Environmental monitoring using surface water, river sediments, and vegetation: A case study in the Famatina Range, La Rioja, NW Argentina

This work discusses trace elements studied beneath the semiarid endorheic region of the Famatina Range (La Rioja, NW Argentina). The results obtained in 27 control sites allow the determination of five distinct geochemical patterns in the Famatina Range. Pattern 1 reflects the composition of underlying Paleozoic and Tertiary bedrock (background level: water pH, 7.5–9; specific conductance, 0.2–0.7 mS cm⁻¹), which is influenced by mineralization. Pattern 2 exhibits water pH, 6; specific conductance, 0.7 mS cm⁻¹; high contents of Cu, Cd, Rb, Zn, Sn, and Be in waters; and high contents of Cu, Cd, Zn, Pb, Cr, Sb, Ag, Be, Co, Ni, Bi, Rare Earth Elements (REE), Li, Ba, Cs, and Sr in sediments. Pattern 3 exhibits water pH, 3–4; specific conductance, 1.0 mS cm⁻¹; high contents of Pb, Co, Be, Au, As, Cr, Hg, Th, Ba, Cs, Rb, Sb, Y, Zr, REE, and Hf in waters; high contents of Cd, Zn, Mo, and As in sediments). Pattern 3 is also modified by the input of elements from a source external to the Famatina Range. Pattern 4 exhibits water pH, 7–8; specific conductance, 1.5–2.3 mS cm⁻¹; high contents of B, Li, Ba, Sr, and Zn in waters; high contents of Li, Cr, Sr, Ni, and Cs in sediments. Finally, Pattern 5 is developed on the red sandstones from De la Cuesta Formation (water pH, 8; specific conductance, 2.5–5.0 mS cm⁻¹; high contents of Sr, Mo, U, B, Li, Rb, and Hf in waters; high contents of B, Ba, Cs, Li, and Rb in sediments). The mobility of above-mentioned elements is mainly related to water pH changes and evaporation processes.     

Phosphine functionalised multiwalled carbon nanotubes: A new adsorbent for the removal of nickel from aqueous solution

Synthesised triphenylphosphine-linked multiwalled carbon nanotubes (Tpp-MWCNTs) were used to study the adsorption of nickel in aqueous solutions and their adsorption capabilities were compared with purified MWCNTs. The adsorption capacity increased with an increase in pH for all adsorbents. The adsorption equilibrium was reached in 40 and 30 min for purified MWCNTs and Tpp-MWCNTs, respectively. Both Freundlich and Langmuir isotherms used to investigate the adsorption process fitted the experimental data well with the correlation coefficient R² close to 1 for all adsorbents. On the other hand, the experimental data fitted well with a pseudo second-order model. The speciation of nickel also influenced the adsorption on the purified and Tpp-MWCNTs. The adsorbents used in this study showed superior adsorption capacity when compared to other adsorbents reported in the literature.     

The effects of anaerobic reactor post-treatments by rapid filtration systems and conventional techniques

Environmental Science and Pollution Research - Although anaerobic reactors are an excellent alternative in the treatment of domestic effluents, they have the disadvantage of requiring...     

Primary and secondary organic winter aerosols in Mediterranean cities under different mixing layer conditions (Barcelona and Granada)

Environmental Science and Pollution Research - PM10 was collected during an EMEP winter campaign of 2017–2018 in two urban background sites in Barcelona (BCN) and Granada (GRA), two...     

Lights and shadows: growth patterns in three sympatric and congeneric sponges (Ircinia spp.) with contrasting abundances of photosymbionts

The life-history traits of long-lived benthic littoral invertebrates remain poorly understood. In this study, we analysed patterns of growth in three abundant sublittoral sponges from the western Mediterranean Sea, chosen for their close phylogenetic relatedness, sympatric distribution, and contrasting amounts of photosymbionts: high in Ircinia fasciculata, lower in I. variabilis, and absent in I. oros. Sponge area, perimeter, number of oscula, and epibiont abundance were quantified from in situ digital images taken monthly for 1.5 years and volumetric growth rates were calculated from empirical area–volume relationships. Volumetric growth rates were different among species and coherent with the photosymbiont abundance: high in I. fasciculata (40.03 ± 4.81 % year^?1, mean ± SE), low in I. variabilis (5.65 ± 6.11 % year^?1), and almost nil in I. oros (?0.04 ± 3.02 % year^?1). Furthermore, a marked seasonality was observed in the first two species, with greater growth during the warm season. The high growth rates of I. fasciculata were likely fuelled by symbiont-derived photosynthates and required to compete in the well-lit, algal-dominated habitats this species prefers. In contrast, I. variabilis and I. oros tended to dwell in shaded habitats, where competition from slow-growing invertebrates is intense, and featured lower growth rates. The flattened morphology and lower circularity of I. variabilis indicates a capacity for adaptation to any space that is freed, while I. oros had less oscula and was more massive and circular, suggesting a strategy of passive occupation and minimisation of biological interactions. The results show that even congeneric species living sympatrically can achieve important biomass using different growth and substrate occupation strategies.     

The reproductive cycle of the sea urchin Arbacia lixula in northwest Mediterranean: potential influence of temperature and photoperiod

We studied the reproductive cycle of the sea urchin Arbacia lixula in a subtidal population from northeast Spain over four years using a gonadosomatic index (GSI) and gonad histology. Our results show that the GSI of A. lixula follows a seasonal cycle which peaks in May–July and attains its lowest values in October–November every year. The time course of the GSI matched closely the photoperiod cycle. We also found a remarkable inter-annual variability in the maximum value of GSI, which correlated with mean water temperature during the gonad growth period (winter and spring). Gonad histology was also in agreement with a single gametogenic cycle per year in this species. We explored the application of circular statistics to present and analyse gonadal development data, which allowed us to adequately handle the high intra-individual variability detected, with several developmental stages commonly found within the same gonad. The picture that emerged is one of a gametogenic timing driven by photoperiod, while the amount of reproductive output is determined by temperature. This is coherent with the tropical origin of the species and lends support to recent warnings about an increase in the abundance of this species in the Mediterranean as a result of global warming, with associated increased impact potential in sublittoral communities.     

Short- and long-term consistency in the foraging niche of wandering albatrosses

The wandering albatross (Diomedea exulans) is regarded as a generalist predator, but can it be consistent in its foraging niche at an individual level? This study tested short- and long-term consistency in the foraging niche in terms of habitat use, trophic level and, by inference, prey selection. Fieldwork was carried out at Bird Island, South Georgia, in May–October 2009, during the chick-rearing period. Blood (plasma and cells) and feathers for stable isotope analyses (δ¹³C and δ¹⁵N) were sampled from 35 adults on their return from a foraging trip during which they carried stomach temperature, activity and global positioning system loggers. Results suggest short-term consistency in foraging niche in relation to both oceanic water mass and trophic level, and long-term consistency in use of habitat. Consistent differences between individuals partly reflected sex-specific habitat preferences. The proportion of consistent individuals (i.e., with a narrow foraging niche) was estimated at c. 40?% for short-term habitat and trophic level (prey) preferences and 29?% for longer-term habitat preference, suggesting this is an important characteristic of this population and potentially of pelagic seabirds in general. Foraging consistency was not related to body condition or level of breeding experience; instead, it may reduce intraspecific competition.