There is not an only internationally accepted definition of traceability for foodstuffs and, in particular, for fish products, as some theoretic and practical difficulties with this concept have arisen.

Nevertheless, we could say that traceability is the ability to know the history of a certain fish product from its catch to the consumer (“from ship to dish” or “from farm to fork”).

We can even find a few useful definitions from standardization and legislation bodies, which will help us to better understand the implications of this concept when dealing with seafood:

International Organization for Standardization (ISO)
The organisation should take steps to identify the status of the product/service insofar as concerns the required measurement and verification activities and should, where necessary, identify the product and/or service using the appropriate means throughout the process. This should apply to all parties involved in the product and/or service where their interaction has a bearing on the conformity to requirements. When traceability is a requirement, the organisation should control and record the unique identity of the product and/or service

ISO 9000:2000, Quality management systems - Fundamentals and vocabulary
7.5.2. Identification and traceability

Many companies still refer to ISO 8402:1994, which was replaced by ISO 9000:2000:
Traceability is the ability for the retrieval of the history and use or location of an article or an activity through a registered identification.
ISO 8402:1994 Quality management and quality assurance - Vocabulary

Codex Alimentarius
The ability to identify a food (product identification), how it was changed (if appropriate), where it came from and where it was sent (one step backward and one step forward) (product information) and the linkages between product identification and product information, while also nothing that the applicability of these elements will depend on the objectives being pursued by the individual texts.

Codex Committee on food import and export inspection and certification systems (CCFICS). Sesion 11, Adelaide, Australia, 2-6 December 2002. Agenda item 7, CX/FICS/02/11/7 paragraph 7.

European Commission
“The ability to trace and follow a food, feed, food-producing animal or substance intended to be, or expected to be incorporated into a food or feed, through all stages of production, processing and distribution”.
Regulation EC 178/2002 FOOD LAW

Systems for traceability are not completely new for the fishing industry, as many of them worldwide have already been implementing systems partially or totally related to traceability (ex. Stock management of either raw material, interim or final products; Designation of origin, etc.). Good examples of this are the labelling systems, although they are not exactly the same. Labels must bear permanent and one-to-one recognized information, but it is not enough for traceability, as this goes beyond the information kept in labels.

In defining traceability, it also is important to distinguish between the terms tracking and tracing.
Tracking is the capability to follow the path of a specified unit and/or batch o of trade items downstream through the supply chain as it moves between trading partners. Trade items are tracked routinely for availability, inventory management and logistical purposes.
Tracing is the capability to identify the origin of a particular unit located within the supply chain by reference to records held upstream in the supply chain. Units are traced for purposes such as recall and complaints. (at EAN.UCC Traceability Implemantation Guideline, at www.ean-int.org/agro_food_safe.html )

Nowadays there are detailed requirements for traceability gathered in specific regulation, which generally binds stakeholders to keep registers according to “one step forward and one step back”. This scheme implies maintaining registers of purchasing and distribution, as well as of internal changes produced within the establishment or industry.

When thinking about traceability, what industry, public administration and scientists should keep in mind is that it is not a final aim itself, but it should be considered as a mean to protect consumers’ health and to ensure the use of good practices in food production and commerce.
The first aim of any food traceability system is the consumer’s protection.