Which has a greater affect on the production of oxygen, the cutting of trees, or the pollution of the oceans?

Question

Which has a greater affect on the production of oxygen, the cutting of trees, or the pollution of the oceans?

Answer 1

cutting trees is more effect on the production of O2 coz trees use the O2 only n d night and produce it from the beginning of the morning till the sun-set. while these small creatures live n d surface of d oceans( i don know their scientific name) use O2 all d day with a little production of it. so f we continue cutting trees this will decrease the percentage of the O2 more than what the pollution of oceans will do.

Answer 2

I seem to recall hearing in my oceanography class that the ocean produce more oxygen than all the trees in the world.  So if the pollution kills of the algae, which, produces oxygen then the oceans can have a much greater effect over time.