An increase in Earth's temperature caused many changes in the sea, such as species extinction and species invasion.
An example of species extinction is Kinnert Bleak (fish):
The increase in temperature causes a drop in Kinnert level, and reduces the breeding grounds of Kinnert Bleak. As a result, the number of fish in the Lake is decreased and in the end, this will lead to its extinction.
An example of species invasion is Cyanobacteria:
Cyanobacteria is able to perform Photosynthesis in high temperatures. Thus, unlike other species, it can adapt to the water's high temperature, and this enables it to become an invasive species.
The graph below shows the change in global temperature and carbon dioxide concentration over a 120 year period