Unreliable sources misquotes source 

Your source for the extirpation by whalers of the Atlantic gray whales is suspect. Among the two sources it cites is Bryant's 1995 paper on Atlantic gray whale specimens. Bryant (p. 860, right column) merely speculates that whaling may have been the cause of its disappearance, stating that "This population of gray whales apparently disappeared during periods of active coastal whaling on both sides of the North Atlantic, supporting the possibility [my italics] that whaling activities were responsible for, or at least contributed to, its extinction". However, these whaling activities (as far as we know) primarily targeted right whales, as I stated above. Earlier (p. 860, left column) he asks "Could the eastern North Atlantic gray whale have been extirpated by whaling activities? Unfortunately, early whaling activities off the coast of Europe are poorly documented." This alone is enough to remove your inaccurate assumption, but I'll watch as you scramble for countless secondary sources blindly repeating the same thing again and again. Have fun with that.