Or I suppose this could be support for the "Doomsdayers" and the End of Times. Afterall what is the prophetic significance of this and other events effecting the sea?

…And a third of the sea turned to blood. (Revelation 8:8b) The two witnesses) "have the power to turn the waters into blood and to strike the earth with every kind of plague as often as they want." (Revelation 11:6) The second angel poured out his bowl on the sea, and it turned into blood like that of a dead man, and every living thing in the sea died. The third angel poured out his bowl on the rivers and springs of water, and they became blood. " (Revelation 16:3-4)