Green Algae

In Lannion’s bay, the green algae have been a problem since the 80’s, as in most of the bays of Northern Brittany. This proliferation is not only causing losses of interest and economical benefits for the touristical activity for the communes of this beautiful coast. The green algae also create a direct sanitary danger because of the sulphuric gas produced by their decomposition on the beach. in 2009, a horse was killed by the gas produced and its rider was seriously intoxicated. A truck driver was also intoxicated and finally died.

Initially, the connection with cattle and pigs breeding was not established, this pollution being first imputed to urban phosphates. It is only in 1988 that the relationship between the algae proliferation and the nitrogen present in local rivers because of intensive cattle breeding in the region was established. In 1989, local newspapers began to report that “green algae could kill”. In this context, a local association of farmers promoting less intensive cattle breeding based of grassland (rather than on maize fodder, more nitrogen-demanding) took advantage of the situation and contributed in the 90’s to the creation of a agri-environmental EU measure promoting their grassland system. Nitrogen reduction in soft waters through grassland-based farming systems has been progressively promoted by all the local institutions related to farming questions.

A new action plan has been proposed (2011-2015). The main objectives are developing systems based on grassland on the catchment area and restoring wetland. Green algae continue to proliferate every summer in the bay, causing consequences on tourism. Though the shared efforts and the apparence of systemic change, the technical solutions proposed could not solve the problem. This case study has been chosen in order to illustrate and understand a situation of “failed transition” toward a (really) sustainable agriculture. The institutional interviews as well as farmers interviews aim to understand the long-term evolutions of agriculture in the bay since the 70’s, as well as the alliances evolutions observed, the resistances to change, the institutional compromises, the role of researchers and scientifical knowledge in the debate. Our hypothesis is that there is much to learn about transition processes by studying a failed evolution.