There are many different types of fishing vessel used throughout the world. They have evolved in particular regions to take account of the prevailing economics, environment and types of fish and shellfish caught or harvested. However, the Code Of Practice For Fish And Fishery Products highlights the basic requirements for cleanability, minimizing damage, contamination and decomposition to which all vessels should have regard to the extent possible in order to ensure hygienic, high-quality handling of fresh fish and shellfish and hence minimize FLW. The following summarizes relevant aspects of the Code:

For ease of cleaning and disinfection

• Vessels should be designed and constructed to minimize sharp inside corners and projections in order to avoid dirt traps.
• Construction should facilitate ample drainage.
• A good supply of clean water or potable water at adequate pressure.

To minimize contamination

• All surfaces in handling areas should be non-toxic, smooth, impervious and in sound condition in order to minimize the build-up of fish slime, blood, scales and guts and to reduce the risk of physical and microbial contamination.
• Where appropriate, adequate facilities should be provided for the handling and washing of fish and shellfish and should have an adequate supply of cold potable water or clean water for that purpose.
• Adequate facilities should be provided for washing and disinfecting equipment, where appropriate.
• The intake for clean water should be located to avoid contamination.
• All plumbing and waste lines should be capable of coping with peak demand.
• Non-potable water lines should be clearly identified and separated from potable water to avoid contamination.
• Objectionable substances, which could include bilge water, smoke, fuel oil, grease, drainage and other solid or semi-solid wastes, should not contaminate the fish and shellfish.

To minimize damage to the fish, shellfish and other aquatic invertebrates

• In handling areas, surfaces should have a minimum of sharp corners and projections.
• In boxing and shelving storage areas, the design should preclude excessive pressure being exerted on the fish and shellfish.
• Chutes and conveyors should be designed to prevent physical damage caused by long drops or crushing.
• The fishing gear and its usage should minimize damage and deterioration to the fish and shellfish.

Many larger vessels capable of spending a day or more fishing will benefit from the use of some form of on-board preservation, such as ice, chilled seawater (CSW) and refrigerated seawater (RSW). Slurry ice is particularly effective at chilling fish quickly. It is a phase changing refrigerant made up of millions of ice "micro-crystals" (typically 0.1 to 1 mm in diameter) suspended within a solution of water, which contains a freezing point depressant (e.g. salt).  

For the full benefits of chilling to be realized, it is essential to maintain chill temperatures throughout the different fish-handling operations. Although ice can preserve fish for some time, it is still a relatively short-term means of preservation when compared to freezing, canning, salting or drying.

When used properly, ice can keep fish fresh so that it is attractive in the market place. The use of ice for preserving fish and fishery products has proved to be an effective handling method on board fishing vessels for the following reasons:

• Ice is available in many fishing areas or ports.
• Purchasing patterns can be varied according to need (e.g. block ice of different sizes is frequently manufactured, and crushed, small or fragmentary ice ready for use is sold by weight).
• Ice has a very high cooling capacity.
• Ice is harmless, and in general relatively cheap.
• Ice can maintain a very definite temperature.
• Ice can keep fish moist and as it melts it can wash surface bacteria from the fish.
• Ice can be moved from place to place and its refrigeration effect can be taken to wherever it is needed.
• Ice can be made on shore and used at sea.

Large boats are able to carry enough ice to make longer fishing trips, generally with better economic returns for the vessel and crew. With advances in refrigeration, in particular the advent of compact and relatively lightweight ice-making machines suitable for on-board installation, it is now possible to install ice machines of various types on vessels. This gives a certain measure of independence in fishing operations where trip length is no longer limited by the quantity of ice loaded in port or by how long it will last in the ice hold.

The use of ice in itself is no guarantee of a better product unless proper handling procedures are fully implemented before the fish are actually iced. The time between the capture and death of the fish to when they are properly iced must be as short as possible, with minimum exposure to high temperatures. In tropical conditions, this would also require that fish be kept in the shade and out of direct sunlight. On some vessels it is common to have a fixed or temporary canopy over the working deck which serves as a sun shelter for the crew and for the catch waiting to be processed prior to stowage.

The automation, or use of machines to assist with handling and processing of fish on board, is a means to reducing FLW. Automation of stunning, bleeding, sorting, filleting and weighing of the catch for example is seen to have the following benefits:

• Improved quality of the fish
• Shorter time period from catch to processing
• Improved environment, health and safety for the fishermen
• Reduce workload of fishermen
• Improve effectiveness – increased kg produced fish per fisherman
• Greater flexibility in product range
• Help achieve total utilization of by-products

Stunning and killing are two handling operations that are essential in order to establish a high quality in the catch after loading and holding. A stunned fish is motionless and this facilitates further processing of the catch on board. Inadequate bleeding leads to blood spots in the fillets. Immediate bleeding of live fish (or no later than 30 min post-mortem) can eradicate this problem.

Automated technology is also available to aid fishing vessels that need to comply with fishing control and traceability regulations. Vessel operators can register, certify and label their products in line with these obligations and demonstrate that fish is not illegal, unreported and unregulated (IUU). Benefits include improved supply chain management, documentation of sustainable management practices and easier compliance with labelling laws. Hence, improving market access and reducing the risk of product rejection and hence waste.