Local ecological knowledge (LEK) can be considered as a knowledge system which can be conceptualised as knowledge held by a certain group of people on their local ecosystem. Taking a closer look at this general definition, reveals that LEK contains multiple attributes.

Local ecological knowledge can be considered as a form of 'ecological knowledge’ referring to knowledge of the ecosystem, in particular: seasonal and fish movement, spatial patterns in fish morphology … . Hereby, it is important to indicate that knowledge is not an objective concept. Knowledge is particularly liable to influences such as institutional changes, social and cultural change, but also to the way it is gathered and passed on. Knowledge lies within a social context and inevitably both are influencing each other. Therefore LEK is observed as a social construct. The concept of "local" in this study refers to the spatial dimension, and the local environment. In essence, LECOFISH concentrates on the Belgian Part of the North Sea (BPNS). The reason for this approach is the proposition that fishermen have a detailed knowledge concerning this region.

As mentioned above, LEK is a form of ecological knowledge. In the current literature other general forms of ecological knowledge are also referred to as 'Traditional Ecological Knowledge’ (TEK), and 'Indigenous Ecological Knowledge’ (IEK). In addition, other forms exist and because they can be categorised in these three general forms, they are left aside. The emphasis by IEK lies on culture, indigenous people and tribes. In TEK the historical and cultural continuity in the use of the resources is stressed. Furthermore, there is a pool of knowledge obtained by learning from experience, family and the community. In this project we will use LEK. The definition of LEK can be interpreted as broad and neutral. Here we start from the position that LEK contains TEK. Firstly LEK lies within a social context in which the interaction between the two occurs. Knowledge is not only created by personal experience or by the community, but also by external factors such as legislation, technological development, political, and economic interests. A second reason is the argument that the word ‘local’ does not necessarily refer to 'traditional' as with the commercial fisheries. This study also involves recreational fishing from the assumption that they also hold knowledge regarding the marine ecosystem. A final reason is that the marine ecosystem and the knowledge about the marine ecosystem is also determined by additional anthropogenic activities at sea such as dredging, shipping, etc...