Hydrothermal vents supporting persistent plumes and microbial chemoautotrophy at Gakkel Ridge (Arctic Ocean)

Area of Science:

• Marine biology
• Geochemistry
• Microbial ecology

Background:

• Hydrothermal vents release energy-rich fluids, supporting unique microbial ecosystems in the deep ocean.
• The Gakkel Ridge in the Central Arctic Ocean hosts recently discovered volcanic seamounts with hydrothermal activity.

Purpose of the Study:

• To compare the ecological and biogeochemical impacts of hydrothermal venting at the Polaris and Aurora seamounts.
• To identify the primary energy sources fueling microbial life in Arctic hydrothermal plumes.

Main Methods:

• Analysis of microbial carbon fixation rates in hydrothermal plumes.
• Quantification of microbial community composition using relative abundance.
• Transcriptomic analysis to identify active metabolic pathways.

Main Results:

• Microbial carbon fixation rates were significantly elevated in both plumes compared to background Arctic deep water.
• Hydrogen and sulfide were identified as dominant energy sources, supporting high chemoautotrophic activity.
• Distinct microbial communities and metabolic pathways were observed at Polaris (sulfur oxidation) and Aurora (hydrogen oxidation).

Conclusions:

• Arctic hydrothermal vent plumes significantly enhance microbial productivity.
• Hydrogen and sulfide are key drivers of microbial ecosystems in these environments.
• Site-specific geochemical conditions influence microbial community structure and function.