Repository logo
 

Search Results

Now showing 1 - 10 of 73
  • Catches in ghost-fishing octopus and fish traps in the northeastern Atlantic Ocean (Algarve, Portugal)
    Publication . Erzini, Karim; Bentes, L.; Coelho, Rui; Lino, P. G.; Monteiro, P.; Ribeiro, J.; Gonçalves, J. M. S.
    Ghost fishing is the term used to describe the continued capture of fish and other living organisms after a fisherman has lost all control over the gear. Traps may be lost for a variety of reasons including theft, vandalism, abandonment, interactions with other gear, fouling on the bottom (i.e., traps and ropes are caught on rocky substrate), bad weather, and human error (Laist, 1995). Annual trap loss can be as high as 20% to 50% of fished traps in some fisheries (Al-Masroori et al., 2004). Because lost traps can continue to fish for long periods, albeit with decreasing efficiency over time (e.g., Smolowitz, 1978; Breen, 1987, 1990; Guillory, 1993), ghost fishing is a concern in fisheries worldwide.
  • First record of Ocinebrina nicolai (Mollusca: Gastropoda: Muricidae: Ocenebrinae) in North-Eastern Atlantic waters
    Publication . Afonso, Carlos; Bonomolo, Giuseppe; Monteiro, Pedro; Bentes, Luis; Oliveira, Frederico; Veiga, Pedro; Rangel, Mafalda; Sousa, Inês; Leite, Laura; Gonçalves, J. M. S.
    Ocinebrina nicolai Monterosato, 1884 a marine mollusc belonging to the Muricidae family is reported from Algarve, south coast of Portugal for the first time and is a new record for the biodiversity of the Portuguese malacological fauna and northeastern Atlantic waters. This species with a medium-size shell for the genus (14–16 mm) was initially sampled during a baseline project that studied marine biotopes in the central Algarve region. This short note presents a brief diagnosis of the species, provides local information on geographical distribution, habitat, and compares it with other congeneric species found in Portugal: Ocinebrina aciculata (Lamarck, 1822) and Ocinebrina edwardsii (Payraudeau, 1826).
  • Movements of Sarpa salpa (Linnaeus, 1758) (Sparidae) in a coastal lagoon (Ria Formosa, Portugal)
    Publication . Abecasis, D.; Bentes, L.; Erzini, Karim
    The salema, Sarpa salpa (Linnaeus, 1758), is a sparid with a distribution that includes the eastern Atlantic coast from the Bay of Biscay to South Africa, as well as the Azores, Madeira, Canary and Cape Verde archipelagos. It is also found in groups in the Mediterranean Sea and the Indian Ocean from South Africa to Mozambique, living on sandy and seagrass bottoms ranging from 0 to 70 m depth (Bauchot and Hureau, 1986). The species is a protandrous hermaphrodite where, according to Criscoli et al. (2006), sex change occurs between 24 and 31 cm total length (3–7 years old). While the economic value of S. salpa in fisheries is relatively limited, its ecological importance is well recognized, with several studies on its biology and interactions on seagrass meadows (e.g. Verlaque, 1990; Criscoli et al., 2006). As an herbivore Sarpa salpa has a strong impact with seagrass meadows, being responsible for much of the herbivory (Verlaque, 1990; Cebria´n et al., 1996; Prado et al., 2008), and representing a considerable part of the ichthyofauna in these habitats (Francour, 1997, 2000). Studies on S. salpa diel activity patterns, home range and habitat utilization in the Mediterranean Sea were undertaken by Jadot et al. (2002, 2006). These studies have revealed two behaviours, with some fish being highly sedentary while others use larger areas; great variation in mobility was found, with some fish showing both behaviours. The core areas (95%) range between 1600 and 279 000m2 , with some fish presenting diel movement patterns between day and night areas as well as homing abilities. The Ria Formosa, in the southern part of Portugal, is a shallow coastal lagoon with large meadows of seagrasses (Zostera noltii, Zostera marina and Cymodocea nodosa) where the influence of S. salpa on these communities is still unknown. Previous studies on the ichthyofauna of the Ria Formosa coastal lagoon focused largely on temporal and spatial changes in species composition (Monteiro et al., 1990; Ribeiro et al., 2006, 2008). Up to the present, the acoustic telemetry studies carried out in the Ria Formosa focused on the movements and home range of Sparus aurata (Abecasis and Erzini, 2008) and Diplodus spp. (Abecasis et al., 2009). A preceding tag-recapture study of juveniles of S. salpa (between 8.2 and 16.7 cm total length) provided limited information, with only a few recaptures (Abecasis, 2007). The present study was carried out to determine the movement patterns of S. salpa inside a coastal lagoon (Ria Formosa, south Portugal) in order to provide basic information on their home range and site fidelity.
  • Transboundary dimensions of marine spatial planning: Fostering inter-jurisdictional relations and governance
    Publication . Jay, Stephen; Alves, Fátima L.; O'Mahony, Cathal; Gomez, Maria; Rooney, Aoibheann; Almodovar, Margarida; Gee, Kira; Suárez de Vivero, Juan Luis; Gonçalves, J. M. S.; da Luz Fernandes, Maria; Tello, Olvido; Twomey, Sarah; Prado, Inmaculada; Fonseca, Catarina; Bentes, L.; Henriques, Guida; Campos, Aldino
    There is broad agreement that marine spatial planning (MSP) should incorporate transboundary considerations, reflecting the cross-border nature of marine and coastal ecosystem dynamics and maritime resources and activities. This is recognised in the European Union's recent legislation on MSP, and experience in transboundary approaches is developing through official processes and pilot studies.
  • Marxan as a zoning tool for development and economic purposed areas - Aquaculture Management Areas (AMAs)
    Publication . Sales Henriques, Nuno; Monteiro, Pedro; Bentes, Luis; Oliveira, Frederico; Afonso, Carlos; Gonçalves, Jorge Manuel Santos
    The increased number of human activities within the marine environment and the demand for maritime space has increased to a point where in some parts of the globe the demand for maritime space has exceeded the available area. The overlapping objectives and activities have caused severe conflicts among users and with the natural marine environment itself. For that reason, holistic strategies such as Ecosystem Based Management (EBM) and Maritime Spatial Planning (MSP) have been evolved and developed to sustainably manage the marine environment, avoiding conflicts and creating synergies. Spatial analysis tools like Marxan have been used for several years as decision support tools mostly for conservation plans, such as design and establishment of protected areas. In this study we approach the potential of this tool with a different purpose in mind: instead of using the available information of the region for the development of a conservation plan, we used this tool and the available information to select areas to establish Aquaculture Management Areas (AMAs). We also intended to analyse how the existing features of the region would affect the final result of a spatial plan aimed to establish areas for economic and development purposes. We conclude that the use of Marxan can be advantageous to support the planning and development of coastal regions, not only in a conservationist point of view (as it has been mostly used), but also into a developing and economic driven approach. This tool can be particularly useful in regions or situations where there is a large number of stakeholders, ecological and geographical features that could potentially conflict with the establishment, the management and the success of the proposed management areas. (C) 2017 Elsevier Ltd. All rights reserved.
  • Length-weight relationships of six syngnathid species from Ria Formosa, SW Iberian coast
    Publication . Vieira, RP; Monteiro, P.; Ribeiro, J.; Bentes, L.; Oliveira, F.; Erzini, Karim; Gonçalves, J. M. S.
    In this study, the length-weight (LWR) parameters were estimated for six syngnathid species, including 2 seahorses and 4 pipefishes, from Ria Formosa, a temperate lagoon from the south coast of Portugal. A total of 5070 fishes were used to determine the LWR. The estimated b value ranged from 2.95 (Nerophis ophidion) to 3.36 (Syngnathus abaster). To the authors' best knowledge, LWR parameters were estimated for the first time for Nerophis ophidion and Syngnathus typhle for the Atlantic waters. Data here present are essential for management and conservation of these flagship species.
  • Identifying persistent hot spot areas of undersized fish and crustaceans in southern european waters: implication for fishery management under the discard ban regulation
    Publication . Milisenda, Giacomo; Garofalo, Germana; Fiorentino, Fabio; Colloca, Francesco; Maynou, Francesc; Ligas, Alessandro; Musumeci, Claudia; Bentes, Luis; Gonçalves, Jorge Manuel Santos; Erzini, Karim; Russo, Tommaso; D’Andrea, Lorenzo; Vitale, Sergio
    The recent establishment of the "landing obligation" under the reformed EU Common Fishery Policy has the twofold objective of reducing the excessive practice of discarding unwanted catch at sea and encouraging more selective and sustainable fisheries. Within this context, the awareness of the spatial distribution of potential unwanted catches is important for devising management measures aimed to decrease discards. This study analyzed the distribution of Hot Spot density areas of demersal fish and crustaceans below the Minimum Conservation Reference Size (MCRS) in four different southern European seas: continental Portuguese coast, Catalan Sea, South of Sicily, Liguria and northern Tyrrhenian Seas using both bottom trawl survey data and information on the spatial distribution of commercial fisheries. Critical areas for discarding were identified as zones where the highest densities of individuals below MCRS were consistently recorded throughout a series of years. Results clearly showed a patchy distribution of undersized individuals in each investigated area, highlighting the overlap between high density patches of both discards and fishing effort. The present findings provide a relevant knowledge for supporting the application of spatial-based management actions, such as the designation of Fisheries Restricted Areas (FRAs), in order to minimize the by-catch of undersized specimens and improve the sustainability of demersal fisheries
  • Use of different intertidal habitats by faunal communities in a temperate coastal lagoon
    Publication . Almeida, C.; Coelho, R.; Silva, M.; Bentes, L.; Monteiro, P.; Ribeiro, J.; Erzini, Karim; Gonçalves, J. M. S.
    The faunal communities of four intertidal habitats namely sand, mud, seagrass (Zostera noltii) and seagrass patches (mixSM) of a temperate coastal lagoon, Ria Formosa (southern Portugal), were sampled. A total of 47 species were taken in 428 bottomless drop sampler samples, with the highest number of species and the more commonly occurring species belonging to the Mollusca phylum. The dominance of these gastropod species underlines the importance of the grazing food chain in these habitats. Bittium reticulatum was the most abundant species, being especially abundant in the seagrass habitat. The most frequent and highest biomass species in the community was Carcinus maenas, a predator that makes use of the available resources and that is adapted to the highly variable intertidal environment. Pomatoschistus microps was the most abundant fish species, with highest densities in the mud habitat, which demonstrates an ability to occupy a low depth area. The seagrass; habitat had the highest diversity, abundance and biomass, followed by the mixSM habitat and was different from all the others. Assemblages were highly influenced by the presence of vegetation, providing forage and refuge from predation. A well defined summer group was identified in all habitats. These results highlight the importance of seagrass beds and the idea that their decrease implies the decrease of lagoon production through the impoverishment of the trophic structure of the lagoon. (C) 2008 Elsevier Ltd. All rights reserved.
  • Identifying habitats of conservation priority in the São Vicente submarine Canyon in Southwestern Portugal
    Publication . Nestorowicz, Iga-Maria; Oliveira, Frederico; Monteiro, Pedro; Bentes, Luis; Sales Henriques, Nuno; Aguilar, Ricardo; Horta E Costa, Barbara; Gonçalves, Jorge Manuel Santos
    Identifying vulnerable marine habitats is fundamental to promote evidence-based management and a sustainable use of our oceans. Although progress in the mapping of marine benthic habitats has been made, complex ecosystems such as submarine canyons remain largely unexplored, hampering evidence-based management from taking place in these ubiquitous features worldwide. Data from a remotely operated vehicle (ROV) survey in the upper São Vicente Submarine Canyon in southwestern Portugal from 2011, was analysed to carry out a comprehensive assessment of megabenthic habitats, particularly those of conservation concern occuring between 90 and 560 m. Underwater videos from three exploratory dives, covering a total of 8.8 kilometers, were analyzed through multivariate and visual assessments, and the identified habitats were assessed against a set of criteria derived from current definitions of priority habitats. Thirteen potential priority habitats were characterized, out of which four distinct “coral gardens” and one “deep-sea sponge aggregation” are aligned with OSPAR definitions of priority habitats, and one corresponds to the habitat of a strictly protected sea urchin listed in the Habitats Directive. Three circalittoral sponge aggregations were also suggested based on the abundance of indicator species. The specific composition and diversity of priority habitats as described here, has not yet been described in any other canyon in the NE Atlantic region. Depth was revealed to be particularly important for the distribution of habitats, followed by relief and substratum. The approach presented in this study contributes to improve the understanding about submarine canyons, which is paramount to implement knowledge-based protection measures. Furthermore, it can be used to support future mapping efforts of deep-sea environments such as submarine canyons.
  • Movements of hatchery-reared dusky groupers released in a northeast atlantic coastal marine protected area
    Publication . 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 Ruivo
    No-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.