Browsing by Author "Cabral, H."
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- Genetic evidence fails to discriminate between Macroramphosus gracilis Lowe 1839 and Macroramphosus scolopax Linnaeus 1758 in Portuguese watersPublication . Robalo, J. I.; Sousa-Santos, C.; Cabral, H.; Castilho, Rita; Almada, V. C.Fish belonging to the genus Macroramphosus are distributed throughout the Atlantic, Indian and PaciWc oceans. Some authors consider this genus monotypic, Macroramphosus scolopax being the only valid species. Other authors consider (based on several morphological and ecological characters) that another species (Macroramphosus gracilis) exists and occurs frequently in sympatry with the Wrst one. Intermediate forms are also reported in literature. In this paper, using the mitochondrial control region and the nuclear Wrst S7 intron markers, we failed to Wnd genetic diVerences between individuals considered to belong to both species as well as the intermediate forms. Our results suggest that in the northeastern Atlantic, Macroramphosus is represented by a single species, M. scolopax, with diVerent morphotypes interbreeding in the sampling areas.
- Measuring underwater noise with high endurance surface and underwater autonomous vehiclesPublication . Silva, A.; Matos, A.; Soares, C.; Alves, J. C.; Valente, J.; Zabel, F.; Cabral, H.; Abreu, N.; Cruz, N.; Almeida, R.; Ferreira, R. N.; Ijaz, S.; Lobo, V.This paper describes the results of AcousticRobot'13 - a noise measurement campaign that took place off the Portuguese Coast in May 2013, using two high endurance autonomous vehicles capable of silent operation (an underwater glider and an autonmomous sailing vessel) equipped with hydrophones, and a moored hydrophone that served as reference. We show that the autonomous vehicles used can provide useful measurements of underwater noise, and describe the main advantages and shortcomings that became evident during the campaign.
- Phylogenetic relationships of the North-eastern Atlantic and Mediterranean forms of Atherina (Pisces, Atherinidae)Publication . Francisco, S. M.; Congiu, L.; Stefanni, S.; Castilho, Rita; Brito, A. B.; Ivanova, P. P.; Levy, A.; Cabral, H.; Kilias, G.; Doadrio, I.; Almada, V. C.The genus Atherina (Sand-smelts) is distributed in the Eastern Atlantic Ocean and Mediterranean Sea, extending south along the African coast into the Indian Ocean (Quignard and Pras, 1986). It is a genus of small inshore fishes with many populations living in brackish and freshwater. The taxonomy of the genus has been troublesome due to the intraspecific variability of some of its species, the overlap of characters among many of them and because many nominal species were apparently described based on individuals originating from different localities.
- Robustness of the Estuarine Fish Assessment Index (EFAI) regarding water body definition criteriaPublication . Gonçalves, C. I.; Pasquaud, S.; Gamito, R.; Fonseca, V. F.; Costa, J. L.; Erzini, Karim; Gonçalves, Jorge Manuel Santos; Martins, J.; Leite, L.; Castro, N.; Andrade, José Pedro; Ramos, S.; Bordalo, A.; Amorim, E.; Neto, J. M.; Marques, J. C.; Costa, M. J.; Cabral, H.According to the Water Framework Directive (WFD) transitional waters should be differentiated according to type and, in some cases, divided into different water bodies. This raises a dilemma in trying to define parts of a continuum. In the sequence of WFD several indices have been proposed including the Estuarine Fish Assessment Index, which can be applied taking an estuary as a whole (EFAI - without water bodies division) or divided in water bodies (EFAI(WB)). The purpose of this work is to analyze the robustness of the Estuarine Fish Assessment Index, based on three different ways of dividing Portuguese estuaries into water bodies according to different criteria (criterion 1 - distance to the estuary mouth, criterion 2 - salinity and criterion 3 - morphology, salinity and human dimension as pressure and state). In this study we evaluated at which degree these three criteria could influence the ecological quality ratio (EQR) results, when the index was applied to water body level (EFAI(WB)). Also, for each estuary, the EQR(WB) results for each criterion of EFAI(WB) were combined and weighted according to the water bodies areas (EFAI overall weighted - EFAI(Ow)). Finally, it was compared if the results obtained for each criterion with the EFAI(OW) were similar to the results of the index application taking the estuary as a whole (EFAI without water bodies division). No significant differences were found in both cases, which indicated that this index is a robust method regarding the division of the estuaries in different water bodies, which is an important element of a fish-based multimetric tool for assessing estuarine ecological quality. However, in some cases, different ecological quality statuses were achieved when applying the EFAI(Ow) or the EFAI. This work addressed several aspects regarding the possible division of water bodies at the WFD context. (C) 2012 Elsevier Ltd. All rights reserved.