Percorrer por autor "Silva, Ana Filipa"
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- Fully protected marine areas linked to reduced home ranges of fishesPublication . Ohayon, Sarah; Abecasis, David; Almeida, Pedro R.; Alós, Josep; Aspillaga, Eneko; Belo, Ana Filipa; Costa, José Lino; Di Franco, Antonio; Di Lorenzo, Manfredi; Ferguson, Adrian; Guidetti, Paolo; Kraft, Sebastian; La Mesa, Gabriele; Olsen, Esben Moland; Parsons, Darren; Pickholtz, Renanel; Quintella, Bernardo R.; Silva, Ana Filipa; Taylor, Brett M.; Villegas‐Ríos, David; Belmaker, JonathanHome range size is a fundamental trait that can affect the probability of fish being harvested and, at the same time, may be affected by fishing. The relationship between home range size and fishing will impact the effectiveness of fully protected areas (FPAs), as it will influence the number of fish moving into fished areas, affecting both spillover and edge effects. One hypothesis is that individuals within FPAs will present reduced home range size relative to individuals in fished areas. This pattern can be driven by demographic selection (e.g. fishing of individuals with large home ranges leaving the FPAs), improved habitat requiring less foraging movements, or behavioural changes associated with reduced fishing threats. To test the relationship between home range size and protection, we compiled 1143 individual-level home range sizes based on acoustic tracking, covering 17 species from 11 FPAs in 7 countries, with information on distance from FPA borders. A dichotomic analysis (in/out of FPAs) did not support a significant change in the home range size between FPAs and fished areas. However, continuous analysis across the FPA borders demonstrated reduced home range size within the FPAs. We did not find an effect of FPA age or size on this pattern. While we cannot pinpoint the underlying mechanism for the pattern revealed, we suggest behavioural changes as the main driver for reduced home range within FPAs. This mechanism will lead to more resident populations within FPAs, reducing fishing mortality within FPAs yet limiting spillover benefits to adjacent fisheries.
- Movements of hatchery-reared dusky groupers released in a northeast atlantic coastal marine protected areaPublication . Silva, Ana Filipa; Horta E Costa, Barbara; Costa, José Lino; Pereira, Esmeralda; Marques, João Pedro; Castro, João J.; Lino, Pedro G.; Candeias-Mendes, Ana; Pousão-Ferreira, Pedro; Sousa, Inês; Bentes, Luis; Gonçalves, Jorge Manuel Santos; de Almeida, Pedro Raposo; Quintella, Bernardo RuivoNo-take areas are key instruments to promote the effectiveness of Marine Protected Areas (MPAs), particularly concerning the protection of endangered species such as the dusky grouper (Epinephelus marginatus). However, despite the establishment of no-take areas and the prohibition of catching this species in a southwestern Portuguese MPA (SACVMP—‘Sudoeste Alentejano’ and ‘Costa Vicentina’ Marine Park) since 2011, there is still no evidence of population recovery. By using acoustic biotelemetry, this work aimed to evaluate the feasibility of restocking hatchery-reared adult dusky groupers in two no-take areas within the SACVMP. In 2019 and 2021, thirty groupers were tagged with acoustic transmitters and the site attachment and movements of the groupers were assessed in the releasing sites (no-take areas). None of the tagged fish settled down in either of the areas, leaving the no-take areas mainly at dusk and night. Some individuals displayed extended movements of more than a hundred kilometers along the Portuguese coast which was rarely reported for this species. At least in some coastal stretches, those movements were performed close to the shore, which may evidence the importance of coastal MPAs to protect and promote the connectivity of species more associated with rocky reef habitats. Following studies should focus on the conditions that promote site attachment and fidelity by hatchery-reared dusky groupers so that future large-scale restocking programs can be successful in MPAs with appropriate habitats.