IMPACT OF WARM-CORE EDDIES AND DIEL VERTICAL MIGRATION ON ZOOPLANKTON DISTRIBUTIONS

The ocean’s mesopelagic, or twilight, zone is critically important to biogeochemical processes influencing Earth’s climate. Through their feeding and migratory behaviors, mesopelagic zooplankton play key roles in the biological carbon pump, which transfers carbon from the surface ocean to the deep sea where it is sequestered. However, more information is needed on zooplankton species diversity and factors affecting their distributions. The goals of this study were to determine the impact of a warm-core eddy on zooplankton diversity and vertical distributions in the Northwest Atlantic Ocean. The study takes advantage of depth-stratified MOCNESS zooplankton tows conducted in neighboring Slope Water stations during a 2019 oceanographic cruise on the NOAA Ship Henry B. Bigelow, with different water mass characteristics reflecting the influence of a warm-core eddy in one of the stations. Two nighttime and two daytime tows were conducted in the eddy-influenced sampling station and two nighttime and one daytime tow were conducted in a nearby area outside the influence of the eddy. DNA metabarcoding of the species-specific COI barcode marker was conducted on the net contents. We found that that the eddy-influenced station had greater species richness, reflecting the mixing of animal communities of different origins. We additionally determined the daytime and nighttime depth distributions of the different species and identified typical as well as many reverse vertical migrators. We discuss the implications of our findings for understanding mesopelagic zooplankton functional roles.

Presentation Preference: Oral

Primary Presenter: Annette Govindarajan, Woods Hole Oceanographic Institution (afrese@whoi.edu)

Authors:

Annette Govindarajan, Woods Hole Oceanographic Institution  (afrese@whoi.edu)

Joel Llopiz, Woods Hole Oceanographic Institution  (jllopiz@whoi.edu)

Michael Jech, NOAA Northeast Fisheries Science Center  (michael.jech@noaa.gov)

Andone Lavery, Woods Hole Oceanographic Institution  (alavery@whoi.edu)

Peter Wiebe, Woods Hole Oceanographic Institution  (pwiebe@whoi.edu)

Nina Yang, Woods Hole Oceanographic Institution  (nina.yang@whoi.edu)

Weifeng Zhang, Woods Hole Oceanographic Institution  (wzhang@whoi.edu)