Nitrous oxide, more commonly known as “laughing gas,” is a potent greenhouse gas, 300 times more powerful than carbon dioxide. This gas is released into the atmosphere when deep water rises to the surface in a process known as upwelling. One of our studies from that expedition suggested that the sediments below oxygen-depleted waters are a significant source of nitrous oxide (N2O). Although they occur naturally in some areas, dead zones often appear after fertilizer and sewage wash downstream into coastal areas, sparking algal blooms, which then die off and decompose. These harsh environments are uninhabitable for most organisms. This leads to bands of oxygen-depleted water called oxygen minimum zones, or “dead zones.” When organisms die, they sink through the water column, consuming oxygen in the sub-surface ocean as they decompose. Battling rough seas and lack of sleep, we spent the better part of a week working shoulder-to-shoulder in a small stand-up refrigerator, analyzing seafloor sediments to learn more about the effects of low-oxygen conditions on deep-sea environments. Tully in the northeast Pacific Ocean, off the coast of Vancouver Island. In October 2019, I set sail with a team of scientists aboard the Canadian Coast Guard Vessel John P. Restoring coastal ecosystems might help curb climate change. Seabed sediments in Bermuda mangroves consumed nitrous oxide from the seawater.
