Skimming the conclusion of the paper it seems that, unless there are overlooked measurement errors the effect is robust. The immediate question this suggests to me is this: are there any naturally occurring multi-year (or multi-decade) oxygen concentration cycles in the ocean analogous to already-known salinity cycles?
This was where I immediately started thinking. Is this something that cyclical? The article is long on effect and very short on causes.
"Reducing greenhouse gas emissions, nutrient runoff and organic carbon inputs (for example, raw sewage loading) would slow or potentially reverse deoxygenation," they write.
And what exactly is "raw sewage loading" they talk about as a way to reverse this? I did some quick googling and couldn't find anything about what exactly it is.
Don't go swimming too soon after it rains if you want to be safe from E. coli. Overdevelopment, underfunded utilities, and factory farms put runoff at a level that's barely tolerable when it's dry, and when there's excess surface water, they overflow in unsanitary ways that result in nutrient blooms and oxygen depletion.
It's literally what it sounds like: dumping untreated sewage into waterways and oceans.
A big problem in all of these is adding nitrogen and phosphorus to the water, which facilitates algae growth, which consumes a lot of the available oxygen:
Urine and feces are great sources of nutrients - good if you extract them, sterilize, and use responsibly on land, not good if you dump directly into water.
Data point: IIRC the Great Lakes were getting choked on algae until they banned phosphates in detergents. And of course there is always fertilizer runoff.
there is a natural phenomenon known as wetland. these things reclaim, and redistributex raw materials that are like rocket fuel for microbes.
these wetlands are inconvienient for [growth] as they take up a lot of area, andget in the way of housing developments, parking lots, and sewage treatment plants.
the solution is attempted dilution,thus:
>>It's literally what it sounds like: dumping untreated sewage into waterways and oceans.<<
This article seems to be based on quite a technical paper but my reading is hot water holds less oxygen so global warming is a factor. Also excess organic matter from farming is causing oxygen loss as it decomposes to CO2 and a few other processes.
I read that as a clarification of organic carbon inputs that could be reduced. I don't know the specific phrase "raw sewage loading," but in context I assume its something to do with sewage waste being released into rivers and oceans.
