Microbial plankton in southern Hudson Bay and James Bay in late summer

A first eDNA survey of southern Hudson Bay and James Bay (August 2022–2023) resolved nine plankton communities, with an offshore surface boundary at 55.3°N and ~24.5 salinity.

• Why it matters: Warming and freshening are changing these Arctic waters, but microbial plankton diversity and community structure—especially in James Bay and near the Belcher Islands—were poorly documented.
• What they did: They sequenced 18S rRNA (V9) and 16S rRNA (V4) amplicons from 72 samples at 51 stations, then used hierarchical clustering, distance-based redundancy analysis, and threshold indicator taxa analysis.
• The result: Temperature, salinity, depth, and distance to coast explained 31% of community variation, and the salinity boundary coincided with producer and microbial shifts, implying abrupt ecosystem change as surface waters freshen.

AI summary of the abstract · may contain errors · not medical advice · read the paper.