Percorrer por autor "MENDES, SUSANA"
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- Arsenic accumulation in intertidal macroalgae exposed to sewage dischargesPublication . Cabral-Oliveira, Joana; Coelho, Helena; Pratas, João; Mendes, Susana; Pardal, Miguel A.Arsenic is a widely distributed element in marine ecosystems. The main anthropogenic sources of this contaminant are domestic and industrial wastewaters, and since it can be harmful to humans even at low concentrations, it has been ranked as one of the top hazardous substances. Therefore, the analysis of arsenic is an essential task to assess the potential environmental and human health risk associated with sewage discharges. The accumulation of total arsenic on intertidal rocky shore macroalgae exposed to contaminated sewage discharges was measured in five macroalgae species (Asparagopsis armata, Codium sp., Plocamium cartilagineum, Saccorhiza polyschides and Ulva sp.). Differences in the concentrations of arsenic were examined in the seawater and in the macroalgae species. The results showed significantly higher concentrations of arsenic near the sewage discharges in all the species except S. polyschides. Although the information obtained from total arsenic determination is not enough to assess the toxicological risk in the environment, this paper gives an important contribution on contamination risks and helps in choosing potential good biomonitors.
- CO-tucker: a new method for the simultaneous analysis of a sequence of paired tablesPublication . Mendes, Susana; Fernández-Gómez, M. José; Cotrim Marques, Sónia; Pardal, Miguel Ângelo; Azeiteiro, Ulisses Miranda; Galindo-Villardón, M. PurificaciónRelationships between species and their environment are a key com ponent to understand ecological communities. Usually, this kind of data are repeated over time or space for communities and their envi ronment, which leads to a sequence of pairs of ecological tables, i.e. multi-way matrices. This work proposes a new method which is a combined approach of STATICO and Tucker3 techniques and deals to the problem of describing not only the stable part of the dynamics of structure–function relationships between communities and their environment (in different locations and/or at different times), but also the interactions and changes associated with the ecosystems’ dynamics. At the same time, emphasis is given to the comparison with the STATICO method on the same (real) data set, where advan tages and drawbacks are explored and discussed. Thus, this study produces a general methodological framework and develops a new technique to facilitate the use of these practices by researchers. Fur thermore, from this first approach with estuarine environmental data one of the major advantages of modeling ecological data sets with the CO-TUCKER model is the gain in interpretability.
- Effect of stocking density and different diets on growth of Percula Clownfish, Amphiprion percula (Lacepede, 1802)Publication . Chambel, João; Severiano, Vera; Baptista, Teresa; Mendes, Susana; Pedrosa, RuiThe aim of this study was to evaluate the influence of stocking density (0.5, 1, 2 and 3 fishL−1) and commercial marine fish diets (diet A, B, C and D) over four months on specific growth rate, condition factor, percentage without anomalous pigmentation (partial or total lack of white bands -miss-band) and survival of juvenile Amphiprion percula. Results showed that at 0.5 fishL−1 densities induced the best survival (100%) and also the maximum percentage of fish without miss-band (58.33 +/−4.417%). The maximum SGR was obtained for the 0.5 fishL−1 (0.459 ± 0.023% cm/day). However, the best condition factor (2.53 +/− 0.27) was achieved for 2 fishL−1 densities. There were no significant differences in survival (68.9 to 84.5%), fish without miss-bands (18.03 to 26.92%) and condition factor (1.92 to 2.1) among diets during the experimental period. On the other hand, diet C (with 41% crude protein) supported the best SGR (0.485 ± 0.001% cmday−1). The results suggested that stocking density are critical and more relevant when compared with the different diet tested, namely on specific growth rate, condition factor, the miss-band and survival of juvenile percula clownfish. This study has particular significance with regards to anemonefishes husbandry in terms of survival and production efficiency.
- The efficacy of MS-222 as anaesthetic agent in four freshwater aquarium fish speciesPublication . Chambel, João; Pinho, Rúben; Sousa, Rita; Ferreira, Tânia; Baptista, Teresa; Severiano, Vera; Mendes, Susana; Pedrosa, RuiThe efficacy of anaesthetic tricaine methanesulfonate (MS-222) was evaluated in four freshwater aquarium fish species, Zebrafish (Danio rerio), Guppy (Poecilia reticulata), Discu (Symphysodon discus) and Green swordtail (Xiphophorus helleri). The correct dose of anaesthetic should induce the plane 4 of anaesthesia in less than 180 s, recovery in less than 300 s and must survive when exposed during 30 min to anaesthetic. Fishes were exposed to six concentrations of anaesthetic (75, 100, 125, 150, 200 and 250 mg L-1) and the time of fish reaching plane 4 of anaesthesia, post exposure recovery, and the percentage of survival when fish were subject to 30 min in the anaesthetic were recorded. The optimal doses varied according to the species: D. rerio - 75, 100 and 125 mg L-1, P. reticulata - 125, 150 and 200 mg L-1, S. discus - 75 and 100 mg L-1 and X. helleri - 125 and 150 mg L-1. The induction time generally decreased significantly with increasing concentration of MS-222 for all of the species evaluated. The recovery time had a tendency to increase with the increase of the MS-222 concentration for D. rerio, P. reticulata and S. discus. On the other hand, X. helleri recovery time decreased with the increase of MS-222 concentration. MS-222 proved to be effective in anaesthesia for all the freshwater ornamental species studied. The main results clearly show that the optimal dose to anesthetize is fish species dependent and it is completely wrong to extrapolate optimal anaesthetic concentrations between different species.
- The impact of conspicuous environmental changes on the spatial and temporal dynamics of Acartia tonsa and Acartia clausi: A decadal study in a temperate estuary (Mondego, Portugal)Publication . Marques, Joana C.; Primo, Ana L.; Falcão, Joana; Martinho, Filipe; Mendes, Susana; Azeiteiro, Ulisses M.; Pardal, Miguel A.This chapter aimed to identify the role of natural environmental factors in the distribution of the congeneric species Acartia tonsa and Acartia clausi in the Mondego estuary, central Iberian Peninsula, over the period 2003-2012. A. tonsa was the dominant species during the study period, representing 84% of the total abundance of Acartia. The distribution patterns of Acartia species revealed a spatial segregation along the estuary, with A. tonsa confined to upstream areas, while A. clausi was restricted downstream Both species showed seasonal variation, peaking during warmer months. Since 2007, A. tonsa exibithed yearly averages consistently above the long-term mean abundance. The results identified a clear effect of temperature warming on the ecosystem, favoring and accelerating the settlement of the non-indigenous species A. tonsa at an unexpectedly rapid rate. STATICO analysis revealed that 2007, 2010 and 2011 were years with strong temporal patterns, which best fitted the compromise analyses between Acartia abundance and environmental parameters. A. tonsa showed an overall positive relationship with temperature, salinity, and total suspended solids (TSS), while A. clausi presented a positive association with chlorophyll a. Local variability of freshwater flow was the dominant signal in the present time-series, and explained the observed dynamics in Acartia populations structure at shorter temporal scales. However, this effect could be masked by larger time-scale phenomena occurring simultaneously, such as a rise in water temperature, leading to a higher abundance of opportunistic tolerant-species, as A. tonsa. These results suggest that copepods living in highly dynamic ecosystems are prone to shifts in community equilibria that show complex, non-linear responses to climatic oscillations.
- Observatório para a Saúde dos Estudantes do Instituto Politécnico de Leiria - Relatório Técnico 2024Publication . Graça Henriques, Carolina Miguel; de Matos Gonçalves, Pedro Jorge; Matos, Rui; Mendes, Susana; Toneca, Cláudia Andreia Cunha Belém; Oliveira Diz, Susana Cristina; Ferreira, BárbaraO Instituto Politécnico de Leiria está comprometido com a promoção de estilos de vida saudável e ativa na comunidade académica, em alinhamento com a definição de Saúde da Organização Mundial de Saúde (OMS). No âmbito do programa Healthy Campus, a saúde, o bem-estar e os estilos de vida saudáveis são preocupações cada vez mais presentes na nossa Instituição, pelo que solicitámos a colaboração de todos os estudantes para o preenchimento de um questionário, devidamente aprovado pela Comissão de Ética do Instituto Politécnico de Leiria - Parecer N.º CE/IPLEIRIA/53/2023, que se realiza no âmbito do Observatório da Saúde dos Estudantes do Politécnico de Leiria, cujos resultados aqui são apresentados e que nos permitem desenhar intervenções que vão ao encontro das necessidades dos nossos estudantes em matéria de saúde, bem-estar e estilos de vida saudáveis.
- Using multitable techniques for assessing the temporal variability of species–environment relationship in a copepod community from a temperate estuarine ecosystemPublication . Cotrim Marques, Sónia; Pardal, Miguel Ângelo; Mendes, Susana; Azeiteiro, Ulisses Manuel de MirandaThis study investigated copepod assemblages' distribution patterns and determined the main hydrological and physical factors structuring it at different temporal scales. Copepod and hydrographic surveys were conducted seasonally during a one-year period, at a fixed station in Mondego estuary. Hourly samples were collected, during a diel cycle from sub-surface and 1m above the bottom, at spring tides. Temporal variability of copepod community was analyzed using the STATICO method. Seasonal variability of the environmental conditions, linked with periods of higher freshwater flow, were the main drivers responsible for copepod community structure observed. Seasonal changes related to environmental factors showed to be strongest in spring and in winter, which accounted with higher species density. Marine and estuarine copepods showed maximal abundance in spring and summer, while the period of higher river flow, coincidently with autumn and winter, imposed changes in the copepods composition, emphasizing the changes in saline zonation within the estuary due to regime of river discharge. STATICO also emphasized the effects of physical forcing at short-term temporal scales. The stable part of the species–environment relationships resulted from the combination of a salinity gradient linked to a fresh, brackish- and marine species gradient, which was dependent on tidal cycle. The STATICO method proved to be a valuable statistical tool to get a clear representation of temporal organization of the copepod assemblages.