How do fishes die naturally?
The most common cause of natural fish kills is lack of oxygen in surface water. Lack of oxygen can asphyxiate most susceptible fish species within a few hours. Depletion of oxygen in water can result from natural processes and storm events are very often involved.
What do fish do when dying?
Most fish sink to the bottom of their habitats when they die but they become more buoyant as the process of decomposition takes over. Most fish are slightly denser than water, so sink immediately after death.
How do fish die in a fish tank?
Improper tank is the most common reason for fish death. Most of the time, when the fish tank is not prepared properly, all or a lot of the fish die. It majorly happened with the beginners. In really bad tank conditions, the fish may die overnight, but generally, it happens over a few days or a week.