RAPID: Time-Sensitive Assessment of Hydrothermal Vent Influence on Reproductive Ecology of Antarctic Krill

Antarctic krill are a vital component of the Southern Ocean ecosystem, supporting whales, seals, penguins, fish, and seabirds, while sustaining the region’s largest fishery. Yet the habitats that support successful krill reproduction remain poorly understood, limiting science-based management in a rapidly changing and increasingly fished region. This project will test whether hydrothermal vent systems in the Bransfield Strait provide essential mineral resources to reproductive female krill. Because iron, manganese, and zinc support egg production, embryo development, and core cellular processes, vent-influenced habitats may represent overlooked reproductive resources in the otherwise mineral-limited Southern Ocean. Results will advance understanding of Antarctic food webs and deep-sea–pelagic connections, inform conservation and fishery management through the Commission for the Conservation of Antarctic Marine Living Resources, and train an early-career researcher and undergraduate student in polar marine science. This project will leverage an expedition aboard the German research vessel, RV Polarstern, to investigate whether hydrothermal vent-influenced regions contribute to mineral provisioning and reproductive success in Antarctic krill, Euphausia superba. Gravid females will be collected across the Bransfield Strait, Gerlache Strait, northwest Weddell Sea, and Elephant Island regions using towed nets. Shipboard egg-production experiments will quantify batch size, embryo number, and embryo traits, while frozen females and embryos will be analyzed at Oregon State University for trace metals, lipid and protein content, and stable isotopes. Concentrations of iron, Manganese, and Zinc in ovaries, hepatopancreas, muscle, and embryos will be compared among regions using mixed-effects models, and reproductive output will be modeled as a function of ovarian trace-metal concentrations, female size, and region. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.