John the Apostle
Revelation 16:3ESV·traditional attribution

The second angel poured out his bowl into the sea, and it became like the blood of a corpse, and every living thing died that was in the sea.

Matthew Henry Presbyterian @wholebiblehenry

We had in the foregoing chapter the great and solemn preparation that was made for the pouring out of the vials; now we have the performance of that work. Here observe, I. That, though every thing was made ready before, yet nothing was to be put in execution without an immediate positive order from God; and this he gave out of the temple, answering the...

Commenting on Revelation 16:1-7

John Gill Reformed Baptist @doctorgill

And the second angel poured out his vial upon the sea,.... Not literally; and so does not design the stagnation of it, which it is thought will be before the general conflagration; see Amo 7:4 nor is it to be understood of the sea of this world, and the men of it, who are like a troubled sea; but rather of Popish doctrines and councils...

Albert Barnes Presbyterian @notesbybarnes

Verse 3. And the second angel poured out his vial upon the sea. So the second trumpet, (,) "And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood." For the meaning of this as a symbol, . And it became as the blood of a dead man.