The Amazing Kordon Breathing Bags For Shipping Fishes, Aquatic Invertebrates, and Aquatic Plants

The following should be of help to you in understanding Kordon's remarkable and unique Breathing Bags for handling and shipping live fishes, aquatic invertebrates, and aquatic plants in bags filled with water.  These Breathing Bags are based on an invention that uses an unique ethylene plastic in the bags to exhale through the wall of the bag the carbon dioxide that builds up in the water, and to inhale oxygen from the air outside into the water in the bag.  This allows safe, long-term handling of aquatic life.  This invention has only been utilized in America by Kordon, and has been commercially provided solely by Kordon for about the past ten years.  It has a loyal following of users who appreciate its special qualities.
 
The Kordon Breathing Bags are manufactured in various sizes, presently from about 4" x 8" to 16" x 30".  They are made of a very special ethylene plastic that for all but the largest bag is 1.5 mil (1.5 thousandths [10-1.5] of an inch [0.0254 x 1.5] in thickness. The largest bag 16" x 30" in size is 3 mil thick, and one half the breathability of the smaller bags due to its plastic's additional thickness. The plastic wall of these bags captures carbon dioxide from the water in the bags as it is formed by the exhalation of fishes and other aquatic life in the water.  The breathing bag forces the carbon dioxide in the water out though the walls of the bag, thereby allowing oxygen to enter the water through the walls of the bag to displace the lack of carbon dioxide.

This is a continuing process, so it provides the ability for the fishes and other aquatic life to be kept in these bags indefinitely -- allowing long shipping or holding times without harm to the bag's occupants.

This can also mean that the fishes can be stored in the Breathing Bags for weeks when they are collected in the tropics from rivers, lakes, or coral reefs  It can mean that the Breathing Bags can be used as containers for fishes or other aquatic life that need to be isolated or quarantined.

The following explanation of Kordon's Breathing Bags is a follow up on an excellent article in TFH magazine on these Breathing Bags, "Believe It or Not...Breathable Bags" by Rusty Wessel (Tropical Fish Hobbyist February issue 2006, pp. 116-119).  Unfortunately, for whatever reason, the Tropical Fish Hobbyist magazine editors would not allow mention of the manufacturer of these bags or allow a follow up clarification of this point.  So even though the article was entirely about Kordon's Breathing Bags, no mention of this was made.   As the supplier of the Kordon Breathing Bags used for shipping fishes and other aquatic life, we would like to add the following facts to what has been presented in Rusty Wessel's article, as well as to add to the product information on this web site that is in the description of Kordon Breathing Bags.

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When we first started shipping with our new Kordon Breathing Bags we were concerned as to whether there was enough oxygen in air cargo to keep everything in the bags alive, and whether there would be shipping boxes that would be incompatible to this technology, cutting off oxygen from getting in the containers.  We were well aware that the higher the air transporters were flying, the less oxygen there is in the air.  And there are cargo holds that are un-pressurized, exposed to the outside lower oxygen level at higher altitudes.

Over the years, without an oxygen problem, we have shipped -- and had shipped around the world to us -- fishes and aquatic invertebrates in millions of our Breathing Bags under many air and surface conditions, and in many kinds of shipping boxes.   We found none incompatible or affecting the survival of the fishes and other aquatic life.  There was plenty of oxygen for fishes and aquatic invertebrates at the highest altitudes that shippers used, whether in air pressured cargo holds or not.

The reason is that at most, the oxygen that fish or aquatic invertebrates are going to have in the water is about 14 ppm (=14 mgl) of oxygen.  Air at sea level is about 21% oxygen.  At higher altitudes the oxygen level goes down, but no where near what is natural for aquatic life.  Whatever the altitude for air transportation, there is plenty of oxygen for aquatic life.
 
All foam and cardboard shipping containers that we and others tried were found to be adequately breathable. 
Even when sealed with tape the shipping containers do not interfere with enough oxygen getting into the Breathing Bags to keep the fishes and other aquatic animals alive and adequately aerated.
 
The Breathing Bags can be sealed all the old ways used for plastic bags, such as with rubber bands or metal clips.  But this way of sealing involves pulling the top of the bag together, causing wrinkles and folds where fishes can be trapped during shipment.   Since no air space is needed in Kordon Breathing Bags for the addition of pure oxygen, the ways for sealing the bags is less limited.  Heat sealers can be used, and this turned out to be by far the fastest and best way to seal Breathing Bags. 

This is done by using an electric bar heat sealer (including impulse sealers and I-bar or L-bar sealers), and even using an electric hair curling iron.  Since there is no oxygen to ignite (oxygen is dissolved in the water), as there would be with regular "barrier" polyethylene bags, this allows fast sealing of the bags without wrinkles in which fishes can become wedged.

Heat sealers make a straight seal and can be done near the top of the bag, eliminating folds and wrinkles.  Used right, an heat sealer can seal at or next to the water line, allowing more of the bag to be used for shipping water, as well allowing the bag to be divided into partitions, making for more versatile bagging.
 
While most shipping is done commercially by fish importers and distributors in larger plastic bags with many fishes or aquatic invertebrates in each bag, this is not the preferable way to ship them.  It is done this way to save labor, so that net fulls of fish can be quickly dumped in a bag, leaving it up to the fish to dodge hitting into each other in the confined space of a shipping bag.  It also saves on bag costs.

During transportation -- being tossed around by airplane or truck movement -- there are continuous opportunities for them to charge into each other, particularly in larger bags where they can speed up their movements, hitting each other and the walls of the bag at higher speed.  This also provides greater risk for the fish to bruise each other, and for infections to be passed on to each other.
 
What is best is to use smaller shipping bags, with as few fish or invertebrates per bag as practical .  The ideal is one per bag.  What is really best is to seal the fishes and aquatic invertebrates in as small individual spaces as practical and to keep the water content to a minimum.  with less ability to dash around in the bag, the less bruising is done to themselves and others.
 
Fishes and aquatic invertebrates can be safely and humanely confined in smaller spaces for shipping than generally realized.   Individual bags can be "pillowed" vertically and horizontally by the bar sealers into a number of chambers.  The fewer fishes there are in a single chamber, the less chance of harmful abrasion. The closer the fishes' gills are to the bag surface the more oxygen they get.

The reason why this procedure is recommended is that the ethylene plastic of the Breathing Bags constantly transfers carbon dioxide from the animals' breathing out through the wall of the bag, allowing oxygen from outside the bag to enter the water through the breathing wall of the bag.   The oxygen is passing first through the water nearest the wall of the bag.  So confining the fishes to near the wall of the bag gets them more oxygen.

As an example of taking this concept to its extreme,  government "Fish & Game Departments" determined that by sealing individual fish (in this example young trout and salmon up to 10-12" in length) in slender tubes by partitioning the Breathing Bags, and transporting them stacked in boxes, the fish had better survival rates than in transporting them free swimming in large water tanks on trucks where the fish slammed into each other and the metal tank walls while the truck bounced around, water sloshing, on back-country roads.
 
Also, we wish to emphasize what Rusty Wessel describes well.  The Breathing Bags should not touch each other during shipment.  It cuts down breathability of the bags by 50%.  They should be separated by newspaper or other paper, or cardboard, or styrofoam sheets or plastic "peanuts," so that the bags are not in contact with each other.  When the bags touch, they breathe through the neighboring bag or bags, and this greatly reduces their breathability.  The government Fish & Game Departments separated their fish in individual tubes by wrapping them in newspaper to keep them breathing without interference from each other.

There is another way that the Breathing Bags can be used.  They can be double sealed, one bag inside the other, with either water-soaked paper in the outer bag or water in both bags, in order to eliminate the loss off fish or aquatic invertebrates if and when they puncture the inner bag.  The oxygen level is lowered in the inner bag by this procedure, but not so drastic that the animals are killed if it is done correctly.   This still requires that the outer Bags be kept from being in direct contact with other outer bags, as described above.

The biggest mistakes we find among users of Breathing Bags are:

(1) Not down-sizing the size of the bags used, forgetting that there is no need for oxygen air space in the bags.
 
(2)  Not understanding that the less water and size of the bags the better for the animals' breathing.  The closer the gills are to the wall of the bag, the more oxygen they get.
 
(3)  Not realizing that having less water can be of help to the fishes, because it slows them down in dashing through the water and slamming into each other and the walls of the bag.
 
(4)  Not realizing that heat sealing the bags is by far the fastest, easiest way to use them.  For commercial shippers it is definitely the most economical way for securing these bags against leakage, and provides cost savings in labor.
 
(5)  Not utilizing the diversity that the Breathng Bags provide in being able to be sealed into multiple chambers, each with its own isolated fish or invertebrate.
 
(6) Not being aware that the bags can be reused a number of times.  "Leakers" can be easily resealed with a heat sealer.  The bags are tougher and longer lasting than most realize.

The Biggest Drawbacks To The Breathing Bags Are:
 
(1) Really spiny and rough-edged fishes and aquatic invertebrates can tear the thin film of the bags.  The user needs to be realistic as to what animals can be transported in these bags.  However, even when fishes poke holes in the bags causing leakage, the ethylene plastic in the bags tries to realign to reseal themselves.  Also see the explanation above about double bagging, water in both bags, or moisture in the outer bag, to reduce punctures and tearing of the inner bag.
 
(2)  The use of Breathing Bags has to overcome decades of the way the original "barrier" polyethylene bags have been used for shipping aquatics.  For many this is the only way that they know about in shipping fishes.  But the polyethylene bags have a severe drawback in having explosive oxygen in the bags.  In fact it is incredible that airlines and the government agencies involved allow the transportation of aquatic animals in oxygenated bags.  The polyethylene bags have severe limits in versatility, taking up more space for the oxygen, and requiring far shorter shipping time than do Breathing Bags.
 
For example, for polyethylene bags requiring the addition of oxygen, all the shipping connections usually have to be within 24 hours to less than 48 hours before all the oxygen in the bags is gone.  Miss a connection and there is a good chance that the fish will die.  Even when users start to try Breathing Bags, they most often start out by using them the same old ways as they used for polyethylene bags, sometimes never revealing the advantages of the Breathing Bags in long-term holding, shipping, and safety.
 
(3) Breathing Bags require a different understanding of shipping aquatic animals.  No oxygen gas or air space is needed in the Breathing Bags, except for a few air breathing fishes that need a tiny air space (but generally no ozygen is needed in that air space).  This means that for all fishes, smaller shipping bags can be used.
Less water should be used because this is better to get oxygen quickly into the fishes and aquatic invertebrates.  The aquatic animals can go for weeks in shipping or storage with limited stress when packed or handled right in Breathing Bags.  Shipping costs can be greatly reduced because there is less weight and volume involved.
 
Breathng Bags are adaptable to use with air-breathing fishes, because the truth is that they all have gills in addition to having convoluted air chambers into which fishes gulp air from the water's surface.  The air chambers are to aid them when there is insufficient oxygen in the water, from which the fish supply oxygen to the gills.
 
For example, when Corydoras air-breathing catfishes are put in the Breathing Bags, without the ability for them to dash to the surface to gulp air, they will often at first look like they are thinking that they are in deep trouble and have to find that open air source -- no matter what.  Then they realize that there is plenty of oxygen in the water and settle down, accepting that they don't really need to find an open air source.  They just need to use their regular gills, not their accessory air-storage organs.

Most air-breathing anabantid gouramies and other air breathers will do the same.  However, some individual gouramies just will not adapt, and need at least a small air space so that they can go through the motion of having gulped air into their gill chamber.  For most air breathers the small air space doesn't need to contain oxygen.  Even an air space with no oxygen will do.
 
(4)  If Breathing Bags are so great, why aren't more commercial shippers using them?  They are safer to use than oxygenated bags.  They take less room, not requiring oxygen, so it costs less in shipping, and this can be significant for long-distance shipping.  They do not require the cost of metal clips or whatever to seal them.   They provide more versatility in sealing and partitioning the bags.
 
The real reasons why more commercial shippers are not using them is that they have not calculated the advantages and cost savings.  And non-breathing polyethylene bags have been around for so long in shipping fishes and aquatic invertebrates, and are so widely available, that the shippers are hesitant to try changes.

Using Kordon Breathing Bags To Ship Aquatic Plants

Aquatic plants need both carbon dioxide and oxygen in their "respiration."  They take in carbon dioxide and exhale oxygen during daylight, and take in oxygen and exhale carbon dioxide at night when there is no light.  Since in shipping boxes there will be no light, this means that the plants are taking in oxygen and exhaling carbon dioxide during shipment. Using Kordon Breathing Bags for aquatic plants requires experimentation with the kinds being shipped.  As a general rule aquatic plants can be successfully shipped in Breathing Bags in which there is ample moisture.

 It is recommended to use either one of the Kordon's NovAquas for a slime coat on the plants to keep them moist and to aid in their respiration.  Even better is to use Kordon's Fish Protector or PolyAqua which provide even thicker slime coatings.  Have ample moisture in the bags so that there is the exchange of carbon dioxide out and oxygen in through the wall of the Breathing Bag.  Since in shipping there will be no light, the Breathing Bags should be fully effective in providing all the oxygen the plants need during shipping.   The advantages for Breathing Bags are that the oxygen they need will be supplied through the walls of the bags.  Not having to fill the bags with water or oxygen will lessen shipping costs.
 
For additional information see the product description for Kordon Breathing Bags, as well as the Kordon Article "Advice For All Shippers Of Fishes And Aquatic Invertebrates now in preparation.

Examples of Shipping Containers: