If it enters the fish's environment it can be deadly. It affects many of the fish's organisms and causes it to die. As well it interferes in the photosynthesis process in plants. The salt created by this reaction can kill. It interferes directly with the fish's nervous system.
Acid lakes are deceivingly beautiful.
The are crystal clear and have a luscious carpet of green algae on the bottom. The reason that these lakes are so clear is because many of the decomposers are dead. They cannot break down that material such as leaves and dead animals. These materials eventually sink to the bottom instead of going through the natural process of decomposition. In acid lakes decomposition is very slow.