loading page

Impact of sea-ice dynamics on the spatial distribution of diatom resting stages in sediments of the Pacific Arctic region
  • +4
  • Yuri Fukai,
  • Kohei Matsuno,
  • Amane Fujiwara,
  • Koji Suzuki,
  • Mindy Richlen,
  • Evangeline Fachon,
  • Don Anderson
Yuri Fukai
Hokkaido University, Hokkaido University

Corresponding Author:[email protected]

Author Profile
Kohei Matsuno
Hokkaido University, Hokkaido University
Author Profile
Amane Fujiwara
Institute of Arctic Climate and Environment Research, Japan Agency for Marine Science and Technology, Japan, Institute of Arctic Climate and Environment Research, Japan Agency for Marine Science and Technology, Japan
Author Profile
Koji Suzuki
Hokkaido University, Hokkaido University
Author Profile
Mindy Richlen
Woods Hole Oceanographic Institution, Woods Hole Oceanographic Institution
Author Profile
Evangeline Fachon
Woods Hole Oceanographic Institution, Woods Hole Oceanographic Institution
Author Profile
Don Anderson
Woods Hole Oceanographic Institution, Woods Hole Oceanographic Institution
Author Profile

Abstract

The Pacific Arctic region is characterized by seasonal sea-ice, the spatial extent and duration of which varies considerably. In this region, diatoms are the dominant phytoplankton group during spring and summer. To facilitate survival during periods that are less favorable for growth, many diatom species produce resting stages that settle to the seafloor and can serve as a potential inoculum for subsequent blooms. Since diatom assemblage composition is closely related to sea-ice dynamics, detailed studies of biophysical interactions are fundamental to understanding the lower trophic levels of ecosystems in the Pacific Arctic. One way to explore this relationship is by comparing the distribution and abundance of diatom resting stages with patterns of sea-ice coverage. In this study, we quantified viable diatom resting stages in sediments collected during summer and autumn 2018 and explored their relationship to sea-ice extent during the previous winter and spring. Diatom assemblages were clearly dependent on the variable timing of the sea-ice retreat and accompanying light conditions. In areas where sea-ice retreated earlier, open-water species such as Chaetoceros spp. and Thalassiosira spp. were abundant. In contrast, proportional abundances of Attheya spp. and pennate diatom species that are commonly observed in sea-ice were higher in areas where diatoms experienced higher light levels and longer day length in/under the sea-ice. This study demonstrates that sea-ice dynamics are an important determinant of diatom species composition and distribution in the Pacific Arctic region.
Jul 2021Published in Journal of Geophysical Research: Oceans volume 126 issue 7. 10.1029/2021JC017223