Did all the fish and other aquatic life die in the flood or did Noah have a big tempreture regulated tank?

The Great flood was probably the Mediterranean Sea and it is thought ( I do not know) that the breach was at the Straits of Gibraltar. This allowed the Atlantic to flood in. I do not know if there is a high spot there with a drop on either side but when I was there a couple of years ago I did notice a change in the colour of the sea. To the people living there it would seam that the whole world had been flooded and destroyed. If this is the case (not discussing Noah Ark) Bugs etc. would not die. Presumably some fresh water fishes may have done. Given the scale of the disaster the flooding must have been over a period of time. giving people a chance to forsee what would happen