The phrase "to change the ocean" means to make a big impact or difference in something significant, just like how changing the whole ocean would be a huge transformation. Full definition
Data from multiple sources are combined to produce graphic images of changing ocean conditions. (waterencyclopedia.com)
We work with global ocean circulation models to understand issues like the thermal expansion of ocean waters due to global warming or the effect of changing ocean currents on regional sea levels. (pik-potsdam.de)
This allowed them to construct a history of hurricanes affecting the site, which was compared with reconstructions of changing ocean temperatures over the same period. (wxshift.com)