Globally, aquaculture now plays a significant role in aquatic food production, due to high demand and the limits reached by the supply from fishing. Monospecific aquaculture, particularly oyster farming, has faced sustainability challenges over the years with regular crises. Species diversification is proposed as a means to enhance the sustainability of farms, especially to support activities in the context of global change.
In Brittany, located at the westernmost part of Europe, three diversification strategies (see below) are being tested in the oyster farming sector as part of innovation research projects conducted in collaboration between professionals and scientists (financial support from the EU and the Brittany Region). The aim of this presentation is to report on some recent or ongoing work.
New species association. The combination of the abalone, Haliotis tuberculata , and the sea cucumber, Holothuria forskali, was tested. The latter, being a detritivore, could benefit from the deposits from the abalone’s activity. The experiment, conducted over 9 months, demonstrates the potential of combining two species without additional inputs or labor (Figure 1).
New spaces . This involves proposing offshore oyster farming (Magallana gigas ) that is less dependent on continental vicissitudes and requires less labor. Compared to conventional intertidal farming, the survival rate and flesh yield in open sea conditions are significantly higher (Figure 2) .
New product range. Th e aim here is to a high-end, small-size product with a high flesh yield and distinctive organoleptic qualities to attract new consumers. To achieve this, the technical route was shortened to reduce mortality, and environmental conditions were selected to optimize weight growth.
This work shows the potential for diversification in the oyster sector with the goal of improving the competitiveness of businesses and their resilience to upcoming environmental disturbances.