Different ocean depths have different oxygen levels. Near the surface the ocean has a similar oxygen level to the air.
Organic matter sinks down, and is eaten by bacteria and such as it goes. Oxygen levels can decrease with depth because it is used up by those bacteria in the deeper water. Below a certain point the organic matter decreases to basically nothing because it has been eaten and/or biodegraded, so there is less life the deeper you go because there’s nothing for it to eat. Very deep ocean can have a higher oxygen level than above because 1. It’s colder and colder water holds more oxygen 2. There are less organisms using up the oxygen.
Basically that octopus in the shallow water is getting plenty of oxygen since surface water has a lot.
Latest Answers