Dolphins are butchered in Japan and in Denmark, probably other places as well. They are part of the less than 10% left of edible fish and sea mammals left. Much of the phytoplankton food base is also gone from the ozone layer thinning and acidification with warming. 6 huge gyres of trash, mainly slow breakdown plastics are in the oceans along with mercury fallout from coal fired power plants. It is estimated that before 2050, the entire world's oceanic fisheries will be gone, along with a big chunk of the food humanity came to rely on. The sick oceans, then as they warm deeper, explosive and massive methane releases to shoot up the warming further. Then, maybe in 2 million years, the oceans will be back similar to what they were, but with new species. One species out of the many that will die, when efforts should be made to mitigate everything affecting the entire system, and especially root causes.
