Spatially Variable Bioturbation and Physical Mixing Drive the Sedimentary Biogeochemical Seascape in the Louisiana Continental Shelf Hypoxic Zone.

ABSTRACT: Seasonal hypoxia on the Louisiana continental shelf (LCS) has grown to over 22,000 km² with limited information available on how low oxygen effects the benthos. Benthic macrofaunal colonization and sediment biogeochemical parameters were characterized at twelve stations in waters 10 - 50 m deep along four transects spanning 320 km across the LCS hypoxic zone in the early fall of 2010 when bottom waters typically return to oxic conditions. Chemical data and sediment profile imaging (SPI) support three primary mechanistic pathways of organic matter degradation on the LCS: (i) metal oxide cycling in depositional muds, (ii) infauna-driven bioturbation delivering oxygen below the sediment-water interface, and (iii) sulfate reduction in sediments where iron oxide availability is limit

SUBMITTER: Devereux R 

PROVIDER: S-EPMC6541407 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature