Détection précoce et lutte rapide contre la plante aquatique exotique Hydrilla verticillata (L.f.) Royle en Martinique

The problem of invasive alien species is increasingly being taken into consideration in Martinique, which seemed to have a certain resilience compared to other French tropical island territories. In this way, like nearly 70 alien and potentially invasive plant species, populations of Verticillate hydrilla (Hydrilla verticillata (L.f.) Royle) are monitored using mapping tools by the National Forestry Office, the Government Agency in charge of Environment and the Botanical Conservatory of Martinique. Following new distribution data reported by the existing monitoring network, a control campaign was conducted in 2016. In this island of French West Indies, the combination of steep reliefs, resulting from recent volcanic episodes, and rainfall patterns, induce a torrential regime of streams. We hypothesize that this torrential regime would cause the fragmentation of submersed macrophyte populations which would encourage their vegetative multiplication. Thus, in the context of early detection and rapid response, the eradication campaign against these plants must occur before the rainy season. Moreover, this campaign confirms the difficulty of regulating the species in a clay soil. Finally, as already stated in 2013, it is necessary to set up a local committee dealing specifically with invasive alien species in order to prioritize and coordinate actions.