This looks exactly like the strange orange ring that appeared in my koi pond in Florida. Shortly after the oil spill, I added water from my hose. The water became impossible to filter. None of the debris in the pond would stay in the filter. The debris was suspended in some strange gel-like substance. An orange ring- exactly the same color as that alligator appeared at the top of the water on the black pond liner. It's like cement and can not be scraped off.I had a 3 month period of trying to figure out how to trap the stuff and remove it + spending lots of money to fix the ph.Fish were dying. If this is from that oil / corexit, it's in our aquifer and water that we shower and wash our clothes in. Scary. They need to trap that gator and test it!