The mixture was reportedly leaked while National Grid workers were trying to replace a gas main on Friday, and officials are still working to undo the damage.
Wildlife and local yacht club members alike have been affected by the spill: "The smell was nauseating, I actually had to leave the club it was so bad," said a member of the nearby Midget Squadron Yacht Club.
City workers and Coast Guard officials have been using absorbent pads and oil booms to clean up the mess, but for the time being the city has issued an advisory to avoid fishing or "recreational activity" in the area, which is adjacent to Jamaica Bay.
It's sad, but hey, maybe by now the Gowanus is clean enough for us to fish (and yacht) in instead.
Follow Virginia K. Smith on Twitter @vksmith.