OREGON STATE UNIVERSITY
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Ocean ecosystems are experiencing significant and rapid impacts of climate change, yet the cascading effects on marine organisms are largely unknown and understudied. It is therefore critical to understand how rapid environmental change will impact the availability and quality of key prey species, and consequently how these changes will impact predator health and population resilience. The goal of the SAPPHIRE project is to identify and describe the impacts of environmental variation on the physiology of a crucial marine prey species (krill) and a model marine predator (blue whale). Since the project launched in 2023, we have been examining how changing ocean conditions affect the availability and quality of krill, and impact blue whale body condition, endocrinology (i.e., hormone levels), and foraging and reproductive effort.
Species resilience to climate change over shorter timescales will be determined by the fitness and fecundity of individuals mediated through behavioral and physiological response pathways. This project aims to describe the co-response of marine prey (krill) and predator (blue whale) health to environmental variation at both individual and population levels, enabling a comprehensive understanding of impacts on species fitness under climate change conditions. Our research takes place in the South Taranaki Bight region of Aotearoa New Zealand, which is home to an upwelling system that supports aggregations of krill and a unique population of blue whales that is present year-round (see the OBSIDIAN project). Over three years of data collection (2024-2026) we are using interdisciplinary methods that include controlled experiments on krill to assess their response to elevated temperature, surveys for blue whale occurrence paired with active acoustic assessment of krill availability, Unoccupied Aircraft System (UAS; “drone”) flights over whales to determine body condition and potential pregnancy, tissue biopsy sampling to quantify hormone levels, and passive acoustic monitoring to describe rates of foraging and reproductive calls by blue whales. Our broad objectives are to:
The first two SAPPHIRE field seasons in 2024 and 2025 reveal just how dynamic this ecosystem is, with each year presenting markedly different ocean conditions, krill availability, and blue whale observations.
Through the SAPPHIRE project, we aim to develop a framework for understanding the health impacts of environmental change on krill and blue whales, which can in turn inform management decisions based on relevant thresholds. Furthermore, the outputs of SAPPHIRE will be well-suited for the design and testing of dynamic management approaches. Finally, the SAPPHIRE project harnesses the iconic status of blue whales to inform society about the significant impacts of climate change on the world’s oceans, so that publicity and regulatory action based on this flagship species can enhance awareness and motivate behavioral change.
Blog posts:
Daily Diel Ins! Calling patterns of New Zealand blue whales
The blues are back in town: recap of the 2025 SAPPHIRE field season
Burning krillories: determining krill caloric content in New Zealand's South Taranaki Bight
Learning from the unexpected: the first field season of the SAPPHIRE project
It's getting hot in here: studying the impacts of marine heatwaves on krill, life-blood of the ocean
Phases and feelings of the scientific journey
Blue whales, krill, and climate change: introducing the SAPPHIRE project
Collaborators:
New Zealand Department of Conservation
K. Lisa Yang Center for Conservation Bioacoustics, Cornell University
Cetacean Conservation Genomics Laboratory, Oregon State University
Dr. Phil Sutton, Earth Sciences New Zealand
Dr. Svenja Halfter, Earth Sciences New Zealand
Dr. Sarah Bury, Earth Sciences New Zealand
Dr. Emma Carroll, University of Auckland
Dr. Rochelle Constantine, University of Auckland
Dr. Kathleen Hunt, Oregon State University
Dr. Nick Kellar, NOAA Southwest Fisheries Science Center
Dr. Nicholas Wolff, The Nature Conservancy
Funding:
The SAPPHIRE project is supported in part by the National Geographic and Rolex Perpetual Planet Ocean Expeditions.
Publications:
Barlow DR, Klinck H, Torres LG (2026). Inter- and intra-annual variation in the frequency of blue whale songs in Aotearoa New Zealand. JASA Express Letters 5(12): 1-8. https://doi.org/10.1121/10.0041948
Prior publications on New Zealand blue whales (Project OBSIDIAN):
Blue whales are globally distributed, with distinct populations that feed in productive coastal regions worldwide. Comparing blue whale populations between different regions can therefore shed light on how different life history adaptations to ecosystem function may influence population resilience to environmental change. We are therefore comparing ecosystem characteristics and blue whale morphology between foraging grounds. This comparative aspect of the SAPPHIRE project is a pilot phase that uses data already collected. Specifically, we are comparing the oceanography of three blue whale foraging grounds: (1) Monterey Bay, USA, (2) South Taranaki Bight, Aotearoa New Zealand, and (3) Corcovado Gulf, Chile. Additionally, we are using drone images to compare the morphology and body condition of the blue whale populations that feed in each of these three regions.
Our findings to-date illustrate how these three blue whale populations are “shaped by their environment”, with morphological differences that reflect differences in the annual cycles of upwelling and productivity on the three foraging grounds.
New data collection efforts will allow for more comprehensive comparisons between regions and blue whale populations, which in turn may shed light on the resilience or vulnerability of these populations to environmental change.
Collaborators:
Dr. Will Oestreich, Monterey Bay Aquarium Research Institute
Dr. John Ryan, Monterey Bay Aquarium Research Institute
Dr. Gustavo Chiang, Universidad Andrés Bello
Dr. Matt Leslie, United States Geological Survey
Dr. John Durban, Oregon State University
Dr. Michael Moore, Woods Hole Oceanographic Institute
Dr. Jeremy Goldbogen, Stanford University
Dr. Dave Johnston, Duke University
Publications:
Barlow, D. R., Bierlich, K. C., Oestreich, W. K., Chiang, G., Durban, J. W., Goldbogen, J. A., Johnston, D. W., Leslie, M. S., Moore, M. J., Ryan, J. P. & Torres, L. G. (2023). Shaped by their environment: variation in blue whale morphology across three productive coastal ecosystems. Integrative Organismal Biology, 5(1), obad039. https://doi.org/10.1093/iob/obad039
Funding:
Orange County Community Foundation
