Perhaps, but not necessarily. There are real concerns that with a combination of temperature rises, ocean acidification, and trophic cascades caused by overfish

Perhaps, but not necessarily. There are real concerns that with a combination of temperature rises, ocean acidification, and trophic cascades caused by overfishing, the oceans will entirely die in the medium term. They are certainly in the process of dying (like nearly all ecosystems under the assault of 'economic growth').