The Duero Diatom Index (DDI) for river water quality assessment in NW Spain: design and validation

Diatom indices developed in certain geographic regions are frequently used elsewhere, despite the strong evidence that such metrics are less useful when applied in regions other than that where species–environment relationships were originally assessed, showing that species have particular autoecological requirements in different geographic areas. The goal of this study was to develop a new metric, the Duero Diatom Index (DDI), aimed at monitoring water quality in Duero basin watercourses (NW Spain). In summer 2008 and 2009, a total of 355 epilithic diatom samples were collected following standard protocols. The 2008 samples were used to develop the DDI, whereas the samples collected during 2009 were used in the index testing. Weighted averages method was used to derive the autoecological profiles of diatoms with respect to pH, conductivity, biological oxygen demand, ammonia, nitrates, and phosphates. The optimum and tolerance values for the measured environmental variables were determined for 137 taxa with abundances and frequencies of occurrence above 1 %, and subsequent trophic indicator and sensitivity values were defined for the DDI. The correlation between the observed and the diatom-inferred nutrient concentrations was highest for phosphates (ρ _S?=?0.72). Significant statistical relationship were observed between DDI values and the chemistry-based General Quality Index values (p?=?0.006) and the specific pollution index (SPI) diatom metric (p?=?0.04). DDI has demonstrated a better correlation with water chemistry than SPI diatom metric.     

Study of a coupled adsorption/electro-oxidation process as a tertiary treatment for tequila industry wastewater

Environmental Science and Pollution Research - Vinasse wastewater from tequila industry that has been conventionally treated is usually characterized by a chemical oxygen demand (COD) above...     

A data synthesis on the biochar properties and implications for air,soil, and water quality in Brazil

Biochar has been intensively researched worldwide. In Brazil, there is a variety of feedstock production that can be turned into soil amendments of high performance through biochar conversion, especially solid wastes. However, advances in biochar research in Brazil have not been systematically evaluated to indicate possible gaps and suggest future research for eco-friendly applications. Thus, in this work we evaluated biochar properties and effects on air, water, and soil quality based on data gathered from researches performed in Brazil. Biochar has been mainly evaluated as soil conditioner (37%), material characterization (17%), water treatment (12%), and greenhouse gases emissions (9%). Based on the data synthesis of 68 feedstocks used for biochar production, we observed that the pyrolysis temperature profoundly affects biochar properties. Meta-analysis indicated benefits of biochar addition to soils for chemical, physical, microbiological and biochemical attributes that have resulted in increases in root growth (+30%), and plant shoots (+45%). Pyrolysis temperature and feedstock are key choices to design biochar properties aiming to retain dyes, aromatic hydrocarbon, pesticides, and metals in water and wastewater treatment. It was also observed an increase in CO₂ and a decrease in N₂O emissions after biochar application to soils in short-term experiments. Although there is a growing interest in the development of electrochemical sensors and biochar-based fertilizers, technological applications of biochar are still incipient in Brazil. Future research should prioritize long-term and mechanistically evaluations of biochar under field conditions and the development of eco-friendly technological applications.     

Nanomaterials for water cleaning and desalination,energy production,disinfection, agriculture and green chemistry

Nanomaterials may help to solve issues such as water availability, clean energy generation, control of drug-resistant microorganisms and food safety. Here we review innovative approaches to solve these issues using nanotechnology. The major topics discussed are wastewater treatment using carbon-based, metal-based and polymeric nanoadsorbents for removing organic and metal contaminants; nanophotocatalysis for microbial control; desalination of seawater using nanomembranes; energy conversion and storage using solar cells and hydrogen-sorbents nanostructures; antimicrobial properties of nanomaterials; smart delivery systems; biocompatible nanomaterials such as nanolignocellulosis and starches-based materials, and methods to decrease the toxicity of nanomaterials. Significantly, here it is reviewed two ways to palliate nanomaterials toxicity: (a) controlling physicochemical factors affecting this toxicity in order to dispose of more safe nanomaterials, and (b) harnessing greener synthesis of them to bring down the environmental impact of toxic reagents, wastes and byproducts. All these current challenges are reviewed at the present article in an effort to evaluate environmental implications of nanomaterials technology by means of a complete, reliable and critical vision.     

Parasitic castration in slipper limpets infested by the symbiotic crab Calyptraeotheres garthi

Two ill-explored hypotheses might explain host castration by parasitic pea crabs. The ‘energy drain’ hypothesis states that castration is caused by host-derived nutrient consumption of parasites that ultimately diminishes host-energy intake. The ‘steric interference’ hypothesis states that castration occurs when parasites physically inhibit host reproduction. This study evaluated whether Calyptraeotheres garthi, a pea crab from the southwestern Atlantic, is a parasitic castrator and explored whether the two hypotheses above explain castration in the limpet Crepidula cachimilla. None of three studied limpet species brooded embryos during the reproductive season when infested by mature female pea crabs. Also, limpets of C. cachimilla infested by C. garthi did not reproduce during a 90-day experimental period while crab-free limpets did spawn embryos during this period. Limpets resumed reproduction soon after pea crabs were experimentally removed from their brooding chamber. Thus, C. garthi does castrate limpets, and castration is reversible. Pea crabs ‘steal’ food from limpets, and infested limpets did not modify their feeding behavior to counteract nutrient loss. Thus, infested limpets are expected to ingest less food which provides partial support for the ‘energy drain’ hypothesis. However, the limpet’s body condition increased or was not affected by pea crabs during the breeding season which argues against the same hypothesis. Furthermore, that limpets promptly recovered reproductive activity once pea crabs were experimentally removed, that castration was not induced by the smallest pea crabs in the population (that fill only partially the brooding chamber), and that parasitized limpets did exhibit fully mature ovaries, support the ‘steric interference’ hypothesis explaining parasitic castration.     

Correction to: Health risk assessment of hexachlorocyclohexane in soil,water and plants in the agricultural area of Potohar region,Punjab, Pakistan

Environmental Geochemistry and Health - A correction to this paper has been published: https://doi.org/10.1007/s10653-021-00910-5     

Beak colour reflects circulating carotenoid and vitamin A levels in spotless starlings (Sturnus unicolor)

Many colourful sexually selected signals in animals are carotenoid-dependent and, because carotenoids function as antiradicals and immunostimulating molecules, carotenoid-dependent signals may honestly reflect the health state of individuals. Some others nutrients like vitamin A may also enhance health and colouration, but these have rarely been tested alongside carotenoids in colourful birds. Here, we examined whether beak colour of the spotless starling (Sturnus unicolor) reflected circulating levels of carotenoids and/or vitamin A (retinol). Spotless starlings are polygynous, sexually dimorphic birds (i.e. length of chest feathers). The tip of the beaks of male and female spotless starlings is more intensely coloured at the beginning of the breeding season and becomes dull after mating, which may suggest a sexual function. We found that females have a more intensely coloured beak and higher plasma carotenoid concentration than males during mating, and, despite the finding that carotenoid and vitamin A levels were not significantly related; colour intensity was positively correlated with plasma concentration of carotenoids and vitamin A in both sexes. However, adult beak coloration was not associated with carotenoid and vitamin A concentrations after nestlings were hatched. Therefore, beak colouration of spotless starlings provides information about circulating levels of carotenoids and vitamins during the mating season and may potentially function as a reliable signal of physiological status in the context of sexual selection.     

Coastal setbacks for the Mediterranean: a challenge for ICZM

Coastal development along the Mediterranean coast needs to be tackled with an integrated approach, in order to safeguard people and properties from extreme events, maintain environmental flows and ecosystems functions, protect coastal landscapes and ensure public accessibility to the shore. The complexity of the Mediterranean countries legal and administrative framework and its morphological heterogeneity make the implementation of new the Protocol on ICZM provisions on coastal setbacks,—claiming for a 100 m wide buffer zone where construction is not allowed— a challenge for the success of the initiative. European countries and the European Commission are party to the protocol but the European legal framework lacks of specific provisions addressing the definition of coastal setbacks. Moreover, climate change, in terms of sea level rise and maritime climate, could play a major role in the future position of setback lines. While arbitrary setbacks should be put in place to halt short-term unwise coastal development, science can improve the identification of coastal setbacks by providing integrated methodologies to be implemented at the local level. The objective of this paper is to review concepts and practices in the use of coastal setbacks, in the context of the provisions of the ICZM protocol and taking into account new challenges posed by climate change. A stepwise route map is proposed as a base to identify coastal setbacks, applicable to the Mediterranean region and elsewhere, to be used as a base to improve arbitrary setback approaches.     

Coastal setbacks for the Mediterranean: a challenge for ICZM

Coastal development along the Mediterranean coast needs to be tackled with an integrated approach, in order to safeguard people and properties from extreme events, maintain environmental flows and ecosystems functions, protect coastal landscapes and ensure public accessibility to the shore. The complexity of the Mediterranean countries legal and administrative framework and its morphological heterogeneity make the implementation of new the Protocol on ICZM provisions on coastal setbacks,—claiming for a 100 m wide buffer zone where construction is not allowed— a challenge for the success of the initiative. European countries and the European Commission are party to the protocol but the European legal framework lacks of specific provisions addressing the definition of coastal setbacks. Moreover, climate change, in terms of sea level rise and maritime climate, could play a major role in the future position of setback lines. While arbitrary setbacks should be put in place to halt short-term unwise coastal development, science can improve the identification of coastal setbacks by providing integrated methodologies to be implemented at the local level. The objective of this paper is to review concepts and practices in the use of coastal setbacks, in the context of the provisions of the ICZM protocol and taking into account new challenges posed by climate change. A stepwise route map is proposed as a base to identify coastal setbacks, applicable to the Mediterranean region and elsewhere, to be used as a base to improve arbitrary setback approaches.     

Influence of increased cod abundance and temperature on recruitment of northern shrimp (Pandalus borealis)

Despite an increase in northern shrimp (Pandalus borealis) female biomass in the past years, the recruitment of the offshore population north and northeast of Iceland has remained very low. In this study, the influence of abiotic and biotic factors was studied in relation to shrimp recruitment. Two factors, cod (Gadus morhua) abundance and summer sea surface temperature (SST), were found to have a negative effect on offshore shrimp recruitment, explaining 71 % of the observed variation. Both cod abundance and temperature on the offshore shrimp grounds have increased in the past years, while recruitment has decreased and been at historically low levels since 2005. No significant relationship was found between recruitment and spawning biomass, indicating that recruitment variability is mainly driven by other factors. Cod abundance and summer SST are likely to affect different life stages of shrimp, as SST influences shrimp during its planktonic phase while cod abundance influences the demersal stage.