Percorrer por autor "Garcia-Vazquez, Eva"
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- Environmental DNA as a complementary tool for monitoring fish assemblages in coastal lagoons: Insights for conservationPublication . Fernandez, Sara; Monteiro, Pedro; Garcia-Vazquez, Eva; Gonçalves, Jorge Manuel Santos; Erzini, KarimFor their scarcity, invasive species in early invasion stages and endangered species are often difficult to detect compromising both conservation and ecosystem protection. Here environmental DNA (eDNA) was compared with beach seining for monitoring fish diversity in the protected Natural Park Ria Formosa lagoon (Portugal). Surface water for eDNA extraction was collected before sampling a mean of 1400m2 from ten diverse shallow water habitats with a 25 m beach seine. Fragments of the 12S rRNA and COI mitochondrial genes were PCRamplified and taxonomy was assigned to amplicon sequence variants. Sampling with the beach seine resulted in the identification of 33 species and 4 genera while 28 species were identified based on eDNA, with 18 taxa in common. Greater taxonomic resolution at a species level was possible with eDNA. While the majority of species detected with both methods were of least concern according to IUCN criteria, eDNA detected one invasive (the weakfish Cynoscion regalis with 12S marker) and two critically endangered species (the ray Aetomylaeus bovinus with 12S and the eel Anguilla anguilla with COI marker), none of which were caught by beach seining. C. regalis is a threat in Portuguese waters and should be surveyed in Ria Formosa. The results highlight the usefulness of eDNA as a cost-effective complementary method to traditional monitoring, especially for rare species. Based on these results, we recommend the use of eDNA with multiple markers in surface and bottom water samples in long-term monitoring programmes, to enhance the detection of rare, elusive species in coastal lagoons.
- Potential microplastics impacts on African fishing resourcesPublication . Masiá, Paula; Mateo, Juan L.; Arias, Andrés; Bartolomé, Marlene; Blanco, Carmen; Erzini, Karim; Le Loc'h, François; Mve Beh, Jean Hervé; Power, Deborah; Rodriguez, Noemi; Schaal, Gauthier; Machado-Schiaffino, Gonzalo; Garcia-Vazquez, EvaMicroplastic (MP) pollution is increasing worldwide and affecting aquatic fauna in different ways, which endangers current aquatic resources in a still unknown extent. MP-induced threats to marine fauna are critical for developing countries, where waste treatment may be not optimal and coastal communities rely heavily on marine resources for dietary protein. In this study, we assess the importance of MP pollution for African fishing resources. A new meta-database was created from published studies, containing 156 samples with more than 6200 individuals analysed for microplastic content from African and adjacent waters. A combination of research landscape analysis and rank analysis served to identify main research targets and to determine regional fishing resources especially affected by MP. A network of relevant terms showed fish health as a concern in Mediterranean waters, environmental pollution in freshwater and an emphasis on plastic items in South Africa. MP contents in fishing resources from Nile countries and the Gulf of Guinea, followed by Tunisia, are significantly higher than in other regions. Some of the most exploited species are among the most polluted ones, highlighting the threat of MP pollution in valuable but already compromised African fishing resources. Large geographic gaps with almost absent data about MP in aquatic fauna were revealed, especially in freshwater and in East African coasts. These results emphasize the importance of increasing the coverage of MP pollution in African fishing resources, and improving plastic waste management in the continent.
- Two fish in a pod. Mislabelling on board threatens sustainability in mixed fisheriesPublication . Blanco-Fernandez, Carmen; Erzini, Karim; Rodriguez-Diego, Sara; Alba-Gonzalez, Pablo; Thiam, Ndiaga; Sow, Fambaye Ngom; Diallo, Mamadou; Viðarsson, Jónas R.; Fernández-Vidal, Duarte; Gonçalves, Jorge Manuel Santos; Rangel, Mafalda; Stobberup, Kim; Garcia-Vazquez, Eva; Machado-Schiaffino, GonzaloAccuracy in reporting captures is a key element to achieve fisheries sustainability. However, identification of the catches might be a challenge when two or more species are morphologically similar and caught jointly, like the mixed fisheries of black hakes in East Atlantic African waters. Black hakes (Merluccius senegalensis and M. polli) are tough to differentiate without previous training due to their high morphological resemblance. The two species are managed as a single stock, although the biological differences between them suggest the need of a separate management. In this study, a total of 806 black hakes were visually identified by fishers on deck of fishing vessels operating in Mauritania and Senegal waters, then assigned to a species by sequencing 450bp of the Mitochondrial Control Region. Comparing the results with visual identification we found 31.4% of the total catch were incorrectly labelled on board by the fishermen. The accuracy of the fishers' identification depended on the depth of capture and on fish size, larger individuals caught from deeper waters being more correctly assigned to M. polli. Mislabelling biased to M. polli suggests that M. senegalensis, already catalogued as endangered, is being underreported, which could endanger the conservation of this species and threaten the sustainability of black hake fisheries. Our results highlight the need for separate evaluation of the stocks in mixed fisheries for morphologically similar fish. Thus, monitoring through DNA barcoding in the very first step of the seafood chain surveys would improve accurate species delimitation and reduce its impact on the correct assessment of the stocks.