International trade in marine corals depends almost entirely on air freight. A typical shipment from farm or collection site to store takes 24–40 hours, including packaging, flights, customs clearance, and local delivery. Throughout this entire time, corals are sealed inside bags.
Their survival depends less on the flight itself than on how precisely the protocol is followed at every stage — from preparation through to opening the box. Below we break down what correct practice looks like, and why most losses are the direct result of packaging failures.
01
Preparation: Before the Bag Is Sealed
The Darkness Period
Experienced suppliers hold corals in complete darkness for 12–24 hours before packaging. This reduces the activity of symbiotic algae — zooxanthellae — which under light actively photosynthesize and consume oxygen.
In darkness, the coral shifts into a resting state: it consumes less oxygen, produces fewer metabolic byproducts and less mucus. Corals pre-adapted to darkness travel significantly better over long journeys and arrive in a more stable condition.
We hold every coral in darkness before each shipment — this is not an option or an exception; it is a mandatory step in the protocol. A coral packed straight off the shelf, without an adaptation period, is already stressed before the flight even begins.
Water Chemistry
During transport, corals excrete ammonia, carbon dioxide, and organic compounds. Inside the sealed bag, CO₂ accumulates and water pH drops — which temporarily keeps ammonia in its less toxic ammonium form (NH₄⁺).
This is precisely why ammonia neutralisers are added to the shipping water. They reduce the risk of a toxic spike when the bag is opened — especially critical on long-haul routes.
02
Temperature Control
Corals are never shipped at standard reef temperatures. The shipping water must be chilled to 21–23 °C — noticeably below the typical reef range of 25–27 °C.
Lower temperature slows coral metabolism, reduces oxygen consumption, decreases ammonia production, and increases O₂ solubility in water. It also provides a buffer against overheating during delays at cargo terminals.
The Narrow Working Range
Below 19–20 °C, cold stress sets in. Above 24 °C, metabolism accelerates and oxygen is consumed faster. The correct temperature is not simply "cool" — it is a precise range that must be achieved during packaging.
What Is Done Wrong
Some suppliers pack corals in room-temperature water, or water taken directly from the reef tank. Metabolism stays elevated, oxygen depletes faster — and by the time the shipment arrives, there is already a deficit.
03
Packaging: Gas Matters More Than Water
Why Less Water Is Better
Instinct says: more water is better for the coral. This is a mistake many make. In practice, a shipping bag should contain no more than one third water. The remaining two thirds should be gas.
A coral is a living organism. It breathes, absorbs oxygen, and releases CO₂, ammonia, and other metabolic byproducts. The gas volume in the bag serves several critical functions:
- Oxygen reserve for respiration throughout the journey
- Buffer to draw CO₂ and gaseous metabolic waste away from the water
- Dilution of harmful substance concentrations in the aqueous phase
- Shock absorption during vibration and turbulence
When gas volume is insufficient, metabolic byproducts remain in the water, ammonia and CO₂ concentrations build faster, and the coral spends the journey in a toxic environment long before arrival.
In our bags — strictly 1/3 water and 2/3 pure oxygen. Not compressed air, but medical-grade O₂. The difference is fundamental: atmospheric air contains approximately 21% oxygen; a cylinder contains 100%. The reserve for the entire route is secured, even accounting for delays.
- Double or triple sealed bags
- Plastic inserts or cups — the coral does not touch the bag walls
- Dense polystyrene boxes with thermal insulation
Physical Protection
With excessive water volume, corals are knocked against the bag walls during turbulence. Tissue is damaged, creating entry points for bacteria. The correct water volume is also protection against mechanical injury: in a tightly inflated bag with minimal water, the coral is held firmly and does not shift.
A Common Mistake
Bags heavy with water and minimal gas are typical of suppliers who do not understand coral physiology. The coral is submerged in water that rapidly saturates with metabolic waste. By the end of the flight, the animal is already in a toxic environment — even if it looks normal on the outside.
04
Packing Density and Routes
Filling a box to capacity is cheaper for the supplier. But the more corals in a single box, the higher the total biological load: greater combined oxygen consumption, more metabolic waste output, higher bacterial count.
Experienced suppliers deliberately reduce packing density — even when it increases shipping costs. Each coral receives sufficient gas volume. Specimens do not touch each other. The risk of chain bacterial reactions within the box is minimised.
We do not fill boxes to maximum capacity. This is a conscious decision we absorb from our own margin — so that what you ordered actually arrives, rather than whatever survived the flight.
Live marine organism shipments transit through cargo hubs experienced with live cargo — facilities with specialised infrastructure, trained personnel, and environmental controls. Choosing the right route and carrier is also part of the protocol.
05
Hidden Risks: When a Coral Looks Alive but Is Already Dying
The most insidious problem in coral transport is delayed tissue death. A coral arrives, extends its polyps, looks normal. Then 24–48 hours later, tissue begins to recede.
This happens when the coral experienced one or more stressors during transit:
- Oxygen deficit due to insufficient gas volume in the bag
- Toxic ammonia concentration in the water
- Mechanical micro-damage to tissue
- Bacterial contamination from an overcrowded box
All of these risks are a direct consequence of failures at the packaging stage. A correctly packaged coral that travelled 30–40 hours arrives in significantly better condition than an incorrectly packaged one that spent half the time in transit.
Why This Matters When Choosing a Supplier
If a coral died two days after arrival — it is almost always a packaging error, not bad luck. Beautiful photos of healthy corals in a shop do not guarantee that the supplier follows the protocol. Ask directly: exactly how are the corals packaged?
06
After Arrival: The Final Critical Stage
Speed Is the Top Priority
Boxes are opened immediately upon receipt. Every extra hour of waiting increases ammonia concentration in the bag and adds further stress to the coral. By this point the shipping water has already accumulated metabolic waste, and extended drip acclimation in it is dangerous.
Antiseptic Baths and Lighting
Short dips reduce bacterial load and remove parasites before corals enter the main system. After extended periods in darkness, corals are extremely sensitive to light — they receive low light levels (50–100 PAR) with gradual increases over several days.
Quarantine
Professional importers keep corals in a quarantine system for 48–72 hours or more before releasing them for sale. This allows animals to stabilise, reveals hidden issues, and prevents a coral on the edge of failure from reaching the buyer.
Quarantine is a standard part of our intake process. We do not rush to put a coral on sale. The animal must stabilise and confirm it is healthy — only then does it go to the customer.
Why This Matters When Choosing a Supplier
Correct coral delivery is not luck and not "good hands." It is a reproducible protocol that is either followed at every stage — or it is not.
- Darkness period and water preparation before packaging
- Chilling water to the working temperature of 21–23 °C
- Strict ratio: 1/3 water, 2/3 pure oxygen
- Protective inserts, double bags, controlled box density
- Immediate opening and antiseptic baths upon receipt
- Quarantine before release for sale
Each of these steps is performed with every single shipment. Not because it is customary — but because this is precisely why the corals arrive alive.
