83 documents found, page 1 of 9
Comparative study of Ruditapes philippinarum and Ruditapes decussatus in Ria de...
Manuel da Silva Rodrigues Maia, Francisco; Gaspar, Miguel; Barroso, Carlos M.Research on the biological traits of commercial bivalves is essential for developing effective management strategies and ensuring their sustainable exploitation. This study offers a comparative analysis of the invasive Manila clam R. philippinarum and the native grooved carpet clam R. decussatus in the Ria de Aveiro, Portugal, focusing on shell morphometry, growth, reproductive cycle, condition index, and lengt...
Designing a coastal monitoring marine biodiversity survey, using trammel nets a...
Rufino, Marta M.; Maia, Catarina; Dinis, David; Farias, Inês; Moura, Teresa; Gomes, Pedro; Quaresma, Ivania; Martins, Rogélia; Figueiredo, IvoneAlthough coastal areas are of great importance, they often lack long term monitoring surveys, which are essential for effective management, fisheries sustainability, and marine spatial planning. To address this, we conducted two experimental surveys aimed at assessing communities and their biodiversity, with the objective of designing a monitoring program for marine coastal biodiversity, based on gear type, dep...
Growth, reproduction, and size at first maturity of the peppery furrow shell Sc...
Maia, Francisco; Gaspar, Miguel; Barroso, Carlos M.The peppery furrow shell Scrobicularia plana is a commercial valuable bivalve in the east Atlantic and Mediterranean Sea. To ensure the sustainability of this resource and implement efficient management strategies, it is essential to understand the life history traits of the species, such as growth, reproduction, and size at first maturity. These features were investigated in the southern range of the species' ...
Ocean acidification will not affect the shell strength of juveniles of the comm...
SORDO, LAURA; Esteves, Eduardo; Valente, Joana F.A.; Duarte, Catarina; Alves, Nuno; Baptista, Teresa; Gaspar, Miguel; Anibal, JaimeOcean acidification (OA) is expected to decrease the strength of bivalves' shells, especially during the early stages of development, with negative consequences to the resilience of natural populations and the economy. The objectives of the present study were to assess the long-term effect of increasing pCO(2) after 217 days of exposure under controlled conditions of pH of similar to 8.2, 8.0, and 7.7 on the st...
Alluvial Sn and W minerals mapping for mineral resources exploration and resear...
Salgueiro, Rute; Grácio, Nuno; Gaspar, Miguel; de Oliveira, Daniel Pipa SoaresSUMÁRIO: Com base em amostras aluvionares em arquivo no LNEG, foi possível conceber mapas de concentração de grãos de cassiterite, volframite e scheelite, para a região mineira de Segura (Castelo Branco) enquadrada na Faixa metalogenética estanho-tungstanífera de Góis-Segura. O padrão de distribuição da concentração de grãos destes minerais de minério de Sn e W, materializa-se em halos concêntricos distintos, e...
Estimating fishing effort in small-scale fisheries using high-resolution spatio...
Rufino, Marta M.; Mendo, Tania; Samarão, João; Gaspar, MiguelSmall-scale fisheries (SSF, boats < 12 m) represent 90% of this sector at a worldwide scale and 84% of the EU fleet. Mapping the areas and intensity where the fishing operations occur is essential for spatial planning, safety, fisheries sustainability and biodiversity conservation. The EU is currently regulating position tracking of SSF fishing vessels requiring precision resolved geo-positional data (sec to mi...
Recreational harvesting of the wedge clam (Donax trunculus) in southern Portuga...
Sordo, Laura; Vasconcelos, Paulo; Piló, David; Carvalho, André N.; Pereira, Fábio; Gaspar, MiguelThis study was the first attempt to characterize the recreational harvesting of the wedge clam (Donax trunculus). For this purpose, 403 face-to-face interviews were performed in the summers of 2018 and 2019 in southern Portugal. The majority of the harvesters frequented the selected beaches during holidays and collected wedge clams as a hobby for an appetizer. The respondents reported an inter-annual variation ...
Trace Element Geochemistry of Alluvial TiO2 Polymorphs as a Proxy for Sn and W ...
Gaspar, Miguel; Grácio, Nuno; Salgueiro, Rute; Costa, MafaldaThe Segura mining field, the easternmost segment of the Góis–Panasqueira–Segura tin– tungsten metallogenic belt (north–central Portugal), includes Sn-W quartz veins and Li-Sn aplitepegmatites, which are believed to be genetically related to Variscan Granites. Sediment geochemistry indicates granite-related Ti-enrichments, locally disturbed by mineralization, suggesting magmatic and metamorphic/metasomatic titan...
Trace Element Geochemistry of Alluvial TiO2 Polymorphs as a Proxy for Sn and W ...
Gaspar, Miguel; Grácio, Nuno; Salgueiro, Rute; Costa, MafaldaABSTRACT: The Segura mining field, the easternmost segment of the Gois-Panasqueira-Segura tin-tungsten metallogenic belt (north-central Portugal), includes Sn-W quartz veins and Li-Sn aplite-pegmatites, which are believed to be genetically related to Variscan Granites. Sediment geochemistry indicates granite-related Ti-enrichments, locally disturbed by mineralization, suggesting magmatic and metamorphic/metasom...
Climatology and nutrient fluxes in the Tagus estuary: A coupled model application
de Pablo, Hilda; Sobrinho, João; Nunes, Susana; Correia, Alexandre; Neves, Ramiro; Gaspar, MiguelRivers are responsible for the main transport of nutrients from land to estuaries and coastal areas. Understanding the fate of these anthropogenic inputs and their impacts on estuaries and adjacent marine ecosystems is essential for the protection of coastal waters. Here, the 3D MOHID hydrodynamic model coupled with a biogeochemical model was used to determine seasonal nutrient fluxes between areas of the Tagus...