Revelation 16:3 KJV
And the second angel poured out his vial upon the sea; and it became as the blood of a dead man: and every living soul died in the sea.
Revelation 16:3, King James Version
In context
2 And the first went, and poured out his vial upon the earth; and there fell a noisome and grievous sore upon the men which had the mark of the beast, and upon them which worshipped his image.
3 And the second angel poured out his vial upon the sea; and it became as the blood of a dead man: and every living soul died in the sea.
4 And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood.