Oral Presentations and Performances: Session III
Project Type
Presentation
Project Funding and Affiliations
Oregon State University (CEOAS), National Science Foundation
Faculty Mentor’s Full Name
Andrew Whiteley
Faculty Mentor’s Department
Biological Sciences
Additional Mentor
Kim Bernard, Matthew Church
Abstract / Artist's Statement
Antarctic krill, Euphausia superba (referred to as "krill" hereafter), are vital to the Antarctic pelagic ecosystem. They serve as primary consumers of phytoplankton, a key food source for apex predators such as blue whales, and play a significant role in carbon sequestration in the Southern Ocean. Additionally, krill are economically important, as they are the target of the largest fishery in the Southern Ocean. However, the Antarctic Peninsula (AP), one of the fastest warming regions in the world, is experiencing substantial changes in its pelagic ecosystem. The impact of this warming on krill population dynamics and reproductive success remains unclear. To address this, we analyzed historical krill population data from the AP (January 1999–2011, Palmer Antarctica Long Term Ecological Research) to examine interannual variability in the timing and duration of the spawning season and to identify environmental drivers. We also developed a pregnancy index to quickly assess the sexual development stage of female krill in the field. Our findings showed that both the timing of spawning initiation and the spawning season duration varied annually. Linear mixed-effects models indicated that neither could be directly explained by environmental conditions at the time of sampling. It is likely that oceanographic and climatological conditions in the months preceding the spawning season may significantly influence the reproductive output of mature female krill. These factors will be incorporated into future models, with results shared with the SCAR Krill Expert Group to enhance krill fishery management.
Category
Life Sciences
Exploring Environmental Drivers of Antarctic Krill Reproductive Output
UC 333
Antarctic krill, Euphausia superba (referred to as "krill" hereafter), are vital to the Antarctic pelagic ecosystem. They serve as primary consumers of phytoplankton, a key food source for apex predators such as blue whales, and play a significant role in carbon sequestration in the Southern Ocean. Additionally, krill are economically important, as they are the target of the largest fishery in the Southern Ocean. However, the Antarctic Peninsula (AP), one of the fastest warming regions in the world, is experiencing substantial changes in its pelagic ecosystem. The impact of this warming on krill population dynamics and reproductive success remains unclear. To address this, we analyzed historical krill population data from the AP (January 1999–2011, Palmer Antarctica Long Term Ecological Research) to examine interannual variability in the timing and duration of the spawning season and to identify environmental drivers. We also developed a pregnancy index to quickly assess the sexual development stage of female krill in the field. Our findings showed that both the timing of spawning initiation and the spawning season duration varied annually. Linear mixed-effects models indicated that neither could be directly explained by environmental conditions at the time of sampling. It is likely that oceanographic and climatological conditions in the months preceding the spawning season may significantly influence the reproductive output of mature female krill. These factors will be incorporated into future models, with results shared with the SCAR Krill Expert Group to enhance krill fishery management.