By-products (co-products or rest raw materials) – an incidental or secondary product made in the manufacture or processing of a fish product. Examples of fish by-products are heads, skins, bones and viscera.

Discards - Discards are the portion of the total catch which is thrown away or slipped. Discards may be comprised of single or multiple species and may be alive or dead.

Economic value of loss – Economic value is the maximum amount a consumer is willing to pay for an item (e.g. fish or fish product). Fish loss and waste represents a loss of economic value for actors in the food production and supply chains. The monetary values of physical and quality loss are combined to give the total financial loss, which is used to quantify and summarize overall losses incurred by an individual or group in a particular fishery or distribution stage. For example, a fisherman may experience more than one type of loss at the same time. He may sell some fish for a reduced price and also throw away some fish from the same catch.

Fisheries management – Fisheries management should promote the maintenance of the quality, diversity, and availability of fishery resources in sufficient quantities for present and future generations in the context of food security, poverty alleviation and sustainable development. Management measures should not only ensure the conservation of target species but also of species belonging to the same ecosystem or associated with or dependent upon the target species.

Food loss and waste (FLW) – is “the decrease in quantity or quality of food”. Food waste is part of food loss and refers to discarding or alternative (non-food) use of food that is safe and nutritious for human consumption along the entire food supply chain, from primary production to end household consumer level. Food waste is recognized as a distinct part of food loss because the drivers that generate it and the solutions to it are different from those of food losses.

Micronutrients – minerals and vitamins required in very minute amounts. Together, they are extremely important for the normal functioning of the body. Their main function is to enable the many chemical reactions to occur in the body. Micronutrients do not function for the provision of energy.

Net to plate – similar to the term farm to fork referring to agricultural production, “net to plate” refers to the various activities and processes from fish production to final consumption.

Physical loss – fish which is completely lost and not utilized for either food or non-food use.

Poor handling – practices which cause spoilage, damage or food safety concerns.

Post-harvest losses –   measurable quantitative and qualitative loss in a given product. These losses can occur during any of the various phases of the post-harvest system.

Quality loss - is the difference between the potential value of fish or fish product if no deterioration had taken place (best quality) and the actual value of the fish after it had undergone change due to spoilage (lower quality) and was sold for a low price. Quality loss cannot be adequately expressed in weight terms alone. This is because, in many cases, the proportion of a batch of fish that has suffered a loss in quality still has some residual value.

Spoilage – the bacterial or enzymatic breakdown of fish protein.

Supply chain management (SCM) – the broad range of activities required to plan, control and execute a product's flow, from acquiring raw materials and production through distribution to the final customer, in the most streamlined and cost-effective way possible. 

Value chain – a value chain is the full range of activities that are required to bring a product or service from its conception to the final consumers. This includes activities such as design, production, marketing, distribution and support services to the final consumer. Value chains can be restricted to local markets, but do also expand globally. In fisheries this includes fishing, aquaculture, processing, transport, wholesale marketing and retail marketing.

Waste – waste is the component of fish loss and waste that occurs when edible fish or fish product goes unconsumed or is discarded. It is also known as “physical loss” (see above).