That’s pretty much the message of new study in Geophysical Research Letters. Large deposits of methane hydrates, i.e. methane ice, occur naturally in the seafloor sediments of the Arctic continental shelf between 300-600 meters. This is dominate reservoir for methane due to the large area and extremely low temperatures.
The continued and predicted warming of the oceans would cause methane hydrates to melt releasing massive quantities of methane gas, upwards of 16,000 metric tons of methane each year. Fueled by this increase in a food source, microbes that thrive on methane would increase. Their increased respiration would strip the water of oxygen, creating dead zones, and produce carbon dioxide that would acidify waters. These microbial blooms would also remove nutrients from the water depriving other organisms, like phytoplankton thus altering carbon cycling.
So in summary everything is f—-d.
Elliott, S., Reagan, M., Moridis, G., & Smith, P. (2010). Geochemistry of clathrate-derived methane in Arctic ocean waters Geophysical Research Letters, 37 (12) DOI: 10.1029/2010GL043369