Key Takeaways
- Frozen seafood stored at -20°C (-4°F) can stay in top condition for up to 8 months, while storage at -15°C (5°F) limits shelf life to roughly one month.
- The FDA’s two-hour rule applies during transit: seafood left above 4°C (40°F) for over two hours enters the bacterial danger zone.
- Leak-proof bags, insulated containers, proper refrigerants, and correct labelling are the core elements of safe seafood shipping.
- DNV-certified offshore reefer containers with microprocessor temperature controls, like those offered by MGS, help maintain an unbroken cold chain across international routes.
How to Ship Seafood: What You Need to Know Before Anything Leaves the Dock
Knowing how to ship seafood, whether fresh or frozen, starts with one non-negotiable: maintaining an unbroken cold chain from origin to destination.
A cold chain is the continuous series of temperature-controlled steps (storage, packing, transit, and delivery) that keep perishable goods at safe temperatures throughout the shipping process. Break any link, and you risk spoilage, bacterial contamination, and significant financial loss.
MGS IceStorm, a DNV-certified offshore reefer container provider with over 13 years of experience in perishable shipping logistics, has put together this guide covering everything from packing methods and documentation to choosing the right refrigerated containers for your shipment.
Seafood including fin and groundfish (haddock, plaice, cod, tuna), crustacean shellfish (crab, lobster, shrimp), gastropods (periwinkles, sea-snails) and bivalve molluscan shellfish (oysters, cockles, clams, mussels)– is highly perishable by nature. Like any perishable item, seafood can spoil or bruise if not shipped carefully.
As such, it’s important to have a strong understanding of the requirements and unique preparation process entailed in safely delivering seafood to its destination.
Photo by Mike Bergmann on Unsplash
Key challenges of shipping seafood
Understanding how to transport seafood properly means first understanding what can go wrong. The main challenges involved in shipping seafood are:
- Fermentation during rainy or hot seasons.
- Bacterial growth and low temperatures
- Lack of record keeping and lapses in resource management
- Deficient cold storage and unhygienic environments
- Lack of real-time traceability
- Excessive loss of moisture that can cause freezer burn — a condition where frozen food develops dry, discoloured patches due to air exposure, degrading texture and quality.
How to pack seafood for shipping?
Proper packing is the foundation of how to ship frozen seafood safely. A well-packed shipment controls temperature, prevents leakage, and protects product integrity from warehouse to final delivery. The following are the recommended steps to pack seafood before shipping:
- Place your frozen seafood in protective plastic bags that are at least 4mm thick and puncture-resistant.
- Use zip-ties to secure the bag to prevent any leakage and spillage.
- Twist, fold, and remove excess air, then tie the bag tightly.
- Repeat the previous step and add frozen gel packs to the next plastic bag at the bottom. Then place the seafood package on an absorbent mat inside the box and bag, twist, fold, and tie again.
- Prepare an insulated container and make space for dry ice. Keep seafood packages in the container with dry ice, and fill the space with loose-fill packing peanuts or mic-pack polyform.
- Close the insulated container lid, but not fully because dry ice releases CO₂ gas and needs ventilation.
- Place the insulated container box into an outer corrugated box and pack the box with the H-taping method, applying tape to all flaps and seams.
Materials needed to package seafood
To package seafood, these materials are typically used:
- Dry ice/ gel pack/wet ice
- Dry Ice labels
- Insulated container lid
- Outer corrugated box
- Insulated container
- 2-mil plastic liner
- Absorbent mat/towel
- Zip-tie or another tie
- 3-4 plastic bags at least 4mm thick
Seafood shipping process
Whether you’re figuring out how to ship fresh seafood across borders or how to ship frozen seafood to offshore platforms, the logistics process follows a similar sequence:
Step 1:Ask the shipper or carrier for a quote before commencing the shipping of fresh seafood.
Step 2: Hire a competent and reputable freight forwarder to manage the complete freight process.
Step 3:Issue a purchase order so the freight forwarders can arrange the transportation of goods.
Step 4: Get a letter of credit from your bank so that the supplier can issue the order confirmation and commercial invoice for custom clearance.
Step 5:Ensure your shipper prepares the following documents in accordance with the regulatory statutes of the territory:
- Shipper’s letter of instruction
- Certificate of Origin
- Dangerous goods
- Export declaration
- A permit to export/import prohibited goods
Step 6: To avoid any possible delays, book freight early so that goods are easily processed through customs clearance and export declaration.
Step 7: Confirm that the cold chain will remain unbroken during transit. This means verifying that reefer containers or refrigerated transport are operational and set to the correct temperature before loading.
Step 8:After passing the custom process, your goods should be delivered to the buyer or consignee.
Tips for safely shipping seafood.
1. Pay attention to temperature and heat.
The storage life span of frozen seafood depends on the temperature of the environment in which it is stored. For instance, when fish is frozen within a short duration after being caught and stored at -20°C (-4°F), it can remain in top condition for up to 8 months.
However, when stored at -15°C (5°F), , it only remains in good condition for roughly one month. Small temperature differences matter — and this is exactly why the best way to ship frozen seafood involves consistent, microprocessor-monitored temperature control rather than passive cooling alone.
2. Package them well
Ensure you carefully consider key elements when choosing the packaging:
- Select durable, watertight packaging with insulation.
- Prevent any leakage and eliminate as much air from the package as possible, regardless of the container type you use.
- For live shellfish such as crab, use containers like insulated totes or wetlock cartons, marked with “This Side Up” labels.
- Seal and secure containers with strapping tape, or a similar material.
Photo by Алекке Блажин
3. Choose the right design of packing containers
Container packaging is typically used to transport fresh or frozen seafood. These sturdy containers can come in different shapes, a two-piece wax box, foam box, fold-up box, or even a plastic cooler.
To decide which packaging box is most suitable, consider:
- Whether it will be shipped as frozen or fresh?
- Whether the seafood will be cut to size or left as a whole?
Overall, containers should be designed to keep seafood delivered at a temperature that is no higher than 0°C (32°F), though preferably below -5°C (23°F).
For offshore and international routes, DNV-certified reefer containers — a type of temperature-controlled shipping unit built to withstand harsh marine environments — offer a more reliable solution than standard packaging.
It’s recommended to include about five inches of suitable insulation. The insulation must be light, with low thermal conductivity and resistant to moisture penetration—for example, aluminium-backed foam.
4. Use refrigerants when needed
When transporting frozen seafood, refrigerants aren’t really needed as the frozen nature and ice keep them safe for the entire trip. However, when shipping fresh seafood, you will undoubtedly require a refrigerant like gel ice, wet ice, or dry ice.
Quick definitions:
- Gel ice: reusable packs filled with a gel substance that stays cold for extended periods; best suited for short-haul fresh seafood shipments.
- Wet ice: standard crushed or block ice; effective but can cause water damage if not properly contained.
- Dry ice: solid carbon dioxide at -78.5°C (-109.3°F); ideal for keeping products frozen during longer transit times. Requires ventilation because it sublimates into CO₂ gas.
5. Give proper labelling and marking
Packages should always be labelled with indelible inks and waterproof labels while remaining properly sealed. Sometimes, a ‘Fish/Wildlife’ sticker may also be used by the shipper. Typically, the following items are displayed on each shipment:
- Name and address of shipper/consignee
- 24-hour phone number of the consignee
- Species name (eg., king salmon)
- Sticker noting commodity as Fish or Wildlife
- Number of each species, or the weight of each type
- Each container clearly marked Live, Fresh or Frozen
6. Understand the international regulations for shipping seafood and perishables
When considering shipping seafood, it’s important to get acquainted with the different regulations governing perishable transportation. Handbooks like the Perishable Cargo Regulations (PCR) manual exist (depending on your territory) that you can reference for guidance on shipping perishable items like fresh seafood.
For example, some regulations dictate that a shipment is perishable if its contents deteriorate over a specific period of time when exposed to harsh conditions, like humidity or extreme temperatures.
7. Use proper shipping routes
On average, it takes a carrier about 10–24 hours to reach their destination. If you need to know how to ship seafood overnight, the key is selecting express or next-day freight services and packing with enough dry ice or gel packs to maintain safe temperatures for at least 24–36 hours. Ensure you use the right materials to package your seafood, with sufficient protection and refrigeration to maintain a frozen environment during transit.
8. Get proper documentation
Always ensure you have the appropriate documentation to ship seafood:
- Shipper’s Export Declaration
- Shipper’s Certificate for live animals
- Airway bill
- Certificate of origin
- Commercial Invoice
- Healthy Inspection Certificate
- CITES Certificate
- Insurance Certificate
9. Get your shipments insured
Your carrier should allow you to purchase additional shipping insurance on top of your shipping cost. This additional insurance comes in handy as specific types of seafood are high-value items and expensive to replace. They’re worth protecting with shipping insurance during transit.
Choosing the right offshore reefer container is one of the most important decisions in how to transport seafood safely over long distances.
MGS’s Ice Storm and Ice Wave (both DNV 2.7-1 certified) feature microprocessor-controlled temperature settings from -30°C to +20°C, built-in data loggers, and humidity control, giving you full cold chain visibility from port to platform.
The importance of partnering with a reputed offshore reefer container agency
Since seafood is very sensitive, you should understand which type of refrigerated containers is best for your seafood shipment needs.
An offshore reefer container is a DNV-certified, temperature-controlled shipping unit designed specifically for use in marine and offshore environments (including oil rigs, FPSOs, and remote coastal facilities) where standard refrigerated trucks can’t reach. The best offshore reefer container agencies should offer:
- DNV and ISO-certified offshore reefer container purchase and rental options.
- Expertise in shipping seafood and other temperature-sensitive products to offshore locations.
- Tie-ups with an overnight shipping service so that seafood can be delivered the next day.
- Round-the-clock reefer container maintenance and technical support.
- Automated temperature and ventilation monitoring as offered by DNV offshore reefer containers.
- Real-time tracking of containers during transit.
- Customized offshore reefer container that can cater to your various shipping requirements.
Choosing a good offshore refrigerated container for transporting seafood could be one of the most important factors in assuring product quality when it reaches its location.
MGS offers modern DNV-certified offshore catering freezers, with advanced features that ensure that your seafood is shipped under optimum conditions across Europe, Africa, Asia, the Americas and Oceania.
Key features include microprocessor-controlled fresh air exchange, patented insulation foam rated for zero ozone depletion, a built-in data logger that tracks cargo temperature in real time, and a humidity control system with a dehumidification range of 65%–85%, all designed to keep perishable cargo at its target temperature throughout transit.
Check out Ice Storm and Ice Wave– two DNV certified products offered by MGS for your offshore transportation needs.
Frequently Asked Questions About Shipping Seafood
How is seafood transported?
Seafood is transported using refrigerated trucks, air freight, insulated packaging with dry ice or gel packs, and offshore reefer containers, depending on the distance and destination. For offshore and intercontinental routes, DNV-certified reefer containers with microprocessor temperature controls are the industry standard for maintaining cold chain integrity.
How long can seafood stay unrefrigerated?
According to the FDA, seafood should never be left unrefrigerated for more than 2 hours. If the ambient temperature is above 32°C (90°F), that window drops to just 1 hour before bacterial growth reaches unsafe levels.
How long can seafood last without refrigeration?
Unrefrigerated seafood becomes unsafe within 2 hours at room temperature. Bacteria that cause foodborne illness multiply rapidly between 4°C and 60°C (40°F–140°F), a range the USDA calls the “Danger Zone”, so time without refrigeration should be treated as the single biggest risk factor during transit.
How long can seafood be refrigerated before it goes bad?
Fresh seafood stored in a refrigerator at 4°C (40°F) or below should be used within 1–2 days of purchase, according to FDA guidelines.
Frozen seafood stored at -18°C (0°F) or colder can remain safe indefinitely, though quality is best within 4–8 months, depending on species and storage conditions.
How do I ship frozen seafood?
To ship frozen seafood, pack it in puncture-resistant plastic bags (at least 4mm thick), remove excess air, seal with zip-ties, and place inside an insulated container with dry ice. Use the H-taping method on the outer corrugated box.
For large-scale or offshore shipments, use a DNV-certified reefer container, like the MGS Ice Storm or Ice Wave, set to -20°C or below to maintain quality for up to 8 months.
Conclusion
The worldwide consumption of seafood is steadily increasing due to advances in aquaculture and the recognisedpresumed health benefits of seafood.
This means that it’s more imperative than ever to keep seafood safe and consumable during transit with suitable coolant, containers and packing methods.
The best way to ship seafood — whether fresh, frozen, or live — comes down to temperature control, proper packaging, the right documentation, and a reliable cold chain partner.
To ensure an optimal cold chain is maintained, keep the following points in mind:
- Use leak-proof plastic bags and seal them properly.
- Always place seafood in a portable refrigerator.
- Packaging should always be in well-built sturdy containers/boxes
- Temperatures below 4°C (40°F) for fresh seafood and below -18°C (0°F) for frozen shipments.
- Pack food with dry ice or a suitable cooling material.
- Always use clear, waterproof labels.
- Choose DNV-certified offshore reefer containers, like MGS’s Ice Storm or Ice Wave, for offshore and intercontinental transportation.
Business Director
A graduate (Business) from KDU, Jason Tan, is the current Business Director (Sales) for MGS Icestorm and has been associated with the company for the past 10 years.
With over 13 years in the shipping industry, he has had a significant contribution to Malaysia’s oil and gas industry in the engine and boat supply sector.
His expertise includes managing offshore catering business, offshore reefer containers, AI technology, offshore gas tanks, A60 pressurized cabins, etc. His contributions have helped establish MGS, in partnership (joint venture) with Thermo King and Honeywell to produce state of art Offshore Reefer Container products.