Autonomous sensors powered by a benthic microbial fuel cell provide long-term monitoring of the northeast pacific oxygen minimum zone

An autonomous sensor platform powered by a benthic microbial fuel cell (BMFC) has been developed and deployed to supply hourly dissolved oxygen (O
2
), temperature and conductivity measurements from a remote location in the core of the oxygen minimum zone of the northeast Pacific. The platform uses a compact acoustic modem to both store and transmit sensor and energy harvesting measurements. Initial results from the first 150 days of operation are reported. The platform's sensor measurements compare well to data from a nearby cabled benthic experiment package maintained as a component of the “Endurance Array” of the U.S. Ocean Observatories Initiative. The promising performance of our platform makes it a candidate for an expanded O2 observing system needed to provide global O2 inventories through time. Only through analyses of wide-spread long-term measurements can ocean scientists corroborate model predictions that key sectors of the ocean are losing oxygen due to climate change.