Encontrados 10 documentos, a visualizar página 1 de 1
Population ecology and habitat preferences of juvenile flounder Platichthys fle...
Souza, Allan T.; Dias, Ester; Nogueira, Ana; Campos, Joana; Marques, João C.; Martins, IreneThe European flounder Platichthys flesus is a widely distributed epibenthic species and an important component of demersal fish assemblages in the European Atlantic coastal waters. In Portuguese estuaries, this species reaches high densities, especially in Minho estuary (NW Iberian Peninsula, Europe), potentially playing an important role in the system's ecology. In this context, the population structure, produ...
[delta]15N and [delta]13C in the Mondego estuary food web: Seasonal variation i...
Baeta, Alexandra; Pinto, Rute; Valiela, Ivan; Richard, Pierre; Niquil, Nathalie; Marques, João C.http://www.sciencedirect.com/science/article/B6V7H-4V1KMR2-1/2/b800195eaff45d3f8489262b01e043d2
Sandy beach macrofaunal communities on the western coast of Portugal - Is there...
Gonçalves, Sílvia C.; Anastácio, Pedro M.; Pardal, Miguel A.; Cardoso, Patrícia G.; Ferreira, Susana M.; Marques, João C.http://www.sciencedirect.com/science/article/B6WDV-4V4VYC0-2/2/c968e2b21c463c15e0eaf55b40b10a1a
Feeding ecology of the green crab, Carcinus maenas (L., 1758) in a temperate es...
Baeta, Alexandra; Cabral, Henrique N.; Marques, João C.; Pardal, Miguel A.The feeding ecology of Carcinus maenas was studied between June 2003 and June 2004 in three areas in the Mondego estuary, Portugal. Samples were collected monthly, during the night, at high water of spring tides using a 2 m beam trawl. Among 837 stomachs examined, 25 different food items were identified. Crangon crangon, Hediste diversicolor, and Teleostei were the most important food items by occurrence, numbe...
Impact of eutrophication and river management within a framework of ecosystem t...
Marques, João C.; Nielsen, Søren N.; Pardal, Miguel A.; Jørgensen, Sven E.Eutrophication became a dominant process in the Mondego estuarine system in the 1980s, presumably as a result of excessive nutrient release into coastal waters. The main symptoms were the occurrence of seasonal blooms of Enteromorpha spp., green macroalgae, and a drastic reduction of the Zostera noltii meadows. Previous results suggest that this process will determine changes in species composition at other tro...
Dicionário virtual de ornitologia e ecologia: as novas tecnologias de informaçã...
Almeida, Luís; Lopes, Ricardo; Marcos, Adérito; Marques, João C.1º Encontro de Observadores de Aves das Arribas do Douro, Solar dos Marcos, Bemposta, Mogadouro, 26-27 Julho 2003. ; Este artigo apresenta o projeto “Dicionário Virtual de Ornitologia e Ecologia”, que pretende tirar partido do veículo de divulgação por excelência que é a Internet para divulgar informação científica, nas áreas da Ornitologia e Ecologia. Na sequência de um trabalho anterior, e com o apoio do min...
Degradability and Sediment Sorption of an Alcohol Polyglycol Ether Surfactant P...
Fonseca, Júlio C.; Marques, João C.; Madeira, Vítor M. C.This work reports studies of the degradation rates of a fattyalcohol polyglycol ether non-ionic surfactant, Genapol OXD-080, putatively useful for the control of red swamp crayfish (Procambarus clarkii Girard) in rice fields under laboratory and field conditions. The influence of temperature,sediment site specificity and sorption were taken into account.The degradation kinetics of the surfactant depends on the ...
Estimation of ecological exergy using weighing parameters determined from DNA c...
Fonseca, Júlio C.; Pardal, Miguel A.; Azeiteiro, Ulisses M.; Marques, João C.We studied the changes of exergy and specific exergy with data of benthic macrofauna communities, periodically sampled along an estuarine gradient of eutrophication in the Mondego estuary (Western Portugal). Exergy estimates were calculated from organism biomass, based on weighing factors for the relative content of exergy per unit of biomass determined from DNA contents of organisms. Results were discussed in ...
Impact of macroalgal blooms and wader predation on intertidal macroinvertebrate...
Lopes, Ricardo J.; Pardal, Miguel A.; Marques, João C.The effect of macroalgal blooms and predation by wading on benthic macroinvertebrates was examined in the Mondego estuary, Portugal, during spring 1997. Introduced macroalgal cover and exclusion of predators were used to examine changes in density of macroinvertebrates using univariate and multivariate analyses. There was no evidence of changes in numbers of macroinvertebrates due to predation. Macroalgae were,...
Nuclear DNA in the determination of weighing factors to estimate exergy from or...
Fonseca, Júlio C.; Marques, João C.; Paiva, Artur A.; Freitas, Albertina M.; Madeira, Vítor M. C.; Jørgensen, Sven E.The application of ecological exergy as a suitable system-oriented development indicator of ecosystems and the estimation proposals from biomass are revised. DNA contents (C-values) of several groups of organisms are figured, either determined by flow cytometry or taken from literature. The applicability of DNA contents for determination of weighing factors to estimate ecological exergy from the biomass of orga...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||