In water however, oxygen levels are much lower, approximately 1%, and fluctuate locally depending on the presence of photosynthetic organisms and relative distance to the surface (if there is more oxygen in the air, it will diffuse across the partial pressure gradient).
Porén, na auga, os niveis de oxíxeno son moito menores, aproximadamente do 1%, e flutúan localmente dependendo da presenza de organismos fotosintéticos e a distancia relativa á superficie (como hai máis oxíxeno no aire, este difunde a favor do gradiente de presión parcial).