It is estimated that, as a result of climate change, warming temperatures and an increase in nutrient density, oceans have lost about 2% of dissolved oxygen since the 1950s. Expected to increase by 4% by 2100, this loss rate can be more intense in some locations, such as coastal regions, posing a serious threat to biodiversity. One such area is the Gulf of St. Lawrence in which a certain area is seeing a reduction in the supply of oxygen-rich waters through the Cabot Strait between Nova Scotia and Newfoundland.
However, in a study published in Mitigation and Adaptation Strategies for Global Change, scientists are suggesting using a by-product of green hydrogen production to actually pump oxygen back into the ocean. The team of researchers at Dalhousie University has shown that the proposed green hydrogen industry could, regionally, produce more than enough oxygen to match what is currently being lost from the Gulf of St. Lawrence every year.
Led by Dr. Doug Wallace, an ocean chemist and professor in Dalhousie’s Department of Oceanography, with colleagues from Dalhousie, GEOMAR in Kiel, Germany, and McGill University the team added an inert, non-toxic tracer to deep water in the gulf about 130 kilometers from the location of proposed hydrogen plants, and demonstrated that injected oxygen would travel to threatened regions in 1.5 to 4 years.
More information: Douglas W. R. Wallace et al, Can green hydrogen production be used to mitigate ocean deoxygenation? A scenario from the Gulf of St. Lawrence, Mitigation and Adaptation Strategies for Global Change (2023). DOI: 10.1007/s11027-023-10094-1
