A subsurface eddy associated with a submarine canyon increases availability and delivery of simulated Antarctic krill to penguin foraging regions

• Published in: Marine Ecology Progress Series
• Main Authors: Hudson, K., Oliver, M. J., Kohut, J., Dinniman, M. S., Klinck, J. M., Cimino, M. A., Bernard, K. S., Statscewich, H., Fraser, W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Marine Ecology Progress Series 2022
• Subjects: krill; resource availability; diel vertical migration; retention; biological hotspot; Palmer Deep Canyon; Regional Ocean Modeling System; penguins; antarctica; Antarctic; The Antarctic; Antarctic Peninsula; Austral; Palmer Station; Palmer-Station; Palmer Deep; Antarc*; Antarctic Krill; Antarctica
• Online Access: https://udspace.udel.edu/handle/19716/32282

This article was originally published in Marine Ecology Progress Series. The version of record is available at: https://doi.org/10.3354/meps14211 The distribution of marine zooplankton depends on both ocean currents and swimming behavior. Many zooplankton perform diel vertical migration (DVM) between the surface and subsurface, which can have different current regimes. If concentration mechanisms, such as fronts or eddies, are present in the subsurface, they may impact zooplankton near-surface distributions when they migrate to near-surface waters. A subsurface, retentive eddy within Palmer Deep Canyon (PDC), a submarine canyon along the West Antarctic Peninsula (WAP), retains diurnal vertically migrating zooplankton in previous model simulations. Here, we tested the hypothesis that the presence of the PDC and its associated subsurface eddy increases the availability and delivery of simulated Antarctic krill to nearby penguin foraging regions with model simulations over a single austral summer. We found that the availability and delivery rates of simulated krill to penguin foraging areas adjacent to PDC were greater when the PDC was present compared to when PDC was absent, and when DVM was deepest. These results suggest that the eddy has potential to enhance krill availability to upper trophic level predators and suggests that retention may play a significant role in resource availability for predators in other similar systems along the WAP and in other systems with sustained subsurface eddies. This project was funded through the National Science Foundation, Award Number 1744884 to M.J.O. (University of Delaware) and 1745011 to M.S.D. and J.M.K. (Old Dominion University [ODU]). Computer simulations were run on the Wahab High Performance computing cluster at ODU. We are grateful to the Antarctic Support Contractor and their teams in Denver, CO, aboard the RVIB ‘Laurence M. Gould,’ and at Palmer Station, without whom a project such as this would not be possible. We thank the students and field assistants from ...