Marisa Isabel Batista

Over one-third of all elasmobranch species are at risk of extinction worldwide. This study aims to contribute to their conservation worldwide through a case study that combines georeferenced data on species presence and abundance with spatial distribution of human activities, through a Spatial Conflict Risk Index (SCRI). The SCRI pinpoints possible risk areas obtained from the spatial overlap of elasmobranch species abundance and distribution with impacting human activities. Data on species presence and abundance around a Marine Protected Area, the Berlengas Natural Reserve (Portugal) were obtained through four non-invasive methods: Baited Remote Underwater Videos (BRUV), Local Ecological Knowledge (LEK), scientific observers onboard longline commercial fishing vessels and citizen science and social media reports. Human activities were mapped based on LEK. Qualitative abundance and distribution data was obtained for 22 species. SCRI highlighted some high-risk areas due to overlap of areas of frequent occurrence of elasmobranchs with potential high impact activities (e.g. longline fishery). This study highlighted the potential of multi-method approaches to estimate the distribution of rare, highly mobile species in data-limited contexts, and assess their exposure to human activities. The SCRI is a useful tool to support the implementation of effective conservation regulations.

Estuaries are threatened by intense and continuously increasing human activities. Here we estimated the sensitivity of fish assemblages in a set of estuaries distributed worldwide (based on species vulnerability and resilience), and the exposure to cumulative stressors and coverage by protected areas in and around those estuaries (from marine, estuarine and freshwater ecosystems, due to their connectivity). Vulnerability and resilience of estuarine fish assemblages were not evenly distributed globally and were driven by environmental features. Exposure to pressures and extent of protection were also not evenly distributed worldwide. Assemblages with more vulnerable and less resilient species were associated with estuaries in higher latitudes (in particular Europe), and with higher connectivity with the marine ecosystem, moreover such estuaries were generally under high intensity of pressures but with no concomitant increase in protection. Current conservation schemes pay little attention to species traits, despite their role in maintaining ecosystem functioning and stability. Results emphasize that conservation is weakly related with the global distribution of sensitive fish species in sampled estuaries, and this shortcoming is aggravated by their association with highly pressured locations, which appeals for changes in the global conservation strategy (namely towards estuaries in temperate regions and highly connected with marine ecosystems).

The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Madeira Island. As a result of their small size, remote location and harsh sea conditions only a few studies have been conducted to describe their marine species diversity. We were able to identify 29 new coastal fish species, an increase of 33% in the ichthyofauna described for these islands (n = 88). There is a prevalence of species with tropical affinities and only 2.3% (n = 2) are endemic to Macaronesia. Considered a stepping-stone colonization vector from the nearest continental shore, as proposed by other authors for this region, the Selvagens Islands host 34.1% of the ichthyofauna described for the much larger Canary Islands (n_species = 258, submerged area n_SelvagensIs. = 2.3%) and 47.3% of the ichthyofauna described for the more distantly located Madeira Island (n_species = 186, submerged area n_SelvagensIs. = 17.9%). Interestingly, 6.8% (n = 6) of the species failed to bridge the gap between the Selvagens Islands and Madeira Island. Data collected so far showed no trend toward an increasing number of species with high dispersal capability. The Selvagens Islands are an example of a high coastal species diversity occurring even in very small areas of the northeastern Atlantic Ocean.