"Ive shot a 12 guage multiple times into black bird roosts in the dead of night"........"They never became disoriented & crashed into anything."<quoted text> a gas cloud in the water killing the turtles Is plausible. At present with all the earthquakes the planets crust is cracking, These cracks let sequestered gas escape to the surface. It can come up on land and float into the air and be carried on the wind. Or come up in water and follow streams & currents. Im certian The drum fish and bird die offs in Arkansas where caused by a gas. Fracking is done just for that very reason to make cracks in the crust for sequestered gas to follow into the wells. But things commonly go wrong and have bad side effects. Ive shot a 12 guage multiple times into black bird roosts in the dead of night on numerious occasions. And they all but a few that caught a bit if lead flew off into the night. And all we ever exterminated was a couple of dozen birds. It don't kill even a part of 1% of the thousands that try to roost in my cedar glade. All it does is discourage them from establishing a roost. They never became disoriented & crashed into anything.
Do you have night vision?