The sustainable development of seas and oceans rests on three traditional pillars that form the backbone of this concept (i.e., economic development, environmental responsibility, and social progress) [
22]. In the EU marine context, economic development is attributed to the concept of blue growth [
23] defined as ‘smart, sustainable and inclusive economic and employment growth from the oceans, seas and coasts’ [
24]. Formulated at the Rio + 20 Earth Summit in 2012, the concept came as a response to the need to eradicate poverty [
25]; nowadays, it represents one of the key EU economic strategies [
26]. The
Marine Strategy
Framework Directive (MFD), which aims to achieve a Good Environmental Status (GES) of the EU’s seas and oceans [
27], provides the crucial element of environmental responsibility. Several scholars underline mismatches, tensions, and discrepancies between these two approaches (i.e., MFD and blue growth) [
28,
29]. The social sustainability of maritime spatial development has not been addressed directly and only partially indirectly through the EU MSP Directive [
6]), which encourages the participation of various stakeholders in the MSP process. This directive also underlines the importance of co-existence. Thus, while social sustainability at sea has not been conceptualised in formal documents of EU legislation, its essence was recently outlined by MSP researchers [
26]. They have identified Recognition, Representation, and Distribution as interdependent and interwoven building blocks that, together, contribute towards conceiving social sustainability as a pillar of sustainability at sea. This first element means recognition of (respect in relation to) the diversity of group identity (and related socio-cultural rights, needs, livelihoods, lifestyles, and knowledge). The second one concerns inclusion in and exclusion from the decision-making process. The third one covers the distribution of goods and bads as a result of the governance process.
The situation outlined above makes clear that maritime sustainable development encapsulates multiple expectations and demands, such as GDP growth and employment, poverty alleviation, ecological sensitivity, as well as respect for spatial justice and diversity. Any trade-offs between those dimensions require deliberation through a process of public choice [
30]. Multi–use may help juxtapose the aforesaid dimensions of sustainable maritime development. Thus, it should be considered in various marine governance processes, including the MSP, as the actions pursued in agreement with the aims of these dimensions will ultimately convert into various spatial demands and arrangements.