Revelation 16:3-6

The second angel poured out his bowl into the sea, and it turned into blood like that of a corpse [foul and disgusting]; and every living thing in the sea died. Then the third angel poured out his bowl into the rivers and the springs of water; and they turned into blood. [Ex 7:17-21] And I heard the angel of the waters saying, “Righteous and just are You, Who are and Who were, O Holy One, because You judged these things; for they have poured out the blood of the saints (God’s people) and the prophets, and You [in turn] have given them blood to drink. They deserve Your judgment.” [Ps 79:3]