Salt marshes are among the most valuable ecosystems on earth; however, previous research has reported global losses in their extent accompanied by an impairment of their ecological processes. Nonetheless, investigations on salt marsh vegetation ecology are still lacking in many sites, including in Ria de Aveiro. As such, this study aimed to (1) monitor, characterize, and understand the evolution of salt marsh vegetation communities at three different study sites with different environmental conditions and stages of degradation, where we also sought to (2) identify the main delimiting abiotic factors associated with the distribution of the main species. To do so, a multidisciplinary approach that involved the survey of vegetation from permanent transects and the collection of ecological, physicochemical, and hydrodynamic data at sampling points within the monospecific stands of the main species was reported. The results showed that, of the abiotic factors deemed as the main delimiting forces of salt marsh vegetation, the soil elevation and hydroperiod were the most restrictive factors, as they ultimately influenced species composition at the different study sites and explained most of the variation observed between the studied monospecific stands.

Marine Protected Areas (MPAs) are key tools for biodiversity conservation and fisheries management, yet their effectiveness can vary depending on the level of protection. This study compares fish communities and estimated economic values between a fully protected no-take area and a partially protected area allowing recreational fishing and the collection of live bait for commercial tuna fisheries within the Porto Santo Marine Reserve (Madeira Archipelago, Portugal). Underwater visual census data revealed no significant differences in species richness or density between the two MPAs, but fish biomass and associated economic value were significantly higher in the fully protected area. High-value commercial species were more abundant and larger in the no-take zone, resulting in an estimated stock value nearly three times greater than in the partially protected area. These findings highlight how even limited fishing allowances can undermine ecological and economic benefits, underscoring the importance of fully protected MPAs in sustaining marine biodiversity and maximizing fisheries-related ecosystem services.