Biogeochemical feedbacks to ocean acidification in a cohesive photosynthetic sediment.

ABSTRACT: Ecosystem feedbacks in response to ocean acidification can amplify or diminish diel pH oscillations in productive coastal waters. Benthic microalgae generate such oscillations in sediment porewater and here we ask how CO₂ enrichment (acidification) of the overlying seawater alters these in the absence and presence of biogenic calcite. We placed a 1-mm layer of ground oyster shells, mimicking the arrival of dead calcifying biota (+Calcite), or sand (Control) onto intact silt sediment cores, and then gradually increased the pCO₂ in the seawater above half of +Calcite and Control cores from 472 to 1216 μatm (pH 8.0 to 7.6, CO₂:HCO₃^- from 4.8 to 9.6 × 10^-4). Porewater [O₂] and [H⁺] microprofiles measured 16

SUBMITTER: Vopel K 

PROVIDER: S-EPMC8613249 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature