Revelation 16:3
And the second angel poured out his vial upon the sea; and it became blood like that of a dead man: and every living soul in the sea died.
Revelation 8:8-9
And the second angel sounded, and I saw as it were a great mountain on fire cast into the sea, and a third part of the sea became blood.
Revelation 11:6
These have power to shut the heavens, so that no rain may fall in the days of their prophecy: and they have power over the waters to turn them into blood, and to smite the earth with every plague as often as they will.
Revelation 10:2
And he had in his hand a little book open: and he set his right foot upon the sea, and his left upon the earth.
Revelation 13:1
And I stood upon the sand of the sea, and I saw a beast rising up out of the sea, which had seven heads and ten horns; and upon his horns ten crowns, and upon his heads the names of blasphemy.