Oceanographic structure drives the assembly processes of microbial eukaryotic communities

• DOI: 10.1038/ismej.2014.197
• Publication Date: 2014-10-17T13:56:30Z
• Authors: Adam Monier; Jérôme Comte; Marcel Babin; Alexandre Forest; Atsushi Matsuoka; Connie Lovejoy
• Keywords: Downwelling

Abstract Arctic Ocean microbial eukaryote phytoplankton form subsurface chlorophyll maximum (SCM), where much of the annual summer production occurs. This SCM is particularly persistent in Western Ocean, which strongly salinity stratified. The recent loss multiyear sea ice and increased particulate-rich river discharge results a greater volume fresher water that may displace nutrient-rich saltier waters to deeper depths decrease light penetration areas affected by discharge. Here, we surveyed eukaryotic assemblages surface waters, within below SCM. In most samples, detected pronounced usually occurs at interface upper mixed layer Pacific Summer Water (PSW). Poorly developed was seen under two conditions, one above PSW associated with downwelling eddy, second region influenced Mackenzie River plume. Four phylogenetically distinct communities were identified: surface, SCM, weak community just Distance–decay relationships phylogenetic structure suggested ecological processes operating these communities. picophytoplanktons prevalent assembly attributed mass history. contrast, environmental filtering impacted composition communities, heterotrophic Picozoa more numerous. These imply displacement depth terrigenous input act as control on development result lower net primary heterotroph dominated community.