Fisheries: Habitat: Threats

External Disease
Eye Disease
Skeletal Disease
Internal Disease
Causes of Death

Disease in Fish Habitat

All natural ecosystems contain producers, prey, predators and diseases. All of these play a role in the dynamics of the ecosystem, one area affecting the next.

Diseases and disease conditions can be caused by

infectious agents,
natural or manmade changes in the environment, or,
pollutants.

Diseases generally occur as a result of the interactions among a host organism, a causative agent and the environment in which they find themselves. For example, a fish (host) may have a poor immune system resulting from malnutrition caused by environmental conditions such as a severe and prolonged winter. The abundance of a common parasite (causative agent) may be increased in response to environmental conditions (overcrowding of resident fish populations and/or favorable water conditions). With these conditions combined, the chances of a fish succumbing to an infection from the parasite are increased.

As anyone who has owned a fish aquarium knows, fish are capable of contracting various types of diseases. As with humans, diseases can be site specific, affecting certain body parts but not others. When a human contracts a cold virus, the mucous linings of the nose and throat are affected, but the skin is usually unaffected. Fish can have diseases like those that cause fin and tail rot, swim bladder bloating, gill problems and fungal growths on the skin. Some of these diseases are transmittable to humans through consumption of affected fish. Fish that are affected with disease are not recommended for consumption because the disease can affect the quality and taste of the flesh.

Common Diseases of Saskatchewan Fish

While there are many diseases that affect freshwater fish, only a few will be mentioned. Any diseased fish caught in Saskatchewan waters should be handled with care and reported to the district conservation officers, Saskatchewan Environment and Resource Management (SERM) at 1-800-667-7516 immediately. Exact procedures of how to handle and store diseased tissues can be found by contacting SERM.