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International audienceArtificial reefs have been deployed in France since 1968 with the principal objective of enhancing success and continuity of artisanal fishing. Over 50 % of the volume of reef material has been deployed since 2000. Because of significant expansionof reef construction and availability of new research results concerning their performance since the late 1990s, we examined status and trends of French artificial reefs. Since the review of Barnabe´ et al. (Artificial reefs in European seas, 2000), 35 reports have been published and are analyzed here. Fish assemblages on artificial reefs have been the focus of ecological research, with emphasis on species richness and abundance. Fish production has been associated with the age of artificial reefs and the reef’s structural complexity. The perception of stakeholders toward artificial reefs is a notable area of investigation. Economic studies are absent. Other developments in French artificial reefs over the last 10–15 years include the discontinued use of waste materials in reef construction, more directed design of reef structure, and the inclusion of additional objectives concerning biodiversity and recreation. Recommendations here include development of long-term ecological studies of artificial reefs and the evaluation of fishery production, including issues such as trophic dynamics, ecological connectivity of habitats, and socio-economic studies

For the first time three specimens belonging to the species Pomadasys incisus (Bowdich, 1825), the bastard grunt, were caught in the French Ligurian Sea. This subtropical species, which naturally entered the Mediterranean Sea through the Straits of Gibraltar in the first half of the nineteenth century, and is currently colonizing the whole Mediterranean coast except the Adriatic Sea, was until now unknown for this region. We reviewed its distribution after a compilation of the available literature, and tried to explain the spreading and the establishment of the bastard grunt as a Mediterranean species in light of the prevailing Mediterranean currents and the possible climate changes.

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Engaging non-scientists to survey ecosystems, a process known as citizen science has been adopted worldwide. For the first time, this was applied to monitor fish assemblages in the Kas Peninsula, Turkey, an area known for its important Lessepsian fish populations. For 3 years (2004, 2007 and 2010), fish assemblages were surveyed using underwater visual census by transect method. A total of 29 species was observed, seven of which were Lessepsian species. Results show a significant increase in the Lessepsian species over the study period. In 2004, they represented 34% of the total abundance, increasing to >61% in 2010. Differences were observed in the progression of populations between two invasive herbivores, Siganus rivulatus and Siganus luridus (Siganidae), and two native herbivores, Sparisoma cretense (Scaridae) and Sarpa salpa (Sparidae). The siganids were recorded each year in all sites, whereas S. cretense was regularly observed in fewer numbers, while S. salpa was rarely censused. Abundance of Siganus spp. increased threefold in 6 years while abundances of S. cretense and S. salpa remained stable. S. rivulatus was the most abundant among the four species. Its competitive superiority may be due to its greater adaptability to fluctuating environmental conditions and biological traits, e.g. rapid growth, earlier sexual maturity, high fecundity. Because siganids are herbivorous, their presence can strongly impact algal ecosystems. It is then important to follow their spreading at a large scale, but this can be challenging due to the limited number of scientists. Adopting citizen science can thus be a useful strategy to monitor the spread of invasive species in the Mediterranean.