Sundew, on 28 November 2012 - 10:42 PM, said:
I once had a 15 gallon fresh water aquarium I was cycling turn blood red overnight, and just as suddenly the next day it was clear again. I believe the organisms responsible are dinoflagellates, but I did not expect to see them in fresh water or an aquarium. As they are know to give off toxins I did several water changes before adding any fish.
These red tides can be deadly to sea life. Once while in Sarasota, Florida I saw first hand what one can do, thousands of dead fish, crustaceans, mollusks, and other organisms dead and rotting all over the beach. The stench was terrible and the red tide itself makes it hard to breath and burns the eyes if you are near the water.
If that's so, then humans' action is not responsible for these red tides, right?