Ocean ‘Dead Zones’ With Almost No Oxygen to Sustain Life May Be Expanding Far Quicker Than Thought – Scitech Daily

Dead zones within the world’s oceans — where there is almost no oxygen to sustain life — could be expanding far quicker than currently thought, a new study suggests.

The regions are created when large amounts of organic material produced by algae sinks towards the seafloor, using up the oxygen present in the deep water.

….. a study published in Global Biogeochemical Cycles suggests that dark carbon fixation — caused by the presence of anaerobic bacteria in the deeper water column — needs to be incorporated into these models….

…..using a distinct biomarker produced by anaerobic bacteria, they suggest that around one fifth of the organic matter on the seafloor could in fact stem from bacteria living in or around these dead zones.