Aquatic life

Chlorine poisoning.

Not a problem I have experienced myself, but almost all public water supplies have chlorine in, and chlorine is toxic to fish.

According to C. van Duijn (Diseases of Fishes), the symptoms of chlorine poisoning are:

The main symptom of chlorine poisoning in fish os destruction of the gills. The gill sheets appear paled and show a whitish discoloration of their tips. At higher concentrations and/or prolonged contact the epithelium of the gills may be completely destroyed and the cartilage laid bare. The skin may get a whitish appearance too. The eyes get sunken in the orbits. At first the fishes show restlessness and irritation, but then their activity slows down, breathing frequency decreases and in the next stage the victims will fall aside and die slowly. Only in the very first stage may the victims recover when transferred to fresh water.

Susceptibility of fishes to chlorine poisoning differs amongst different species.

According to Schäperclaus susceptibility decreases in the following order: Pike (least resistance), Trout, Rudd, Carp, Perch, Tench, Eel (highest resistance).

Chlorinated tap water can be made safe by thorough filtration over activated charcoal.


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Last modified: Fri, 22 Jun 2018 12:41:09 BST
Page first published 2nd March 2003.
Page written and © by Richard Torrens