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Recreational harvesting of the wedge clam (Donax trunculus) in southern Portuga...

This 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 ...

Portuguese social solidarity cooperatives between recovery and resilience in th...

Covid-19 posed several challenges to all organisations in general and to social solidarity cooperatives in particular. However, the challenges faced by these cooperatives have unique features arising from their special characteristics compared to other types of cooperatives. Therefore it is vital to study these challenges and the impacts of covid-19. This study has as main goal to understand those challenges an...

Portuguese social solidarity cooperatives between recovery and resilience in th...

Covid-19 posed several challenges to all organisations in general and to social solidarity cooperatives in particular. However, the challenges faced by these cooperatives have unique features arising from their special characteristics compared to other types of cooperatives. Therefore it is vital to study these challenges and the impacts of covid-19. This study has as main goal to understand those challenges an...

Occurrence, infestation rate, and spatiotemporal distribution of the African pe...

The present study aimed to analyze the occurrence and prevalence, infestation rate and intensity, host-guest colonization pattern, morphometric relationships, and spatiotemporal distribution of the African pea crab (Afropinnotheres monodi) inhabiting the shell of Mediterranean mussels (Mytilus galloprovincialis) from the Algarve coast and Ria Formosa lagoon (southern Portugal). Sampling campaigns were performed...

Reproductive cycle of the golden carpet shell (Polititapes aureus) in the Ria F...

The present study described the gametogenesis and assessed the pattern of energy storage throughout the reproductive cycle of the golden carpet shell (Polititapes aureus) from the Ria Formosa lagoon (southern Portugal). Monthly sampling was performed for two years (March 2016–February 2018) and the study was based on gonad histology, complemented by the estimation of the mean gonadal index, body condition index...

Morphometric relationships, relative growth and roe yield of the sea urchin (Pa...

Sea urchin (Paracentrotus lividus) populations from the northwestern (Carreco) and southwestern (Aljezur) coasts of Portugal were surveyed to analyse and compare their morphometric relationships, relative growth (isometry vs. allometry) and roe yield. Specimens were hand-collected from intertidal rock pools and sampled monthly during two consecutive years (November 2010-November 2012). Overall, 1220 P. lividus ...

Hand dredging for the wedge clam (Donax trunculus) in the Algarve coast (southe...

This study aimed to characterize the catches, quantify fishing yield, bycatch and discards, and also estimate damage and mortality rates using hand dredges with two different mesh sizes (20 and 25 mm) for harvesting the wedge clam (Donax trunculus). A total of 160 tows were performed in Lota Beach and Armona Island in the Algarve coast (southern Portugal). Overall, were caught 12,319 individuals (3985 in Lota B...

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Shell morphology, morphometric relationships and relative growth of three topsh...

This study analysed the shell morphology, morphometric relationships and relative growth in three topshell species (Phorcus lineatus, Phorcus sauciatus and Steromphala umbilicalis) collected in the Algarve coast (southern Portugal). A total of 1382 individuals were sampled (465 P. lineatus, 447 P. sauciatus and 470 S. umbilicalis) and all species comprised individuals with broad size and weight ranges. Morphome...

Singularity subtraction for nonlinear weakly singular integral equations of the...

The singularity subtraction technique for computing an approximate solution of a linear weakly singular Fredholm integral equation of the second kind is generalized to the case of a nonlinear integral equation of the same kind. Convergence of the sequence of approximate solutions to the exact one is proved under mild standard hypotheses on the nonlinear factor, and on the sequence of quadrature rules used to bu...