Anthropogenic impacts on Posidonia oceanica meadows have led to a decline of this ecosystem throughout the Mediterranean. Transplantations have often been prescribed as a compensation measure to mitigate the impacts caused by coastal maritime works. Here a Q methodology approach was used to investigate the stakeholders’ attitudes in four case studies of P. oceanica transplants realized in Italian waters. Twenty-two respondents were asked to score 37 statements, and the resultant Q-sorting was analyzed via an inverse PCA using the KADE software. Four discourses, corresponding to the significant axes in the factorial analysis were identified: science and conservation (F1), oriented at a rigorous scientific approach; engineering and industry (F2), oriented at the economic development; environmentalism and participation (F3), oriented at the conservation of seagrass meadows; and transplantation-oriented (F4), oriented at the realization of transplants as compensation measures. The main conflicts and agreements between discourses are assessed and discussed, based on the analysis of the distinguishing statements that contributed to consensus or disagreement among discourses. The benefits of the Q methodology in the identification and mediation of conflicts in the four case studies are discussed, and its potential as a powerful aid in the development of a good environmental governance is acknowledged.

This paper reports the results of a 15-year trawl ban imposed in 1990 in the Gulf of Castellammare (GCAST: NW Sicily, central Mediterranean Sea) and its effects on the biomass and size structure of demersal finfish and shellfish and on the proportion of different commercial categories of fish. Data were collected by experimental trawl surveys conducted in the GCAST and in two trawled areas before and after 1990. The biomass of the total assemblage and of a number of selected species was significantly higher in the GCAST after the ban. Highly commercial species had the largest increase in the same gulf after the ban, particularly at the depths used by artisanal fishermen. The results from size-based indicators were not as clear-cut as those from biomass though. Although the length frequency distributions obtained in the GCAST were significantly different from the other gulfs, in several cases, the values of the size indicators were higher in the trawled gulfs. Our results suggest that, at the temporal and spatial scale adopted, trawl bans may drive full biomass recovery but only partial size structure recovery of the fish populations subject to trawl exclusion, at least in the Mediterranean. The trawl ban in the Gulf of Castellammare provides an example of an effective ecosystem-based fisheries management tool that offers the potential for fish stock rebuilding and for the economic sustainability of artisanal, small-scale fisheries.