Silicic acid limitation drives bloom termination and potential carbon sequestration in an Arctic bloom.

ABSTRACT: The spring diatom bloom in the Arctic Ocean accounts for significant annual primary production leading to the most rapid annual drawdown of water-column pCO₂. Late-winter waters in the Atlantic Arctic & Subarctic Provinces (AASP) have lower silicic acid concentrations than nitrate, which suggests diatom blooms may deplete Si before N. Here we test a facet of the hypothesis that silicic acid limitation terminates the spring diatom bloom in the AASP and the sinking of the senescent and dead diatoms helps drive carbon sequestration. During a 6-week study, diatoms bloomed and progressively consumed silicic acid to where it limited their growth. The onset of growth limitation was concurrent with the minimum pCO₂ in the surface waters and increases in both the proportion of

SUBMITTER: Krause JW 

PROVIDER: S-EPMC6544819 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature