**1. Introduction**

The small (178km2) Greek island Samothraki ("Σαμoθρα´κη") in the Northern Aegean Sea (Figure 1) finds itself in a situation of transition between being dominated by traditional agriculture (mainly herding of small ruminants) and tourism. The island hosts a unique ecological diversity, mainly because of its rich water resources and its heterogeneous landscape. Along the island's stream courses and around the natural crystal-clear waterfalls and pools abound old oriental plane forests, while pristine old growth oak populations still persist at the hills of the central Saos-massif (1611m) [1,2].

*Sustainability* **2020**, *12*, 1932

**Figure 1.** (**a**) Physical map of the island Samothraki [3]; (**b**) view from the NW.

Samothraki has been inhabited since prehistoric times and the fabric of the present society is still shaped by its history (www.sites.google.com/view/samothraki/history, accessed on December 2019). The most celebrated part of this history is represented by the remains of the "Sanctuary of the Great Gods", a site of important Hellenic and Pre-Hellenic religious ceremonies. There, the Samothrakian or "Kavirian" Mysteries [4] took place, enigmatic rites open to both slaves and free people, even children. Herodotus and Pythagoras, for example, have taken part in them. In the fourth century BC, Philip II from Macedonia occupied the island; he is said to have met his wife on the Saos mountain, to later become father of Alexander the Great. During the Roman imperial period, Samothraki became an international religious center where pilgrims flocked in from all over the Roman world. The Bible records that Apostle Paul, in the first century CE, sailed on a missionary journey to Samothraki (www.sites.google.com/view/samothraki/history, accessed on December 2019). After a phase of Byzantine and then Genoan rule, Samothraki was conquered by the Ottoman Empire. An insurrection during the Greek War of Independence (1821–1831) led to a massacre of local population, in response to their refusal to pay taxes. Following the Balkan Wars, the island came under Greek rule in 1913. In the 1950s and 1960s, local poverty drove out a large number of men and families seeking work in the German automobile industry (In the Stuttgart area, there still exists a large and active cultural association of Samothrakians, many of whom are also entitled to vote on the island in local elections [5].) (Figure 2). They brought home money as well as knowledge of the language and the German industrial culture. During the time of military dictatorship in Greece (1967–1974), Samothraki was a place of exile for political dissidents. Thus, the history of this island has been marked by singular cultural and political features, and repeated population shifts.

In the decades after World War I, the local population had been growing to a peak of 4200 people. It then strongly declined and increased again with beginning tourism in the early 1980s (Figure 2).

Socioeconomically, the resident population gradually shifted from the primary sector towards the tertiary sector (Figure 3). Currently, there is a large group of poorly educated (sometimes illiterate), predominantly elderly farmers and a few fishermen leading a traditional lifestyle with little contact to outsiders. The secondary sector represents only a small and lately decreasing fraction of the island's economic activity. There is one olive press, a dairy, a small winery, a beer brewery, and several bakeries, as well as some construction and mining activity. There also used to be a municipal wheat mill. In contrast, the tertiary sector has grown substantially during the last decades and now employs 60% of the island's workforce. This better educated and more informed part of the population is working mostly in the service sector, tourism, and administration.

To a visitor in the early 2000s, Samothraki appeared as a place of overwhelming archaic, largely untouched, natural and cultural beauty, but also endangered. Scientists had already been engaged in recording the island's aquatic quality and aquatic/terrestrial biodiversity, and found it highly impressive but under threat, although the majority of stream basins illustrate reference ecological conditions [1,6]. How could further research contribute to secure the unique natural qualities of this island? This would presuppose to create a vision and an identity for the community on this island that would frame the local conditions not as "backwardness", poverty, and lack of modernity to be overcome, but as a worthy heritage and asset to be developed in a targeted way. It could only be successful if the local population would identify and be able to anticipate clear benefits from such a vision, benefits that would outweigh negative trade-offs. The concept that seemed best attuned to pursuing a pathway of both nature conservation and socio-economic benefits through sustainable social use of ecosystems appeared to be UNESCO's Biosphere Reserve concept [7]. (Biosphere Reserves are areas that encompass valuable ecosystems and social communities that wish to combine the conservation of ecosystems with their sustainable use. They are nominated by national governments and remain under sovereign jurisdiction of the states where they are located, but become internationally recognized by UNESCO. Biosphere reserves form a World Network under the protection of UNESCO. Within this network, exchange of information, experience and personnel are facilitated. At present, there are about 700 biosphere reserves in over 120 countries (See: http://www.unesco.org/new/en/natural-sciences/environment/ ecological-sciences/biosphere-reserves/)). This idea built upon the fact that over three-quarters of the island's surface had been already designated as a Natura 2000 conservation area. Our team started a first research effort in this direction in 2007 to find answers to the following questions: Does the island of Samothraki provide adequate natural, social, and economic opportunities for a pathway of nature conservation and sustainable development as envisioned in the UNESCO Biosphere Reserve concept? Is the vision of becoming a Biosphere Reserve attractive to local (and regional) stakeholders? Does it offer containment and an identity that is welcome and promising? These questions were dealt with a literature and data review, and a representative survey (N=1511) of residents and tourists [8] leading to positive conclusions: The island's landscape and biodiversity proved to be quite exceptional and highly worthy of protection; second, the local population, and even more so the tourists, gave

support to a conservationist rather than a modern industrial developmental course. The outcome was a unanimous decision of the local municipal council in favour of an application to UNESCO. Scientists from the Institute of Social Ecology from Vienna helped to prepare the application form, and it was formally submitted as signed by the Mayor and other responsible Greek authorities in 2013 [9]. Unfortunately, though, it turned out that the Greek state had not ye<sup>t</sup> fulfilled the legal and managerial preconditions associated with Natura 2000; thus, the application was deferred by UNESCO on the grounds of insu fficient legal protection of the core conservation areas. This backlash made clear that it would take a longer breath, a more systemic perspective in research, as well as stakeholder mobilization and the building of policy alliances [8]. In other terms, we were heading for a "real world lab" to achieve a sustainable pathway for Samothraki [10,11].

#### **2. Heuristics and Methods**

In order to be able to influence development dynamics, it seems appropriate to look upon islands as complex socio-ecological systems. In island studies, this perspective is not so common [12–14]: Rather, there is a focus on particular problems such as food security [15], migration [16], or overgrazing [17]. Guiding local sustainable development means to understand the conditions under which socio-economic activities can support the quality of life and the income of the islanders while sustaining (or even improving) the quality and resilience of the natural environment. Such a comprehensive research question can best be addressed by focusing on the exchange relations between the respective socio-economic sectors and the local environment with the help of a heuristic sociometabolic model [18,19] as outlined in Figure 4, specified for the case at hand.

**Figure 4.** Sociometabolic system model for the relevant stocks and flows within and between the local society and its natural environment. [20] (p.14).

When critical stocks cannot be reproduced, the system might 'collapse' [21,22]. Briefly said, a balanced sustainable development implies not to increase socio-economic stocks excessively, using natural resources carefully and e fficiently, creating e ffective synergies between the sectors of the economy, and using commons with fairness and responsibility [18,23]. Across the years of research, this model served as a mind map for what matters for the sustainability of the island, and guided the selection of variables to be measured, the interrelations to be analyzed, and the attention for critical

thresholds. In the core area of the model figures the human population (both residents and visitors) and their involvement in the three socioeconomic sectors: Agriculture and fishing, tourism services, and local public services (administration, schools, medical, care, and technical services). The sectors control certain biophysical infrastructures (animal livestock, built infrastructure, technical infrastructures). They draw on certain natural resources and generate wastes and emissions. They require human labor power and provide economic benefits. All these processes are subject to cultural and legal guidance, which they in turn influence across time.

Beyond this, such an island system is of course strongly linked to the outside world: Economically, to the Greek state, the European Union (Common Agricultural Policy, EU-CAP in brief, subsidies), and to the income the tourists earn somewhere else and spend on the island. Politically, legally, and culturally, it depends on the overall situation in Greece and beyond, and its natural conditions depend on broader environmental change (such as global warming). All these interrelations matter for finding a sustainable course. Across the years, the research team sought to operationalize quantitatively all stocks and flows shown in Figure 4. Beyond this, it documented their environmental impacts, and supported local stakeholders in finding solutions (responses). For a better understanding of this multi-method approach, Table 1 provides an overview structured according to the more conventional DPSIR—drivers, pressures, states, impacts, responses—framework [24].

The research process across more than a decade built upon yearly summer schools, each organized in collaboration between universities, research institutions, local and national authorities, NGOs, and UNESCO branches, with about 150 students altogether, from more than 20 countries and 40 universities [7,20,25–27]. The summer schools were designed in such a way that in each of them—depending on the scientific background and the research interests of the respective institutions and students participating—addressed certain research tasks contributing to the overall research question and helped to achieve maximum synergistic e ffects between learning, research, and addressing policy goals for local development. At the same time, they showed our continuous presence on the island to numerous locals, members of the municipality, and the regional administration. Part of our research also involved local so-called citizen scientists in ongoing explorations, thus feeding back our findings to stakeholders and the island's public. A small producer visualized this research process across several years in the film "Wings of Samothraki" in English and Greek. (www.sustainable-samothraki.net/activity/wings-of-samothraki/, accessed on December 2019).

This article attempts a synoptic view of the findings accumulated so far. The results presented are structured according to the two core sectors of the island's economy, agriculture and tourism, their development dynamics, and their environmental impacts. In the discussion, we place these findings in a broader perspective on the island's chances of a comprehensive sustainable course, and the role of scientific research in its support.

**Table 1.** Overview of research questions, indicators and methods used, according to the drivers, pressures, states, impacts, responses (DPSIR) framework [24].

