“A Horrifying New Study Found that the Ocean is on its Way to Suffocating by 2030”. The Smithsonian promoted an article as “Why Our Oceans Are Starting to Suffocate”. The New York Times wrote “World’s Oceans Are Losing Oxygen Rapidly”.
Oxygen is added ti the ocean at the surface, via diffusion from the atmosphere or via photosynthesis. Photosynthesis uses sunlight to break apart water molecules and generate new oxygen while creating organic matter. In the open ocean digestion and decay of sinking organic matter consumes oxygen and releases nutrients. Those nutrients are upwelled from dark subsurface waters back into sunlit waters.
Nutrients in coastal waters is significantly affected by river discharge. Starting around 1950, agriculture rapidly expanded their use of synthesized nitrogen-based fertilizers. This boosted food supplies, but fertilizer runoff decreased coastal oxygen. Sewage and fertilizer run-off combined to stimulate coastal algal blooms that produced excessive organic matter which sank to shallow (< 100 meters) ocean floors.
Its decay consumed bottom water oxygen and created a “dead zone”.
The good news is sewage treatment plants extract solids and recycle them as fertilizer. And farmers are using less fertilizer.
The open ocean away from land, contains natural, permanent “oxygen minimum zones” (OMZ). They are at depths from about 200 to 800 meters.
Open ocean OMZs are ancient. Jellyfish, squid, krill, sea snails, and other invertebrates inhabit them. Sperm whales hunt squid at those depths.
Researchers believe 95% of the global ocean fish mass inhabits OMZ depths. Most of those creatures feed in surface waters, then during the day they return to the OMZs where they digest their food.
Climate alarmists claim global warming is causing OMZ’s to expand and oceans to suffocate. This claim is based on the fact that warmer ocean waters will hold less carbon dioxide.
But the scientific consensus is that the oceans’ surface is supersaturated with oxygen. Because warmer waters stimulate photosynthesis and produce more oxygen. Some researchers found photosynthesis could contribute 2.4 times more new oxygen than is absorbed from the atmosphere. Scientists estimate 50% - 80% of the earth’s oxygen is produced by ocean plankton.
Global warming is not suffocating oceans