how to safety transport koi fish
Excerpt from http://www.mankysanke.co.uk/
Transporting koi safely from one pond to another or to a koi show
It is possible for koi to be transported from the dealer to the home pond, from one pond to another if a koi-keeper should change address, or be transported to and from koi shows without discomfort or risking harm to them provided it is done correctly. There are two main methods; they may be transported individually in plastic bags or in a purpose made transport tank which will usually be designed for transporting several koi at once.
With either method, it is important that the koi should not be stressed either during the netting process, during bagging and transport or when they are released. Stress is a commonly used word in koi-keeping circles but what does it mean?
The purpose and benefits of the stress response
In the very short term, a physical/physiological stress response in animals, including fish, has been an evolutionary advantage. When faced with an environmental condition or a situation that might affect its health or its safety, the automatic response is to release into the bloodstream what are commonly called “fight or flight” hormones. The full physiological effects are too complex to describe in detail here but hormones such as adrenaline and cortisol prepare an animal to fight off the aggressor or to get away from the situation as quickly as possible. Functions such as the heart rate, blood pressure and respiration increase. Blood flow is diverted away from bodily functions that can be dispensed with in the short term in order to allow maximum blood flow to the muscles and parts of the body that are most important to the fight or flight response. After fighting off the aggressor or getting away from the situation as appropriate, the levels of the stress hormones subside. The heart rate and respiration return to normal and such functions as were put on hold for a few minutes can resume.
Since koi were not designed to fight, their preferred response to a fight or flight situation is to swim quickly away to safety. If it is possible for them to do this then the stress response would be a good reaction. The stress hormones which will have allowed the koi to get away from danger can quickly subside with no long term ill effects on it. But what will happen if a koi cannot get away from a situation where it perceives itself as under threat?
The potential harmful effects of continued stress
The stress response evolved to give fish (and other animals) maximum advantage in a fight or flight situation but if a fish cannot escape from the stressful stimulus, the release of stress hormones will not stop after a few minutes, they will continue to be released. The fight or flight response that evolved to provide a short term advantage now begins to work to the detriment of the fish. The heart rate and respiration were not designed to work at elevated levels for longer than a few minutes at a time. Nor were the digestion, immune system and osmoregulatory system intended to be shut down for extended periods. A fish that is stressed for extended periods by its environment or other stressful situations can become physically harmed by processes that originally evolved in order to allow it to swim quickly away from danger. Alternatively, its depressed immune system might allow the koi to fall victim to a disease or pathogen that it might have successfully resisted if its immune system had been working to its full efficiency. This explains why fish sometimes fall prey to diseases such as ichthyophthirius multifiliis (white spot) after being subjected to a stressful journey or situation. This parasite is common in the aquatic environment and is normally successfully resisted by healthy fish but it can take advantage and infect a fish that has an impaired immune system.
The importance of water quality in avoiding stress or harm when moving koi
The fear in a fish of potential danger is not the only stressor (stress stimulus or situation) that can trigger the stress response; this response can also be caused by poor water quality. Just as a potentially dangerous situation would normally cause a koi in a lake to swim rapidly to a safer place, poor water quality would also invoke the same response. A koi in a travel bag or transport tank, in which water quality is poor, will become doubly stressed; firstly by the physical effects of the poor water quality and secondly by the fact that it is unable to swim away to somewhere where the water quality is better.
Preparation when koi are about to be moved is a key factor in ensuring good water quality during transport. Koi are ammonotelic which means that they eat and metabolise protein which results in the waste product, nitrogen, being excreted in the form of ammonia. For this reason, unless the journey is likely to be short, it is a good idea not to feed koi for about five days before they will be transported. This will allow any protein they have eaten to be fully metabolised along with any stored amino acids from that protein. It is the breakdown of protein into amino acids and the further breakdown of those acids that produces ammonia as a waste product so, after this period, although the excretion of ammonia will not cease entirely, it will be very much reduced. Decreasing the amount of ammonia that can build up in a travel bag or transport tank, not only reduces the risk of harm due to ammonia burns, to the gills or fins in particular, but when a high ammonia level reduces water quality in a travel bag or transport tank, a fish will be stressed by that poor water quality.
A second reason to not feed fish for five days before they are moved in order to reduce their ammonia excretions is due to the fact that the ammonia level inside a fish cannot be lower that the ammonia level in its surrounding water. If koi are fed normally before being moved and, as a result, ammonia were allowed to build up in the water in a travel bag or tank, the ammonia level that will build up inside a fish in that water due to it being unable to dump ammonia can cause it to become stressed. In extreme cases, the elevated ammonia level inside the fish may even prove fatal.
A third reason not to feed fish prior to them being moved is because a great deal of oxygen is required in order to digest and metabolise food. Koi that are being regularly fed will take more oxygen from the water than those that haven’t been fed for a few days.
The higher oxygen demand of regularly fed koi in a koi pond is unimportant. As respiration removes oxygen and replaces it with dissolved carbon dioxide, the air stones in the pond will replace that oxygen and help remove the carbon dioxide by a process known as gassing off. When koi are being moved in a bag, the oxygen available to them is obviously limited to whatever is in the bag at the time it is sealed and so, if feeding is suspended prior to them being moved, the oxygen in the water in the bag will not be depleted so quickly. When koi are moved in a transport tank, it is usual for there to be an air pump that can run from the vehicle’s battery and so, as long as this air supply is sufficient, it is arguable that if the koi are only being moved from one pond to another, the higher oxygen demand of fish that have been fed normally will not be important. This is true but since normally fed fish will cause more ammonia pollution in addition to the higher oxygen demand, even koi that are being moved in an aerated transport tank should still not be fed for five days prior to the journey.
It should be noted that where koi are being transported in order to take them to a koi show, not feeding them for the five days prior to the show is also a requirement under the Show Rules and Guidelines of the UK Koi Policy Unit (UKKPU) which were published in November 2010 and which are soon expected to define show protocol for all UK koi shows.
11.4.1 The Koi should not be fed by the Koi Keeper for 5 days prior to travelling to the Koi Show. There is sufficient natural food in the pond to sustain them. This precaution will help to minimise ammonia in the transport bags and significantly reduce the need for water changes due to raised ammonia levels in your Show Vat.
There have always been recommendations regarding feeding koi before koi shows and this rule was written in its present form so as to be compliant with appropriate animal welfare legislation. It has since been adopted in its current wording in the BKKS show rules as published in March 2011.
Oxygen in travel bags
The amount of dissolved oxygen that water can hold is very small when compared with the amount of oxygen in the air above it and since the dissolved oxygen will rapidly start to deplete anyway, it makes sense to have the maximum amount of air in the bag to replace that oxygen as quickly as it is being used even though this will mean having less water. It is necessary to have the gills completely covered when the bag is lying in its normal horizontal transport position but the water need not be any deeper than that. The water in the bag doesn’t need be deep enough to cover the dorsal fin. Fish in a bag need air, not water depth.
Methods for inflating the bag will be described later but if the water just covers the gills when the bag is horizontal and the rest of the bag is filled with air, there will be enough oxygen in that air for one fish for an hour. If the journey and floating time necessary to equalise temperatures is likely to exceed one hour, the space above the water should be filled with oxygen as described in “Inflating the bag” below.
Although there will be more than sufficient dissolved oxygen already in the water and in the air space above for journeys in excess of an hour without the risk of suffocation this should be considered the maximum travelling time for koi without adding oxygen to the bag. If oxygen is added, the higher level of dissolved oxygen that this will produce will go a long way towards ameliorating any harmful effects from the build up of ammonia in the water.
The water in a transport tank or travel bag should, as far as is possible, be prevented from becoming excessively warm during the journey. This will be easier with a tank than it is with a bag because the greater volume of water will change temperature more slowly but both should be shaded from the sun. If the temperature of the water is allowed to rise, the level of dissolved oxygen will fall and it is even possible that, regardless of dissolved oxygen, the water temperature in a travel bag in a car parked in the sun whilst the driver stops for lunch could rise beyond the survivable limit for koi. Journeys should be kept as short as is possible, especially in hot weather.
For journeys significantly longer than an hour in hot weather, there will be an advantage if the transport water is cooled slightly by external ice packs. This will slow the koi’s metabolic rate which will reduce the amount of ammonia it excretes and its oxygen consumption. Decreasing the oxygen consumption in turn will also reduce the build up of carbon dioxide in the water in travel bags. When carbon dioxide is dissolved in water it forms a weak acid, (carbonic acid), which lowers the pH. Koi can acclimatise to a range of pH but they can be stressed if the change happens too quickly. Although it is true that the lower pH would help to protect the koi from the effects of ammonia in the water, [link to explanation to be inserted when available], if the water is cooled slightly, both the build up of ammonia and the rapid decrease in pH will be reduced which is advantageous to the koi. The use of ice packs should not be over zealous. The water shouldn’t be abruptly cooled by more than 2°C or 3°C below that of the water from which the koi is being transferred.
Signs of stress in a fish
Since the evolutionary purpose of the stress response in fish has been to provide it with the best advantage possible to escape from a potentially dangerous situation by physiological changes such as increasing the heart rate, blood pressure and respiration rate, these will be the most noticeable effects that will indicate that a fish is stressed. The normal slow, even and rhythmic gill movements will become more rapid and they will open more widely than usual. The increased blood pressure and blood flow through the capillaries (very fine blood vessels) in the skin will cause a general reddening of the skin and cause the capillaries to become visible as fine thread like red streaks. This is particularly noticeable on white skin. The increased blood pressure in the fine gill capillaries may also cause them to burst resulting in bleeding from the gills.
De-stressing additives to the transport water
Anecdotally, salt, small doses of various fish anaesthetics or proprietary products are not uncommon when transporting fish. Koi dealers and some koi-keepers who are experienced in transporting koi may achieve good results by adding salt or a light anaesthetic or other additive to transport water. If experience shows that the fish are less stressed during transport by these methods, there is no reason why they should be discouraged. But for the lesser experienced hobbyist, since individual methods and conditions of transport are too varied, no recommendation regarding additives to transport water is given here other than to say that if an additive is used, it should be one that is specifically recommended by a manufacturer for this purpose and should be used strictly in accordance with the manufacturers’ instructions.
Netting and bagging
Fish should always be transported in double bags. Strong, clear PVC bags from a koi dealer are ideal, flimsy food bags or similar bags are not. To put one bag inside another, put a small amount of water in what will be the inner bag and drop it into the outer bag, its weight will allow it to fully drop inside. Both bags should be rolled down together by about ¼ their length to form a cuff. This cuff will prevent water getting in between the two bags and also act as a floatation collar allowing the bags to be floated in the water in order to be ready at hand when required.
There are many different methods to net and bag koi. The experienced koi-keeper may have a preferred method which quickly and efficiently transfers the koi into a bag without causing it to be stressed in which case there is no reason to change. For the less experienced, possibly the least stressful way is to use a bowl and a second person to assist.