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- The effects of season and wrack subsidy on the community functioning of exposed sandy beachesPublication . Gonçalves, Sílvia; Marques, João C.Seasonality is an important component of the climate, known to influence several biological events that can be reflected in community structure and organization. However, sandy beach macrofaunal community ecological studies are frequently based on snapshot sampling events, neglecting this important dimension and its effects. In the present study, the effects of seasons and wrack subsidies on macrofaunal communitie’s function of two similar exposed sandy beaches of Portugal was monitored for approximately 18 months by sampling all the beach area, from the shoreline to the base of the dunes. The study assessed the beach physical environment, community density and composition, trophic structure, secondary production of key species and the potential relationships between biological data and environmental parameters. Seasonality, particularly temperature variations, and the interaction between seasons and the beach zones (supralittoral vs. intertidal areas) had a strong influence on the communities, promoting a differential utilization of the beach by several species. Seasons also shaped the density of trophic groups, with consequences in community composition and function. Differences between beaches were observed on wrack subsidy, community composition and relative contribution of the dominant species, but the trophic structure was stable and dominated by scavengers. Talitrus saltator was the most productive key species, and the contribution of the resident key species regarding secondary productions and standing stocks was different between beaches. Wrack quantity and deposition frequency on the beach had a positive influence on several faunal descriptors such as density and number of species of various functional groups. The present study also highlights the clear dependence of macrofauna of exposed sandy beaches on the wrack subsidies brought ashore by the tides, illustrating their role on community organization regarding several wrack-associated species and not only scavengers.
- The study of bacterioplankton dynamics in the Berlengas Archipelago (West coast of Portugal) using the HJ-biplot methodPublication . Maranhão P.; Mendes, Susana; Fernández-Goméz, M. J.; Galindo-Villardón, M. P.; Azeiteiro, Ulisses; Bacelar-Nicolau, PaulaThe relationship between bacterioplankton and environmental forcing in the Berlengas Archipelago (Western Coast of Portugal) were studied between February 2006 and February 2007 in two sampling stations: Berlenga and Canal, using an HJ-biplot. The HJ-biplot showed a simultaneous display of the three main metabolic groups of bacteria involved in carbon cycling (aerobic heterotrophic bacteria, sulphate-reducing bacteria and nitrate-reducing bacteria) and environmental parameters, in low dimensions. Our results indicated that bacterial dynamics are mainly affected by temporal gradients (seasonal gradients with a clear winter versus summer opposition), and less by the spatial structure (Berlenga and Canal). The yearly variation in the abundance of aerobic heterotrophic bacteria were positively correlated with those in chlorophyll a concentration, whereas ammonium concentration and temperature decreased with increasing phosphates and nitrites concentration. The relationship between aerobic heterotrophic bacteria, chlorophyll a and ammonium reveals that phytoplankton is an important source of organic substrates for bacteria.
- The effect of sewage discharge on Melarhaphe neritoides (Gastropoda: Littorinidae) population dynamicsPublication . Cabral-Oliveira, J.; Maranhão, Paulo; Pardal, M. Â.The discharges of sewage effluent treatment plants has a major impact on coastal communities. In our study area (western coast of Portugal) Melarhaphe neritoides (L. 1758) is the dominant high-shore gastropod. Two populations of M. neritoides were studied in order to understand the impact of sewage discharges on intertidal communities: one popula tion in an impacted area and the other in a similar but unimpacted area (reference site). Environmental data and abundance, biomass, population structure and annual growth production of M. neritoides were estimated in the two areas. The results showed that M. neritoides density is higher in the impacted area as a result of massive settlement. The sewage discharge increases the nutrient concentrations in the water, which causes more microalgae to grow on the rocky surfaces. This higher availability of food may promote recruitment. However, we found high mortality in the juveniles in the impacted area, which affected density values on the upper shore levels (where we found the adults) of both areas. Moreover, the adults were bigger in the unimpacted area, which suggests that individuals grow more or live longer in this area.
- Fish diversity in the Berlengas Natural Reserve (Portugal), a marine protected areaPublication . Maranhão, Paulo; Vasco Rodrigues, Nuno; Mendes, Susana; Franco, João; Castanheira, Maria; Castro, NunoSince 1981, Berlengas, an archipelago located about 7 miles off Peniche (Western Coast of Portugal), became a marine protected area. Underwater visual census, namely rover diver counts, were used to assess the fish species present in the area during two summer campaigns, 2004 and 2005, comprising a total of 16 hours of scuba diving observations. This study aimed to obtain a more accurate and detailed checklist of the fish species present in the archipelago than the one already existing in result of a few previous studies. A total of 48 fish species belonging to 22 different families were observed during the two study periods. Labridae and Sparidae were the most represented families and Diplodus vulgaris and Labrus bergylta were the most frequent species.
- Effects of sewage pollution on the structure of rocky shore macroinvertebrate assemblagesPublication . Cabral-Oliveira, J.; Mendes, S.; Maranhão P.; Pardal, M. A.The urgency to find efficient indices and indicators to prevent further deterioration of coastal areas is one of the hot topics in today’s scientific publication. However, a detailed knowledge of community responses to anthropogenic impacts is essential to sustain those indices. The studies on the response of benthic community to sewage pollution on intertidal rocky shores are generally based on visual census and do not take into account the tidal levels. In order to fulfil this gap in this study: (i) the sampling was performed by destructive sampling, with all individuals identified to the species level; (ii) the sampling was done at all levels of the intertidal (sublittoral fringe, eulittoral, and littoral fringe). Sewage pollution changed the environmental variables and the abundance of macroinvertebrates, being Mytilus galloprovincialis, Melarhaphe neritoides, and Chthamalus montagui the species most responsible for the dissimilarities observed. Effects were different on the three intertidal zones: community structure changed in the sublittoral fringe; suspension-feeders abundances and species richness increased in the eulittoral; no differences were detected in the littoral fringe. Moreover, the results confirm that the presence of sewage discharges tended to benefit suspension feeders, and that the sensitive species were replaced by opportunistic ones.
- Zinc and cadmium concentrations in soft tissues of the red swamp crayfish Procambarus clarkii (Girard, 1852) after exposure to zinc and cadmiumPublication . Maranhão, Paulo; Marques, João C.; Madeira, Victor M.C.Zinc and cadmium concentrations in crayfish (Procambarus clarkii) soft tissues (as edible portion) were measured after exposure to zinc and cadmium at 0, 25, 50, or 100 mg/L for 96 h at 10 or 208C, and compared to environmental standards for human consumption. Results demonstrated that no significant change occurred in the concentrations of zinc in soft tissues of crayfish under the given conditions. Net accumulation of cadmium was observed at all experimental exposures, and exceeded the maximum allowed for human consumption only for those crayfish exposed to 100 mg/L at 208C.
- Pre- and Postharvest Determinants, Technological Innovations and By-Product Valorization in Berry Crops: A Comprehensive and Critical ReviewPublication . Gonçalves, Elsa M.; Ganhão, Rui; Pinheiro, JoaquinaBerries—including strawberries, blueberries, raspberries, blackberries, cranberries, and several less commonly cultivated berry species—are highly valued for their sensory quality and rich content of bioactive compounds, yet they are among the most perishable horticultural products. Their soft texture, high respiration rate, and susceptibility to fungal pathogens lead to rapid postharvest deterioration and significant economic losses. This review synthesizes advances in berry postharvest management reported between 2010 and 2025. Conventional strategies such as rapid precooling, cold-chain optimization, controlled and modified atmospheres, and edible coatings are discussed alongside emerging non-thermal technologies, including UV-C light, ozone, cold plasma, ultrasound, biocontrol agents, and intelligent packaging systems. Particular emphasis is placed on the instability of anthocyanins and other phenolic compounds, microbial spoilage dynamics, and the influence of cultivar genetics and preharvest factors on postharvest performance. The review also highlights opportunities for circular-economy applications, as berry pomace, seeds, and skins represent valuable sources of polyphenols, dietary fiber, and seed oils for use in food, nutraceutical, cosmetic, and bio-based packaging sectors. Looking ahead, future research should prioritize integrated, multi-hurdle, low-residue postharvest strategies, the scale-up of non-thermal technologies, and data-driven cold-chain management. Overall, coordinated physiological, technological, and sustainability-oriented approaches are essential to maintain berry quality, reduce postharvest losses, and strengthen the resilience of berry value chains.
- Effects of thermal stress on the immune and oxidative stress responses of juvenile sea cucumber Holothuria scabraPublication . Kamyab, Elham; Kühnhold, Holger; Novais, Sara C.; Alves, Luís M. F.; Indriana, Lisa; Kunzmann, Andreas; Slater, Matthew; Lemos, Marco F. L.Holothuria scabra is the most valued and cultured tropical sea cucumber, given the great demand of this species for human consumption. However, despite its ecological and economic relevance, little is known regarding its immune responses under thermal stress. Here, the main goal was to study the response of sea cucumbers to temperature stress, assessing sub-organismal alterations and acclimation capacities of juveniles to temperature changes. After changing temperature (1 °C/day) for 6 days, organisms were exposed to temperature conditions of 21 °C (cold), 27 °C (control), and 33 °C (warm) over a 30 day period. At each 15-day interval (T0, T15, and T30), six replicates per condition were killed for biochemical analysis. Immune responses were addressed by studying the activity of phenoloxidase (PO) and prophenoloxidase (ProPO) in the coelomic fluid. Antioxidant defence responses-catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) enzymatic activities-were measured in the muscle and respiratory tree tissues, whereas oxidative damage was evaluated by measuring levels of superoxide radicals (ROS), DNA-strand breaks and lipid peroxidation (LPO). Juvenile H. scabra increased SOD and PO activities when temperature was elevated, and revealed low levels of ROS and damage in both cold and warm treatments throughout the experiment, confirming the organism's moderate thermal stress. After the short acclimation period, the immune and antioxidant responses prevented damage and maintained homeostasis. This multi-biomarker approach highlights its usefulness to monitor the health of H. scabra and to gain insight concerning the use of this high-valued species in global-scale aquaculture from different temperature regions.
- Survival of Corbicula fluminea (Müller, 1774) in a natural salinity and temperature gradient: a field experiment in a temperate estuaryPublication . Crespo, Daniel; Leston, Sara; Martinho, Filipe; Pardal, Miguel A.; Dolbeth, MarinaThe invasive bivalve Corbicula fluminea is described as a freshwater species but can colonize estuarine upper reaches. In a 46-day field experiment, the survival ability of the species along an estuarine gradient was tested. Our goal was to understand its tolerance limits in a transitional area and in which conditions a potential invasion in the estuary could thrive, in order to predict the potential threat of the species distribution and settlement along the freshwater–estuarine continuum. The Lethal Time (LT) method was adapted to this field test with success. The population held an adult stock in the most upstream areas of the estuary (salinity <0.5). Dispersal mechanisms allowed the species to be present in the downstream areas, however, with a different population structure as consequence of the interaction of the diverse physico-chemical gradients of the estuary, in particular different salinity and temperature combinations. During winter, the species was able to survive in all test sites, with practically no mortality, while in summer LT50 (median lethal time) changed considerably when comparing the upstream and the most downstream sites [82 days (predicted value) vs. 9 days, respectively]. Still, 100% mortality was never achieved, adding concern to the species invasion potential in this estuary.
- Oxidative stress responses of Daphnia magna exposed to effluents spiked with emerging contaminants under ozonation and advanced oxidation processesPublication . Oropesa, Ana Lourdes; Novais, Sara C.; Lemos, Marco F. L.; Espejo, Azahara; Gravato, Carlos; Beltrán, FernandoIntegration of conventional wastewater treatments with advanced oxidation processes (AOPs) has become of great interest to remove pharmaceuticals and their metabolites from wastewater. However, application of these technologies generates reactive oxygen species (ROS) that may reach superficial waters through effluents from sewage treatment plants. The main objective of the present study was to elucidate if ROS present in real effluents after biological and then chemical (single ozonation, solar photolytic ozonation, solar photocatalytic ozonation (TiO2, Fe3O4) and solar photocatalytic oxidation (TiO2)) treatments induce oxidative stress in Daphnia magna. For this, the activity of two antioxidant enzymes (superoxide dismutase and catalase) and the level of lipid peroxidation were determined in Daphnia. The results of oxidative stress biomarkers studied suggest that D. magna is able to cope with the superoxide ion radical (O2·-) present in the treated effluent due to single ozonation by mainly inducing the antioxidant activity superoxide dismutase, thus preventing lipid peroxidation. Lethal effects (measured in terms of immobility) were not observed in these organisms after exposure to any solution. Therefore, in order to probe the ecological efficiency of urban wastewater treatments, studies on lethal and sublethal effects in D. magna would be advisable.