Microplastics are known to accumulate in sediment beds of aquatic environments where they can be buried. Once buried they can remobilize due to high energetic events, entering the water column again. Here, turbulence induced by an oscillating grid device was used to investigate the remobilization of microfibers (MF) buried into the sediment bed.
View Article and Find Full Text PDFWetlands produce key ecosystem services to mitigate the impacts of peak flows caused by pluvial or fluvial floods or storm surges. Sediment floods were characterized by a peak flow flowing over a simulated wetland, populated with two natural species. Floods have been drawn as flows of height H, into waters of height h, where H > h.
View Article and Find Full Text PDFSeagrass epiphytic communities act as ecological indicators of the quality status of vegetated coastal environments. This study aims to determine the effect leaf epiphytes has on the sediment capture and distribution from outside sources. Thirteen laboratory experiments were conducted under a wave frequency of 0.
View Article and Find Full Text PDFSci Total Environ
September 2023
Microplastic particles (MP) are an emerging contaminant threatening many aquatic systems. Because of the sharp increase in plastic manufacture, the concentration of MP in natural ecosystems has grown dramatically. While it is known that when MP enter aquatic ecosystems they are transported and dispersed via different mechanisms (currents, waves, turbulence), the processes involved are still poorly understood.
View Article and Find Full Text PDFHabitat degradation in coastal ecosystems has resulted in the fragmentation of coastal aquatic vegetation and compromised their role in supplying essential ecological services such as trapping sediment or sequestering carbon. Fragmentation has changed seagrass architecture by decreasing the density of the canopy or engendering small patches of vegetated areas. This study aims to quantify the role different patch sizes of vegetation with different canopy densities have in the spatial distribution of sediment within a patch.
View Article and Find Full Text PDFSeagrass canopies are coastal ecosystems that are able to modify the abiotic environment through their architectural structure. They have different structural parameters, such as plant stem stiffness, patch length and canopy density, all of which determine their overall functionality in modifying the seafloor hydrodynamics within coastal areas. To determine the interaction between hydrodynamics and the canopy structure, a set of laboratory experiments were carried out with both rigid and flexible stems for different canopy densities, patch lengths and wave frequencies.
View Article and Find Full Text PDFPlastic debris has been found to be ubiquitous in many aquatic ecosystems and is constantly accumulating, not only because more and more plastic is being rapidly released into the environment, but also because its slow degradation means it persists in the water. Some more buoyant plastics accumulate in the water column, whereas other heavier types sink to the bottom. Consequently, the presence of microplastics can threaten organisms living in the water column as well as those found in the benthic zone.
View Article and Find Full Text PDFFor the past two centuries coastal zones have been suffering seagrass loss resulting in a network of vegetated patches which are barely interconnected and which may compromise the ecological services provided by the canopy. To optimize management efforts for successful restoration strategies, questions need to be addressed about what appropriate canopy architectural considerations are required under certain hydrodynamic conditions. In this study, a set of laboratory experiments were conducted in which hydrodynamic conditions, plant densities and vegetated patch lengths were varied to determine minimum patch lengths for successful management strategies.
View Article and Find Full Text PDFDietary polyphenols are multi-target compounds that have been considered promising candidates in strategies for the mitigation of neurological diseases, acting particularly through reduction of microglia-driven neuroinflammation. In this study, an anthocyanin-rich extract obtained from Portuguese blueberries was subjected to a simulated gastrointestinal digestion; after chemical characterisation, the potential of both non-digested and digested extracts to combat neuroinflammation was evaluated using a microglia N9 cell line. Although the extracts have markedly different chemical composition, both were efficient in reducing the production of either key inflammatory markers or reactive oxygen species and in enhancing reduced glutathione levels in activated cells.
View Article and Find Full Text PDFNature-based wastewater treatments are an economic and sustainable alternative to intensive technologies in rural areas, although their efficiency needs to be improved. This study explores technological co-operation between zooplankton (e.g.
View Article and Find Full Text PDFDaphnids, including the water flea Daphnia magna, can be exploited for wastewater treatment purposes, given that they are filter feeder organisms that are able to remove suspended particles from water. The presence of pollutants, such as microplastics and chemicals, might be considered stressors and modify the behaviour and survival of D. magna individuals.
View Article and Find Full Text PDFSci Total Environ
February 2020
Interactions between ecology, hydrodynamics and sediments play central roles in the evolution of coastal and freshwater ecosystems. We set out to characterise interactions of a specific hydrodynamic phenomenon - turbidity currents - with vegetation and sediment dynamics. We measured hydrodynamics and sediment deposition rates when turbidity currents flowed into plant canopies in a lock-exchange flume experiment, using simulated vegetation and three real plant species, and varying the turbidity current's initial sediment concentration.
View Article and Find Full Text PDFDaphnia populations are present in lakes and ponds. They are known to experience diurnal vertical migrations according to their feeding needs. During the day they migrate downwards to avoid predation in light-receiving layers and at night they migrate upwards, searching for food in the shallow productive layers.
View Article and Find Full Text PDFThere is consensus on the need to study the potential impact microplastics (MP) have on freshwater planktonic organisms. It is not yet fully understood how MP enter the aquatic food web or the effect they have on all the trophic levels. As a result of the potential for MP to accumulate throughout food webs, there is increasing interest in evaluating their fate in a variety of environmental conditions.
View Article and Find Full Text PDFDaphnia are important to understanding the biogeochemistry of aquatic ecosystems, mainly because of their ability to filter bacteria, algae and inorganic particles as well. Although there are many studies on the general effects that biotic and abiotic stressors, increased temperature and hypoxia, salinity, metals, pharmaceuticals, pesticides, etc., have on Daphnia populations, little is known about the impact elevated turbulence has.
View Article and Find Full Text PDFAnalysing the effect water temperature has on Daphnia magna is essential in anticipating the impact climate change will have on this freshwater zooplanktonic keystone species. While many authors have followed this line of research, few have covered an extensive temperature range or complex temperature change scenarios. Global warming is mostly associated with increased extreme temperature events, such as heat waves, as well as earlier and more intense thermal stratification.
View Article and Find Full Text PDFBiological methods are a promising approach to treating wastewater in order to produce water of an appropriate quality for sub-potable water purposes, thus reducing pressure on potable water sources. Daphnia magna are organisms that filter on small suspended particles and bacteria and so may be able to clarify and disinfect wastewater. However, Daphnia magna are sensitive to common chemicals and might be vulnerable to the quality of the wastewater.
View Article and Find Full Text PDFCanopy fragmentation increases both spatial heterogeneity and patch edges which, in turn, is then likely to modify the local hydrodynamics in the canopy. The orientation of the edge versus the wave and current field is also expected to play an important role in determining wave attenuation and sheltering at the edge of a canopy. We investigated the effect a longitudinal edge (i.
View Article and Find Full Text PDFDaphnia are filter feeder organisms that prey on small particles suspended in the water column. Since Daphnia individuals can feed on wastewater particles, they have been recently proposed as potential organisms for tertiary wastewater treatment. However, analysing the effects of hydrodynamics on Daphnia individuals has scarcely been studied.
View Article and Find Full Text PDFBackground: In the Balearic Islands, as in other areas of the Mediterranean basin, there is a significant proportion of asymptomatic Leishmania (L.) infantum-infected blood donors, who may represent an important threat to transfusion safety. The Balearic Islands blood bank, located in an area endemic for L.
View Article and Find Full Text PDFObjective: To correlate imaging parameters from baseline MRI diffusion-weighted imaging (DWI) and fludeoxyglucose (FDG) positron emission tomography (PET)-CT with synchronous and metachronous metastases in mucinous carcinoma (MC) and non-mucinous carcinoma (NMC) rectal cancer.
Methods: 111 patients with extraperitoneal locally advanced rectal cancer, who underwent pelvic MRI, DWI and FDG PET-CT, were stratified into MC (n = 23) and NMC (n = 88). We correlated adverse morphologic features on MRI [mT4, mesorectal fascia involvement, extramural venous invasion (mEMVI), mN2] and quantitative imaging parameters [minimum apparent diffusion coefficient (ADC), maximum standardized uptake value, total lesion glycolysis, metabolic tumour volume, T weighted and DWI tumour volumes] with the presence of metastatic disease.
The systematic creation of gaps within canopies results in fragmentation and the architecture of fragmented canopies differs substantially from non-fragmented canopies. Canopy fragmentation leads to spatial heterogeneity in hydrodynamics and therefore heterogeneity in the sheltering of canopy communities. Identifying the level of instability due to canopy fragmentation is important for canopies in coastal areas impacted by human activities and indeed, climate change.
View Article and Find Full Text PDFParasit Vectors
September 2014
Background: Although the Mediterranean island of Majorca is an endemic area of leishmaniosis, there is a lack of up-to-date data on its sand fly fauna, the last report dating from 1989. The aim of the present study was to provide information on the current sand fly distribution, the potential environmental factors favoring the presence of Phlebotomus perniciosus and which areas are at risk of leishmaniosis.
Methods: In July 2008 sand fly captures were carried out in Majorca with sticky castor oil interception traps.