What is Stress in Koi and Other Pond Fish
It's hard to define stress but all of know when we feel stressed. Equally we know when we are relaxed and unstressed.
Fish also suffer from stress and stress is so often the diagnosis for koi or goldfish behaving abnormally.
What is Koi Stress?
Stress in Koi and other fish is evidenced by chemical changes created by some interfering mechanism or sudden change such as an attack by a predator or a sudden spike in ammonia levels within the pond. Other physical changes such as increased water temperatures and low oxygen levels in the pond water can bring stress which impacts upon the fish's immune system.
Stress in fish can be created during netting, bagging and transporting fish or by lowering pond levels to clean out the pond for example.
How to Recognize Koi Stress
It's important to observe your koi or goldfish for signs of unusual or erratic behaviour since this is possibly the first sign of stress and is indicative of something having gone wrong in the pond..
Fish gulping air at the surface is a sure sign of low oxygen levels in the pond water causing stress.
Flashing signs are indicative of parasite infestation such as anchor worm causing stress.
If koi maintain a position at a waterfall also may indicate a stressful situation related to low oxygen levels.
Koi that are normally active become lethargic is another sign of stress maybe induced by a predator attack.
Some Pond Fish Stressor Factors
- Adding too much medication to the pond
- Too high a level of nitrates in pond water because there has been no water changes. Nitrate removers like Viresco can be hugely helpful here.
- High levels of nitrite or ammonia in the pond water
- Catching fish in a net
- Being chased at breeding times
- Low dissolved oxygen in pond water
- Excessive plant growth or major algae blooms depleting oxygen content at night time.
- Biofilter not working well enough to cope with overfeeding or low oxygen levels.
- Poor feeding regime with low quality food that reduces ability of immune system over time.
- Predator attack
- Breaking ice in winter
Most of the above are under our own control which means we can help our koi or goldfish lead stress free lives by paying attention to these stress factors.
Related Koi & Gold Fish Articles
Treating and Preventing Goldfish Problems What are the signs
Ulcers on koi and goldfish Medications Dosage Rates Ulcers pond
What if I have overdosed my pond with medications or treatments
What if My fish keep on flicking or scratching themselves