Véronique Le Bihan

OYSTER FARMING AND EXTERNALITIES: THE EXPERIENCE OF THE BAY OF BOURGNEUF

The history of the French shellfish industry is marked by a series of overfishing crises occurring in most of the open-access shellfish beds. When the concession system was introduced (1852), it was designed to cope with congestion and overfishing issues more than with the development of shellfish culture. After closing the production cycle in the late 19th century, the oyster industry kept suffering major crises such as massive disease outbreaks. Their occurrence can be analyzed in terms of overexploitation resulting from environmental externalities. We will show that this can create a backward-bending supply curve for oysters, using the Bay of Bourgneuf as a case study. In this bay, 400 firms, mostly family-sized, are being conceded 1,000 ha and sell 10,000 tons of Crassostrea gigas oysters a year. The paper presents a typology of farmers based on a survey that shows that farmer behavior can be aggregated into three main groups.

A comparative appraisal of the resilience of marine social-ecological systems to mass mortalities of bivalves

In many parts of the world, both wild and cultured populations of bivalves have been struck by mass mortality episodes because of climatic and anthropogenic stressors whose causes and consequences are not always clearly understood. Such outbreaks have resulted in a range of responses from the social (fishers or farmers) and governing systems. We analyzed six commercial bivalve industries affected by mass mortalities using I-ADApT, a decision support framework to assess the impacts and consequences of these perturbations on the natural, social, and governing systems, and the consequent responses of stakeholders to these events. We propose a multidimensional resilience framework to assess resilience along the natural, social, and governing axes and to compare adaptive responses and their likelihood of success. The social capital and governability of the local communities were key factors affecting the communities’ resilience and adaptation to environmental changes, but the rapid degradation of natural ecosystems puts the bivalve industry under a growing threat. Bivalve mariculture and fishing industries are likely to experience increased frequency, severity, and prevalence of such mass mortality events if the resilience of the natural systems is not improved. An understanding of previous adaptation processes can inform strategies for building adaptive capacity to future events.