Browsing by Author "Costa, J. L."
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- Allochthonous-derived organic matter subsidizes the food sources of estuarine jellyfishPublication . Morais, Pedro; Dias, Ester; Cruz, Joana; Chainho, P.; Costa, J. L.; Angélico, M. M.; Barbosa, Ana; Teodosio, MariaJellyfish modulate the energy fluxes between compartments of aquatic ecosystems and the period that energy remains within each compartment. However, the contribution of different sources of organic matter (OM) to the production of most estuarine jellyfish species is unknown. Therefore, this study aimed to identify and quantify the putative sources of OM for Blackfordia virginica (Cnidaria, Hydrozoa) Mayer, 1910 in two temperate estuaries, based on the analyses of carbon and nitrogen stable isotope ratios. Zooplankton was the main source of OM assimilated by B. virginica in both Mira and Guadiana estuaries. However, particulate organic matter (POM) also contributed to B. virginica biomass, up to 26 and 37% in Mira and Guadiana estuaries, respectively. The POM pool was apparently comprised by terrestrial derived OM, as based on stable isotope ratios and C:NPOM. Terrestrial-derived OM is an undescribed carbon source for estuarine jellyfish. Our results support a working hypothesis stating that terrestrial-derived OM might support good physiological condition of B. virginica during periods of low metazooplankton abundance, through a detritus based microbial food web transformation. Subsequent studies on trophic pathways ought to evaluate the temporal contribution of autochthonous and allochthonous OM and its consequences, accounting for the connectivity across ecosystems (terrestrial-estuarine-marine) and the interactions within compartments (pelagic-benthic).
- Ecological quality assessment of transitional waters based on fish assemblages in Portuguese estuaries: The Estuarine Fish Assessment Index (EFAI)Publication . Cabral, H. N.; Fonseca, V. F.; Gamito, R.; Gonçalves, C. I.; Costa, J. L.; Erzini, Karim; Gonçalves, Jorge Manuel Santos; Martins, J.; Leite, L.; Andrade, José Pedro; Ramos, S.; Bordalo, A.; Amorim, E.; Neto, J. M.; Marques, J. C.; Rebelo, J. E.; Silva, C.; Castro, N.; Almeida, P. R.; Domingos, I.; Gordo, L. S.; Costa, M. JThe assessment of water quality has changed markedly worldwide over the last years, especially in Europe due to the implementation of the Water Framework Directive. Fish was considered a key-element in this context and several fish-based multi-metric indices have been proposed. In this study, we propose a multi-metric index, the Estuarine Fish Assessment Index (EFAI), developed for Portuguese estuaries, designed for the overall assessment of transitional waters, which could also be applied at the water body level within an estuary. The EFAI integrates seven metrics: species richness, percentage of marine migrants, number of species and abundance of estuarine resident species, number of species and abundance of piscivorous species, status of diadromous species, status of introduced species and status of disturbance sensitive species. Fish sampling surveys were conducted in 2006, 2009 and 2010, using beam trawl, in 13 estuarine systems along the Portuguese coast. Most of the metrics presented a high variability among the transitional systems surveyed. According to the EFAI values, Portuguese estuaries presented a "Good" water quality status (except the Douro in a particular year). The assessments in different years were generally concordant, with a few exceptions. The relationship between the EFAI and the Anthropogenic Pressure Index (API) was not significant, but a negative and significant correlation was registered between the EFAI and the expert judgement pressure index, at both estuary and water body level. The ordination analysis performed to evaluate similarities among North-East Atlantic Geographical Intercalibration Group (NEAGIG) fish-based indices put in evidence four main groups: the French index, since it is substantially different from all the other indices (uses only four metrics based on densities); indices from Ireland, United Kingdom and Spain (Asturias and Cantabria); the Dutch and German indices; and the indices of Belgium. Portugal and Spain (Basque country). The need for detailed studies, including comparative approaches, on several aspects of these assessment tools, especially in what regards their response to anthropogenic pressures was stressed. (C) 2011 Elsevier Ltd. All rights reserved.
- Ecological quality assessment of transitional waters based on fish assemblages in Portuguese estuaries: the Estuarine Fish Assessment Index (EFAI)Publication . Cabral, H. N.; Fonseca, V. F.; Gamito, R.; Gonçalves, C. I.; Costa, J. L.; Erzini, Karim; Gonçalves, J. M. S.; Martins, J.; Leite, L.; Andrade, José Pedro; Ramos, S.; Bordalo, A.; Amorim, E.; Neto, J. M.; Marques, J. C.; Rebelo, J. E.; Silva, C.; Castro, N.; Almeida, P. R.; Domingos, I.; Gordo, L. S.; Costa, M. J.The assessment of water quality has changed markedly worldwide over the last years, especially in Europe due to the implementation of the Water Framework Directive. Fish was considered a key-element in this context and several fish-based multi-metric indices have been proposed. In this study, we propose a multimetric index, the Estuarine Fish Assessment Index (EFAI), developed for Portuguese estuaries, designed for the overall assessment of transitional waters, which could also be applied at the water body level within an estuary. The EFAI integrates seven metrics: species richness, percentage of marine migrants, number of species and abundance of estuarine resident species, number of species and abundance of piscivorous species, status of diadromous species, status of introduced species and status of disturbance sensitive species. Fish sampling surveys were conducted in 2006, 2009 and 2010, using beam trawl, in 13 estuarine systems along the Portuguese coast. Most of the metrics presented a high variability among the transitional systems surveyed. According to the EFAI values, Portuguese estuaries presented a “Good” water quality status (except the Douro in a particular year). The assessments in different years were generally concordant, with a few exceptions. The relationship between the EFAI and the Anthropogenic Pressure Index (API) was not significant, but a negative and significant correlation was registered between the EFAI and the expert judgement pressure index, at both estuary and water body level. The ordination analysis performed to evaluate similarities among North-East Atlantic Geographical Intercalibration Group (NEAGIG) fish-based indices put in evidence four main groups: the French index, since it is substantially different from all the other indices (uses only four metrics based on densities); indices from Ireland, United Kingdom and Spain (Astúrias and Cantábria); the Dutch and German indices; and the indices of Belgium, Portugal and Spain (Basque country). The need for detailed studies, including comparative approaches, on several aspects of these assessment tools, especially in what regards their response to anthropogenic pressures was stressed.
- Inter-annual variations of macrobenthic communities over three decades in a land-locked coastal lagoon (Santo André, SW Portugal)Publication . Correia, M. J.; Costa, J. L.; Chainho, P.; Félix, P. M.; Chaves, M. L.; Medeiros, J. P.; Silva, G.; Azeda, C.; Tavares, P.; Costa, A.; Costa, A. M.; Bernardo, J.; Cabral, H. N.; Costa, M. J.; Cancela, M. LeonorSanto Andre is an enclosed brackish water coastal lagoon with temporary connections to the sea by a man-made channel. The exchange and mixture of saltwater and freshwater is irregular and the lagoon may show daily and seasonal fluctuations, but also long-term variation. Different benthic communities may be present along the annual cycle according to the magnitude of episodic freshwater and sea water inputs. In the last 30 years the communication with the sea has followed different regimes from year to year and, as a consequence, macrobenthic communities, assessed several times during the period before the opening to the sea, shifted from freshwater to marine affinities. Major differences were found between 1979 and 2010, with a preponderance of species with marine affinity, and the 1980s in which the organisms with freshwater affinity prevailed. Benthic communities are frequently used to assess aquatic environmental condition. Metrics used in the indices currently under discussion to assess ecological status of aquatic ecosystems within the scope of European Water Framework Directive were applied to Santo Andre data and the applicability of these metrics to assess quality in this coastal land-locked lagoon was discussed. (C) 2012 Elsevier Ltd. All rights reserved.
- 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.