Open AccessEphemeral aggregate layers in the water column leave lasting footprints in the carbon cycle
Author(s) -
Prairie Jennifer C.,
Ziervogel Kai,
Camassa Roberto,
McLaughlin Richard M.,
White Brian L.,
Johnson Zackary I.,
Arnosti Carol
Publication year - 2017
Publication title -
limnology and oceanography letters
Language(s) - English
Resource type - Journals
ISSN - 2378-2242
DOI - 10.1002/lol2.10053
Subject(s) - water column , marine snow , biogeochemical cycle , environmental science , carbon fibers , carbon cycle , aggregate (composite) , total organic carbon , dissolved organic carbon , organic matter , carbon flux , oceanography , environmental chemistry , ecology , chemistry , ecosystem , geology , biology , materials science , composite number , composite material
Marine aggregates play a critical role in the biological pump, both as a dominant component of carbon flux and as hotspots for organic matter remineralization by microbial communities. In this study, we used laboratory experiments to investigate how aggregate thin layers, such as those commonly found in the coastal ocean, affect the distribution of bacteria and their activity. Diatom aggregates were added to a stratified water column, forming layers within which both microbial concentration and extracellular enzyme activity were substantially increased relative to background levels. Importantly, this enhancement of bacterial concentration and activity persisted long after the marine snow aggregates settled through the tank—that is, 10 times longer than the duration of the aggregate layer at the density interface. Thus, these small‐scale microbial interactions within aggregate layers leave behind considerable “carbon processing footprints” in the water column that may affect biogeochemical cycles at much larger temporal and spatial scales.