Among the non-native species found in the Mediterranean, rabbitfish (Siganus rivulatus and S. luridus) are considered to be one of the greatest threats to coastal ecosystems. Originated from the Red Sea, these species, which are exclusively herbivorous, form very large schools and cause overgrazing, especially on the Posidonia meadows and Cystoseira forests. Since their arrival by the Suez Canal, the Siganus had remained confined to the eastern basin of the Mediterranean during more than 50 years. Recently, with the increase of seawater temperature, some Siganus have been observed in the western Mediterranean and these reports worry scientists.

This project aims to model and map the risk of establishment of rabbitfish in the Western Mediterranean and its future expansion during the 21st century. For this purpose, we will develop ecological niche models for both Siganidae species and the autochthonous herbivore (Sarpa salpa) with which they compete. These models will be coupled with IPCC climate models to project climate-induced changes in the geographical distribution of these species up to 2100. A multi-model and multi-scenario approach will be used to quantify uncertainties in projections.