Récolter la mer Des savoirs et des pratiques des collecteurs d’algues à la gestion durable des ressources côtières dans le Finistère (Bretagne)

After several cycles over the course of past centuries, seaweed harvesting in Finistere is once again experiencing a revival and emerging as a promising sector. Beyond socio-economic transformations, it is also faced with current issues of biodiversity conservation and the sharing of maritime space. How can human activity and preservation of the environment be reconciled?
The mobilized ethnoecological approach looks at resource management by local communities through their engagement - practices, traditional ecological knowledge, and representations. The aim of this thesis is thus twofold: understanding the dynamics of seaweed harvesters' engagement, and understanding how they mobilize and cope with current issues.
Through ethnographic survey and ethnoecological methods, the scientific, social, and administrative frameworks were investigated diachronically to understand the context and the issue. The identity of the collectors were studied through both 'administrative statuses' as well as five profiles that emerged from the data. This diversity in forms of engagement is reflected in the sensory perceptions mobilized during harvesting, in the vernacular classifications of seaweed, and in how space is apprehended. The analysis of these three dimensions reveals a rich body of 'intimate', 'embodied', and 'situated' knowledge that is inextricable from practices relating to seaweed, aquatic environments, and ecosystem dynamics.
Finally, various elements across knowledge and representations shed light on conflicts and illustrate the influence of science and industry on collectors. The climate event that took place during the winter of 2013–2014, for example, left an impact on seaweed resources and forced collectors to adapt. It revealed the interplay between actors of the various sectors and the composite (or even hybrid) nature of their engagement, a first step towards co-management.

Keywords: ethnoecology, ethnophycolgy, seaweed harvester, Brittany, vernacular classification, practice, traditional ecological knowledge, seaweed, sustainable