Variable carbon isotope fractionation of photosynthetic communities over depth in an open-ocean euphotic zone.

ABSTRACT: Marine particulate organic carbon (POC) contributes to carbon export, food webs, and sediments, but uncertainties remain in its origins. Globally, variations in stable carbon isotope ratios (δ¹³C values) of POC between the upper and lower euphotic zones (LEZ) indicate either varying aspects of photosynthetic communities or degradative alteration of POC. During summertime in the subtropical north Atlantic Ocean, we find that δ¹³C values of the photosynthetic product phytol decreased by 6.3‰ and photosynthetic carbon isotope fractionation (ε_p) increased by 5.6‰ between the surface and the LEZ-variation as large as that found in the geologic record during major carbon cycle perturbations, but here reflecting vertical variation in δ¹³C values of phot

SUBMITTER: Henderson LC 

PROVIDER: S-EPMC10927520 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature