Cross reference
Exodus 7:21
21 And the fish that was in the river died; and the river stank, and the Egyptians could not drink of the water of the river; and there was blood throughout all the land of Egypt.
Exodus 7:18
18 And the fish that is in the river shall die, and the river shall stink; and the Egyptians shall loathe to drink of the water of the river.
Revelation 8:9
9 And the third part of the creatures which were in the sea, and had life, died; and the third part of the ships were destroyed.