Fish is a highly perishable commodity and, if not handled properly, quality deteriorates which can have detrimental consequences for the health of consumers. At the beginning of the 21st century, over 75 percent of the fish produced was used for direct human consumption while the remaining 25 percent was reduced to fishmeal and oil. Of the fish destined for direct human consumption, the volume marketed as fresh fish nearly doubled during the 1990s. Fresh fish is now the most important fishery product (over 40% of the market), followed by frozen fish (about 30%), canned fish (about 14%) and cured fish (12%). With almost a third of world fish production now being traded internationally, quality and safety assurance has become a major issue.
The generally acknowledged limits of production from capture fisheries, coupled with the widening gap between the supply and demand of fish for human consumption, reaffirms that post-harvest losses are an unacceptable waste of scarce natural resources. Post-harvest losses of fish occur in various forms. The physical loss of material is caused by, for example, poor handling and preservation or the discarding of bycatch. Economic losses occur when spoilage of wet fish results in a value-decrease or when there is a need to reprocess cured fish, raising the cost of the finished product. In addition, inadequate handling and processing methods can reduce nutrients, leading to nutritional loss. Similarly, the lowering of large quantities of fish catches into animal feeds can be considered under certain conditions as a "loss" for human food security.
Post-harvest losses in small-scale fisheries can be among the highest for all the commodities in the entire food production system. Fish losses caused by spoilage are estimated at 10 to 12 million tonnes per year, accounting for around ten percent of the total production from capture fisheries and aquaculture. Appropriate preservation methods can significantly reduce this loss, including from glut catches when the processing, distribution and marketing system cannot cope with the exceptional quantities of fish that are sometimes landed due to seasonal or inter-annual variations of availability or abundance.
Considerable progress has been made in recent decades to establish international agreed standards and procedures that assure consumers a good quality fish products. Also World Trade Organization (WTO) members have agreed sets of rules designed to prevent states using quality and safety issues as trade barriers. However, problems arise in the use of these standards, procedures and rules. The hazard analysis critical control point (HACCP) system, a systematic and preventive approach for the assurance of food safety and quality, is now accepted worldwide as the most cost-effective system for quality and safety assurance and has been made mandatory in many countries. But differences arise in the way the system is implemented in practice.
The Codex Alimentarius of FAO and the World Health Organization (WHO), created in 1963, is a voluntary code establishing international standards for food safety and quality. The agreements on Technical Barriers to Trade and on Sanitary and Phytosanitary Measures recognize the Codex Alimentarius Commission as the international standard-setting body for food safety and encourage member countries to use Codex standards to facilitate international harmonization and fish trade - although much remains to be done to achieve international harmonization and to develop equivalence framework.