Resource icon

Fish stress

Fish stess what are the causes to tell you the truth this can be a somewhat complex thing to get to the bottom of.

Too much stess in our pond enviroment is bad for our fish and can cause all sorts of problems that need read about then taken to heart.

Stress in all its forms can seriously upset our fishes immune system which can lead to all sorts of fish health problems, even death.

In our pond we have a 29 year old koi, he has had his scrapes the most recent was a lightening strike on the pond however for most of his long life I've always tried to ensure that the enviroment he and our other koi live in is at its best.

So what can stress out our fish well I put my thinking cap on and I will try to list everything I could come up with that can cause it ......

1) First that comes to my mind is overcrowding this has to be the main cause of stress in the pond so when you buy your fish use sensible stocking and it will be avoided.

2) Net Stress: A bad netting technique can cause your fish stress and physical damage learn good netting procedures.

3) Ph and sudden changes to it: Those of us that know to take Ph readings know to take it at two differing times during the day. This is because to some degree or other it will fluctuate and as such you need a stable Ph use a buffer to your Kh. We use Lythaqua it helps keep the Ph of our ponds stable, a Ph that is either too high or too low can be a major cause of stress, so remember we need to keep it as stable as possible.

4) Water temperature: The deeper your pond the better - many koi keepers have ponds between 4.5ft to 5ft in depth, shallower ponds heat up much more quickly than a deeper pond does causing stress, as does winter cold which can cause your fish stress. To this end we have fully insulated everything including the pipe work and cover the pond with policarbonate sheeting to slow any heat loss to a minimum if it goes bellow 7c we have a small oil heater radiator in our filter housing to push it back up which comes on automatically.

5) When we purchase our fish a proper period of acclimatization should always be observed, we normally float our koi in the bag for up to 40 minutes checking the bag with a hand held infrared thermometer to make doubley sure that the temperature of the bag and that of the pond are one and the same before releasing our fish into the pond. This applies to all fish remember they are a coldblooded creature. Water quality is a must maintenance and routine water changes.

6) Ammonia and nitrite are present in our ponds water to some degree, however we need to keep these levels to the barest minimum. Filtration is the key to breaking down Ammonia, and Nitrite should be removed or taken up by plants. This is where regular water changes are a must.

7) Stress through illness or infection should be avoided. Learn to read your fish - check them over when you feed them for any type of damage or infection from fish pathogens / parasites because this can increase the stress levels of our fish ten fold thus limiting their ability fight it off.

8) Diet can be another cause of stress make sure you work out a regular dietry plan. Make sure the right food is fed at the right time of year, i.e Wheatgerm and garlic late summer and late spring, then a higher protiened diet in the summer months thus building up bady mass ready for the no feed period bellow 10c.
Only feed as much as they can eat in 5 minutes spread the food thoughout the day in sall quantities. Alternate foods can be used - see article on Alternate foods but only as a treat to ensure they get the nutients they need from pelleted foods.

9) Breeding: This can be a highly stressful time for the females, so ensure you have the right ratio of males to females. It can be an extermely stressful time for the females if you get it wrong and even with the right ratio serious damage can occur, especially in koi. Serious amounts of ammonia can be released, so make sure this is removed ASAP. Furthermore eggs can clog filters affecting filtration make sure they are cleared. We are lucky we have a shoreham QT facility with which we can breed specific koi in thus lessening the hamful affects on the ponds filters.

10) Lack of sufficient oxygen in our ponds water: Fish rely on dissolved oxygen in the water for their respiration, do not overstock your pond as this is one of the most common cause of low dissolved oxygen.

11) Low aeration: Make sure you maintain good aeration on your pond via your air pump, relace your airpipes once every year, plus clean airpump out from time to time, remove and replace its diaphram to ensure a future good airflow.

12) Fish can and do get highly stressed due to bad stimuli from outside of the pond, such as birds of pray and other raptors. Provide cover or break up the suface of the water to break up their outline, if your fish seem nervous or very skittish count your fish to see if the pond has had a preditor visit, tell-tale damage such as a fish with a hole may indicate a Heron is visiting your pond. Put out decoys this may well help stop your fish from becoming food.

13) Toxins: This can come in the form of them being washed into your pond by run off accidental spillage, pestiside spray and many other vectors often washed in by heavy rains. Toxins may do more than stress your fish the can even kill them. Chlorine and chloramines are common additives to tap water and if not removed can cause severe stress or even death. Use dechlorination / chloromines liquid or like ourseves by a water filtration unit to run your tap water through then into the pond. But if toxins are suspected immediate water changes are hightly recommended.

14) Always remember in the case of some species like Orfe remove them at the start of any pond treatment.

15) Goldfish if treated with superverm will die.

17) Malchite green and Formalin is a treatment we often use but how many of us know with a Ph level of 8.5 the water may well turn the water toxic if it has salt in it?

18) it has been proven by the research of Professor Victoria Braithwaite and her team of researchers that fish can feel pain and have some cognative abilities, as such it is only logical that having the ability to feel it that it is going to affect a fishes welfare and cause them great stress which as we already know can affect our fishes immune system leaving them open and under threat

I hope this helps should your fish be suffering with stress what ever the species