Both oceans and trees/forests/jungles need help, and us humans need both to work well because together they supply the clean air we breathe. Did you know half of the worlds oxygen comes from the sea. The sea is also a source of water, food and medicine for us.
Our oceans, forests and ice caps. The first two contain most of our natural biodiversity so we need to prevent deforestation and ocean pollution as much as we can. The ice caps are important too because when they melt our sea levels rise. It will get worse the more they melt too because ice reflects sunlight better than the sea. The main thing we can do for this though is to just lower our carbon emissions.