A stakeholder is an individual, group or organization that is impacted by the outcome of a project. They have an interest in the success of the project, and can be within or outside of the organization that is sponsoring the project. Stakeholders can have a positive or negative influence on the project.

In a sector such as aquaculture, where there are likely to be multiple stakeholders, the ability to differentiate between primary and secondary stakeholders is crucial. Omission of primary stakeholders, failure to clearly define and identify primary and secondary stakeholders, or defining participation boundaries too broadly increases the likelihood of conflict, makes decisions difficult to achieve, and/or compromises decision quality.

There are often high expectations that, by involving stakeholders, more realistic and effective aquaculture policies and plans will be formulated and their implementation improved. In the context of climate change site-selection for new farms and the management of extant ones could mitigate these potential impacts, but the implementation of this planning process is dependent on stakeholder support and engagement. 

The stakeholders implicated in the management of the mussel farming activity in the Thermaikos Gulf belong to three major categories:

1. The people working at the sector of mussel farming

2. The representatives of the public institutions

3. The scientists that are working in aspects of the mussel farming activity