Yes, you carefully worded your posts and trod gingerly so as to say nothing overtly wrong, but - reading between the lines - I sensed an unwillingness to take a firm stance on the obvious truth.
Some of the posters in this thread were making ridiculous statements (though, admittedly formulated as questions) about "how can the oceans become oxygen-poor and the fish die if each molecule of H2O itself contains oxygen?" That reflects an ignorance of science tantamount to claiming that the Moon and Sun have the same absolute size. Very disappointing!
For the record, although not an oceanologist, I'm going to go out on a limb here and assert that convection (not conduction) is the dominant form of the conveyance of heat from the surface to the floor of the ocean and that convection (not diffusion) is the dominant form of the conveyance of oxygen.
Regards,
Convection is a stronger factor only when the temperature gradient is greater relative to the oxygen pressure gradient.
But the most important point about this article is that it’s based on politics, not science.
Be very careful with this.