Sorry up front, I'm not trying to be an jerk, but...
Wouldn't the fishing industry around the town be decimated if once/month this boat comes in and kills all the fish life?
And after month 1, where would the new fish come from? I could *maybe* see them coming from further upshore or something, but after month 2/3, I can't imagine anything living in the waters anywhere near this coastal town.
Ayrn