LAUSR

The present study aimed at evaluating the sustainability of ecological engineering solutions based on the introduction of the gastropod V. viviparus for maintaining the hydrological performances of infiltration basins clogged by benthic biofilms. This sustainability depends on the ability of gastropods to deal with variations in trophic resources throughout seasonal changes and so their feeding strategy. It is expected from literature that V. viviparus is a generalist species, well adapted for ecological engineering approaches. With this objective, laboratory and field experiments were developed to measure the ability of gastropods to maintain energy body stores under several food sources and seasons, in relation with their physiological state. Our results showed that V. viviparus was not a strict generalist: it tended to be more efficient to constitute energy reserves when feeding on algae under laboratory conditions and its energy stores were positively correlated with primary productivity of the benthic biofilm in the field. Despite this higher efficiency of V. viviparus to produce energy reserves from algal resources, the survival and the levels of energy reserves measured on the field, even when trophic conditions were the harshest (low algal development), make this species a good candidate for ecological engineering approaches.