherDOI

•  A social-ecological study of a Costa Rica fishery through fisher local ecological knowledge and satellite tracking

  2025-03-26

  preprintOpen accessSenior author

  Local ecological knowledge (LEK) is increasingly being recognized as a valuable component of ecological modeling, including in the creation of species distribution models (SDMs). SDMs are used to make inferences about the distribution of suitable habitat for species of interest and can provide valuable information about the occurrence of these species. However, data and monitoring limitations can be especially pronounced in remote areas, creating a need for affordable, reliable, and timely information. In fisheries studies, incorporating LEK from fishers may be a valuable way to fill data gaps in predicting fish species occurrence over spatiotemporal scales and can be useful for marine spatial planning. In this study, we investigated the spatiotemporal and biophysical characteristics of a billfish fishery in Costa Rica through a mixed methods approach combining satellite tracking data of sailfish (Istiophorus platypterus) and blue marlin (Makaira nigricans) and sport fisher LEK elicited through semi-structured interviews and participatory mapping. To compare these two methods for understanding billfish distribution, we created SDMs using either satellite tag data or LEK participatory maps for billfish occurrences and examined the environmental profiles within the satellite tracking and participatory map locations. Overall, we found that although participatory mapping of fishing grounds is confined by distance to shore, the fisher-mapped sailfish and blue marlin niches provide valuable fine-scale near-shore data and overlap with several spatial and environmental features revealed by satellite tracking data. From this case study, we suggest important considerations when incorporating LEK and other ecological monitoring methods for ecological modeling and marine management. Our findings provide a social-ecological perspective of the Costa Rican billfish fishery while demonstrating the potential of fisher knowledge to help address data gaps and complement satellite tracking data in spatiotemporal modeling of economically and ecologically important billfish, with implications for data-poor fisheries worldwide.

  PublisherDOI

• Multi-decade northward shift of loggerhead sea turtle pelagic habitat as the eastern North Pacific Transition Zone becomes more oligotrophic

  Frontiers in Marine Science · 2025-01-22 · 8 citations

  articleOpen access

  The North Pacific Transition Zone (NPTZ) is known as a global marine hotspot for many endangered and commercially significant highly mobile marine species. In the last few decades, the region has undergone unprecedented physical and biological transformations in response to climate variability and change. Although it is anticipated that many highly mobile species will need to adapt and shift their distributions, current predictions have relied on short-term data sets or modeled simulations. This has left a critical gap in our understanding of long-term (decadal or longer) change and species’ responses within the NPTZ. Here, we integrate nearly 3 decades of satellite tracking data from a climate sentinel, the juvenile North Pacific loggerhead sea turtle ( Caretta caretta ), with concurrent observations of sea surface temperature (SST) and chlorophyll-a concentrations to examine higher trophic level response to climate-induced changes within the eastern bounds of the NPTZ. Between 1997–2024, the NPTZ has warmed by 1.6°C and experienced an approximately 19% decline in mean surface chlorophyll-a concentration, a proxy for reduced productivity, resulting in a 28% (1.65 million km 2 ) increase in total oligotrophic habitat in the eastern NPTZ. Over the same period, the average latitude of loggerhead sea turtle foraging habitat in the NPTZ has shifted northwards by 450–600 km. This represents a distributional shift rate of 116–200km/decade. In most years both the southern and northern range limits for the loggerhead turtle have shifted northward in tandem, indicating a habitat range shift rather than a range expansion. Our findings reveal significant physical and biological change to the NPTZ over the last quarter century and the first empirical evidence illustrating the substantial spatial response of a highly mobile megafaunal species. As the NPTZ continues to become more oligotrophic, these insights can provide vital information for dynamic conservation and management strategies within this critically important ecosystem.

  PublisherOA PDFDOI

• From Shorelines to Social Media: Mixed-Methods Insights into Urban Fishing Practices, Policy Gaps and Culture in the Digital Age

  2025-08-15

  articleOpen access

  Recreational and subsistence fishing are globally significant forms of marine resource use, contributing to food security, cultural identity, and social well-being across diverse coastal communities. Yet these non-commercial sectors are often overlooked in formal fisheries monitoring and governance. In California’s San Francisco Bay Area, non-commercial fishers represent a wide range of backgrounds and motivations, yet remain underrepresented in marine policy and management. Previous research has struggled to differentiate between different types of sport and subsistence fishing practices, especially among shore- and pier-based fishing communities. This study addresses these gaps by using a novel, mixed-methods approach (leveraging qualitative insight to contextualize and interpret scalable digital data), to analyze how different groups of non-commercial fishers are driven by nuanced motivations while exhibiting unique fishing practices and strategies. Drawing on semi-structured interviews and a database of ~40,000 social media posts (2014-2023), we document differences in behavior, knowledge, and meaning across regional recreational and subsistence fishing subcultures. Our results challenge the assumption that the activities of these non-commercial fishers are marginal or unstructured, revealing strategic species targeting, rich place-based knowledge, and complex adaptive responses to social and ecological change. In demonstrating the value of non-traditional data sources in documenting overlooked patterns of participation and adaptation, we advocate for marine resource management and policy approaches that recognize diverse user groups, foster inclusive participation, and support equitable coastal resource access.

  PublisherOA PDFDOI

• A framework for just seascape restoration

  npj Ocean Sustainability · 2025-02-11 · 3 citations

  articleOpen access

  Scientists engaging in active habitat restoration often lack guidance and training on how to justly engage with the communities that rely on these ecosystems. This perspective offers a framework with five key recommendations for just seascape restoration: knowledge coevolution, participatory process, equity, and consistent monitoring. Employing these principles will support successful, just seascape restoration and can be applied to restoration efforts across various habitats and scales including the ecoscape scale.

  PublisherOA PDFDOI

Frequent coauthors

• Elliott L. Hazen

  NOAA National Marine Fisheries Service Southwest Fisheries Science Center

  79 shared

• John N. Kittinger

  Arizona State University

  66 shared

• Elena M. Finkbeiner

  Conservation International

  58 shared

• Steven J. Bograd

  NOAA National Marine Fisheries Service Southwest Fisheries Science Center

  53 shared

• Dana K. Briscoe

  Cawthron Institute

  50 shared

• Benjamin S. Halpern

  University of California, Santa Barbara

  48 shared

• Timothy H. Frawley

  University of California, Santa Cruz

  45 shared

• Rebecca L. Lewison

  San Diego State University

  41 shared

Labs

• Crowder LabPI

  Crowder Lab Stanford University PhD Student Profiles

Education

• Ph.D., Marine Ecology and Conservation

  Stanford University

  1980

• M.S., Marine Biology

  University of California, Santa Barbara

  1975

• B.S., Marine Biology

  University of California, Santa Barbara

  1973

Awards & honors

• AAAS Fellow
• Duke University’s Scholar/Teacher of the year award in 2008-…
• National Geographic Explorer
• lifetime achievement award from the International Sea Turtle…