Browsing by Author "Chainho, P."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- 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).
- 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.