Biotic indices, which reflect the quality of the environment, are widely used in the marine realm. Sometimes, key species or ecosystem engineers are selected for this purpose. This is the case of the Mediterranean seagrass Posidonia oceanica, widely used as a biological quality element in the context of the European Union Water Framework Directive (WFD). The good quality of a water body and the apparent health of a species, whether or not an ecosystem engineer such as P. oceanica, is not always indicative of the good structure and functioning of the whole ecosystem. A key point of the recent Marine Strategy Framework Directive (MSFD) is the ecosystem-based approach. Here, on the basis of a simplified conceptual model of the P. oceanica ecosystem, we have proposed an ecosystem-based index of the quality of its functioning, compliant with the MSFD requirements. This index (EBQI) is based upon a set of representative functional compartments, the weighting of these compartments and the assessment of the quality of each compartment by comparison of a supposed baseline. The index well discriminated 17 sites in the north-western Mediterranean (French Riviera, Provence, Corsica, Catalonia and Balearic Islands) covering a wide range of human pressure levels. The strong points of the EBQI are that it is easy to implement, non-destructive, relatively robust, according to the selection of the compartments and to their weighting, and associated with confidence indices that indicate possible weakness and biases and therefore the need for further field data acquisition.

A new method based on photographic sampling coupled with in situ observations was applied to 53 stations along the French Mediterranean coast, to assess the integrity of coralligenous reefs affected by different levels of anthropogenic pressure. The conservation state of the assemblages characterizing these habitats was then assessed by an index - the INDEX-COR - that integrates three metrics: (i) the sensitivity of the taxa to organic matter and sediment deposition, (ii) the observable taxonomic richness, and (iii) the structural complexity of the assemblages. The sensitivity of INDEX-COR was tested and showed good correlation with the Level of Pressure calculated for each station according to expert judgment and field observations.

The aim of this study was to obtain information allowing an initial assessment of the potential of French Mediterranean artificial reefs (ARs) as a management tool to aid artisanal fishermen. The study focuses on 3 ARs located along the Gulf of Lion coastline in the French Mediterranean Sea. At the end of spring 2012, experimental fishing with trammel nets was conducted at ARs and natural rocky areas (NRs) at various distances from the ARs/NRs (0, 300 and 900 m). The yields of fish and invertebrates were analyzed at the AR sites to identify significant changes along a distance gradient and to determine whether there was a significant difference between ARs and NRs. The AR yields of species preferring rocky substrates were generally higher between 0 and 300 m from the ARs than beyond 300 m, whereas the yields of species preferring sandy substrates or of invertebrates did not differ between 0 and 900 m from the ARs. Furthermore, the AR yields were equal to the NR yields or were between 1.5-and 1.8-fold higher than the NR yields. Overall, this study indicates that success varied by species, fishing locality and distance from the reef. ARs could be a potentially effective tool for enhancing artisanal fishing along the French Mediterranean coasts. However, it would be necessary to establish management measures to avoid overexploitation. For instance, in terms of the configuration of the AR areas in a given locality, a notake area could be established within a radius of 300 m around the ARs. KEY WORDS: Fish assemblage · Soleidae · Trammel net · Catches · Gulf of LionResale or republication not permitted without written consent of the publisher Aquat Biol 20: 255-272, 2014 French Mediterranean coastal fishing fleet (1545 vessels) in 2010. However, French Mediterranean artisanal fishing has been declining since the end of the 1980s. Between 1986 and, the number of vessels in the artisanal fleet decreased by 50% (Guillou & Crespi 1999) and fell a further 8% between (Guillou & Crespi 1999, IFREMER 2012.This decline in France and in other Mediterranean countries is a notable consequence of increased fishing effort in terms of the engine power and increased capacity of fishing equipment for both artisanal and industrial fisheries. This increased effort has caused the overexploitation of stocks of target species (Pinnegar & Polunin 2004). Furthermore, other anthropogenic pressures, such as sewage pollution, littoral construction and tourism, have also degraded littoral ecosystems (Gómez et al. 2006).Governments emphasize the preservation of artisanal fishing because of its sustainability, due to its use of fishing techniques that are selective in terms of target species and capture size (Forcada et al. 2010). Furthermore, artisanal fishing causes less damage to the seabed and consumes less fuel than industrial or semi-industrial fishing (Forcada et al. 2010). In this context, local authorities have deployed artificial reefs (ARs) along the French Mediterranean coast since the 1980s, notably along the LanguedocRo...

No abstract

Artificial reefs geographical location matters more than shape, age and depth for sessile invertebrate colonization in the Gulf of Lion (NorthWestern Mediterranean Sea), Peer Community Journal, 2: e24.