Variability in spring phytoplankton blooms associated with ice retreat timing in the Pacific Arctic from 2003-2019

PLoS One. 2021 Dec 16;16(12):e0261418. doi: 10.1371/journal.pone.0261418. eCollection 2021.

Abstract

The Arctic is experiencing rapid changes in sea-ice seasonality and extent, with significant consequences for primary production. With the importance of accurate monitoring of spring phytoplankton dynamics in a changing Arctic, this study further examines the previously established critical relationship between spring phytoplankton bloom types and timing of the sea-ice retreat for broader temporal and spatial coverages, with a particular focus on the Pacific Arctic for 2003-2019. To this end, time-series of satellite-retrieved phytoplankton biomass were modeled using a parametric Gaussian function, as an effective approach to capture the development and decay of phytoplankton blooms. Our sensitivity analysis demonstrated accurate estimates of timing and presence/absence of peaks in phytoplankton biomass even with some missing values, suggesting the parametric Gaussian function is a powerful tool for capturing the development and decay of phytoplankton blooms. Based on the timing and presence/absence of a peak in phytoplankton biomass and following the classification developed by the previous exploratory work, spring bloom types are classified into three groups (under-ice blooms, probable under-ice blooms, and marginal ice zone blooms). Our results showed that the proportion of under-ice blooms was higher in the Chukchi Sea than in the Bering Sea. The probable under-ice blooms registered as the dominant bloom types in a wide area of the Pacific Arctic, whereas the marginal ice zone bloom was a relatively minor bloom type across the Pacific Arctic. Associated with a shift of sea-ice retreat timing toward earlier dates, we confirmed previous findings from the Chukchi Sea of recent shifts in phytoplankton bloom types from under-ice blooms to marginal ice zone blooms and demonstrated that this pattern holds for the broader Pacific Arctic sector for the time period 2003-2019. Overall, the present study provided additional evidence of the changing sea-ice retreat timing that can drive variations in phytoplankton bloom dynamics, which contributes to addressing the detection and consistent monitoring of the biophysical responses to the changing environments in the Pacific Arctic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arctic Regions
  • Biomass
  • Chlorophyll A / analysis
  • Climate
  • Ecosystem
  • Eutrophication*
  • Ice Cover*
  • Pacific Ocean
  • Phytoplankton / growth & development*
  • Satellite Imagery
  • Seasons
  • Temperature

Substances

  • Chlorophyll A

Grants and funding

HW received funding supports from the Grant-in-Aids for JSPS Overseas Research Fellowships and Early-Career Scientists 21K14894, and the Arctic Challenges for Sustainability (ArCS) Program for Overseas Visit by Young Researchers. TH received funding support from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT) through the Arctic Challenge for Sustainability II (ArCS II). YF received funding support from the Grant-in-Aid for Scientific Research (B) 19H01961. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.