Ecotoxicological Assessment of Contaminated River Sites as a Proxy for the Water Framework Directive: an Acid Mine Drainage Case Study

Metal contamination of freshwater bodies resulting from mining activities or deactivated mines is a common problem worldwide such as in Portugal. Bra?al (galena ore) and Palhal (pyrrhotite, chalcopyrite, galena, sphalerite, and pyrite ore), located in a riverside position, are both examples of deactivated mining areas lacking implemented recovery plans since their shutdown in the early mid-1900s. In both mining areas, effluents still flow into two rivers. The purpose of this work was to evaluate the potential hazard posed by the mining effluents to freshwater communities. Therefore, short- and long-term ecotoxicological tests were performed on elutriates from river sediments collected at each site using standard test organisms that cover different functional levels (Vibrio fischeri, Pseudokirchneriella subcapitata, Lemna minor, and Daphnia sp.). The results show that elutriates from the sediments of Palhal were very toxic to all tested species, while in contrast, elutriates from Bra?al showed generally no toxicity for the tested species. Our study highlights the usefulness of using an ecotoxicological approach to help in the prioritization/scoring of the most critical areas impacted by deactivated mines. This ecotoxicological test battery can provide important information about the ecological status of each concerning site before investing in the application of time-consuming and costly methods defined by the Water Framework Directive or can stand as a meaningful complementary analysis.     

Evaluation of preflooding effects on iron extractability and phytoavailability in highly calcareous soil in containers

Previous pot cropping and laboratory incubation experiments were consistent with field observations showing that temporary flooding before cropping can increase the availability of soil Fe to plants. To study the effect of temporary flooding on changes in soil Fe phytoavailability we used 24 highly calcareous, Fe chlorosis–inducing soils to carry out a pot experiment where peanut and chickpea were successively grown after flooding for 30 d. At the end of the cropping experiment, the preflooded soil samples exhibited higher concentrations of acid oxalate‐, citrate/ascorbate‐ and diethylenetriaminepentacetic acid (DTPA)–extractable Fe (Fe_ox, Fe_ca, and Fe_DTPA, respectively) than the control (nonflooded) samples. Also, Fe_ox and Fe_ca exhibited no change by effect of reflooding of the cropped soils or three wetting–drying cycles in freeze‐dried slurries of soils previously incubated anaerobically for several weeks. Leaf chlorophyll concentration (LCC) in both peanut and chickpea was greatly increased by preflooding. The best predictor for LCC was Fe_ox, followed by Fe_ca and Fe_DTPA. The LCC–soil Fe relationships found suggest that the Fe species extracted by oxalate and citrate/ascorbate from preflooded soils were more phytoavailable than those extracted from control soils. However, the increased phytoavailability of extractable Fe forms was seemingly limited to the first crop (peanut). Flooding dramatically increased Fe_DTPA; however, high Fe_DTPA levels did not result in high LCC values, particularly in the second crop. Therefore, this test is a poor predictor of the severity of Fe chlorosis in preflooded soils.     

Anatomy,Morphometry and Radiography in the thoracic limb bones of the Patagonian Huemul Deer (Hippocamelus bisulcus)

The aim of this study was to provide morphometric, anatomic and radiographic data of the thoracic limb bones of the Patagonian Huemul (Hippocamelus bisulcus) including a functional interpretation of this, as a reference for clinical use, biomedical research and teaching purposes. Currently, the Patagonian huemul deer is in danger of becoming extinct due to multiple causes. Research carried out for its conservation has focused mainly on its ecology and pathology, leaving gaps in biological knowledge, which is basic and important for its comprehension. This study was conducted to reveal the gross osteology and radiology features of the thoracic limb bones of the Patagonian huemul deer. The osteological findings suggest the presence of powerful flexor muscles in the scapulohumeral and elbow joints, useful to cushion the jumps. Also, the principal nutrient foramen of Patagonian huemul differs in position with respect to domestic ungulates, which may be important to consider during surgical procedures. Finally, the radiographic data can provide new information about the tissue loading conditions in Patagonian huemul, so that this new knowledge can be of great importance for a better understanding of mechanically induced or adaptive changes in bone produced by habitat or other ecological phenomena.     

Effects of irrigation water quality on loquat plant nutrition: Sensitivity of loquat plant to salinity

An investigation was conducted to study the possible use of municipal wastewater for watering loquat plants, and to determine the effects of this water on nutrient status of two‐year‐old loquat plants (Eriobotriae japonica L.) during two complete vegetative cycles. The plants, grafted on franco and Anger stocks, were planted on major soils of the area of La Marina Babea. Plants (grafted on franco stock), irrigated with this wastewater, suffered from foliar necrosis, and all of them died at the end of the experiment, whereas only 12.5% of the plants watered with municipal drinking water died at the same period of time. The Anger stock proved to be much more resistant to salinity than the franco stock. Therefore, medium quality waters (wastewater and saline water) can be used for the irrigation of loquat trees grafted on Anger stock, without causing damages on plant nutrition.     

Use of CLSA and SPME-headspace techniques followed by GC-MS analysis to extract and identify the floral odorants

Flowers of Ziziphus spina christi are known to be attractive for parasitoids and predators. In Y-tube olfactometer experiments, the dried flowers attracted significantly (p < 0.001) the female parasitoids Aphelinus abdominalis. The flower volatile compounds were analyzed to understand which compounds could be specifically responsible for this attractiveness. The volatile compounds of Ziziphus flowers were extracted by closed-loop-stripping-analysis (CLSA) and also by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. The main chemical classes of the volatile compounds are aldehydes, monoterpene-alcohols, ketones and hydrocarbons. Flower extract and some specific compounds will be further tested for their responsiveness to predators and parasitoids in behavioural and electrophysiological experiments.     

Applicability of a rapid chromatographic immunoassay for analysis of the distribution of PrPBSE in confirmed BSE cases

The Prionics-Check PrioSTRIP is a rapid chromatographic immunoassay for bovine spongiform encephalopathy (BSE) approved by the European Union in 2004. In this study, the PrioSTRIP was used to analyse PrP(BSE) in 16 different brain areas of nine confirmed BSE cases. The levels of PrP(BSE) in the different brain areas were plotted to give the brain PrP(BSE) distribution curve (BPDC) and compared with the BPDC obtained previously by Western blotting and enzyme-linked immunosorbent assay (ELISA) methods on the same samples. The distribution of PrP(BSE) in different areas of the brain was similar, irrespective of the test applied, indicating that each test could be used for the characterisation of BSE cases.     

Population dynamics of Xylosandrus compactus (Coleoptera: Curculionidae: Scolytinae) on Coffea canephora in the Lake Victoria Crescent agroecological zone of Uganda

We studied the seasonal population dynamics of Xylosandrus compactus on Coffea canephora for 24 months from June 2013 to May 2015 at the National Coffee Research Institute, Mukono, Uganda. Every month, we randomly sampled 20 infested twigs from different coffee trees on each of three experimental blocks, and dissected them to count different stages of X. compactus per twig. We recorded monthly mean temperature and total rainfall. Seasonal fluctuations in numbers of different life stages of X. compactus inside C. canephora twigs over time were analysed with a general linear model. Ambient temperature and rainfall were used to predict changes in monthly mean counts by means of a multiple linear regression. The population of X. compactus varied significantly across months and its major peak occurred from May to August. This variability was poorly explained by prevailing weather conditions with only the number of dead females correlated negatively with mean monthly temperature. Therefore, it may be suitable to apply management interventions against X. compactus on C. canephora in Uganda prior to May–August of each year to prevent the pest from attaining damaging levels. Further research is necessary to better understand the effect of weather variables on population dynamics of this insect pest.     

Determination of poly‐β‐hydroxybutyrate assimilation by postlarval whiteleg shrimp,Litopenaeus vannamei using stable 13C isotope tracing

A preliminary study was conducted to demonstrate fate of the bacterial storage compound poly‐β‐hydroxybutyrate (PHB) once ingested and degraded in vivo in crustaceans. The 2% supplementation of ¹³C‐labeled Ralstonia eutropha DSM545 containing 75% PHB on dry weight in postlarval whiteleg shrimp, Litopenaeus vannamei resulted in consistent enrichment of two fatty acids (containing 14–24 carbons [C] in length ) pentadecanoic acid (15:0) and palmitic acid (16:0) in all lipid fractions. This could indicate that ¹³C signal may not only originate from the PHB but partly from the structural components of the bacterial cell. There was a trend of lower ¹³C enrichment in various lipid fractions of the postlarvae as compared to the diet. These findings may have important implications as to potential of PHB as energy source rather than as building block. There was a rapid transfer of ¹³C in the postlarvae as seen by the significant ¹³C enrichment in the tissues 4 hr after feeding with labeled bacterial cells. Overall, the assimilation of PHB in crustacean tissues is demonstrated for the first time. Our results indicate that PHB once ingested is rapidly assimilated in the tissues and could probably act as an energy source rather than as a building block.     

Developmental stages during the rooting of in-vitro-cultured Quercus robur shoots from material of juvenile and mature origin

In-vitro-cultured shoots of clones initiated from shoots of the basal parts (BS) and the crown (C) of two mature Quercus robur L. trees were subjected to rooting experiments to relate rooting with shoot topophysical origin. The BS shoots exhibited morphologically juvenile characteristics and rooted more easily after indole-3-butyric acid (IBA) treatment than C shoots. When naphthylphthalamic acid (NPA) was applied to BS shoots, rooting capacity decreased and root emergence was delayed at least 2 days compared with shoots treated with IBA only. During the first days of the rooting process, endogenous indole-3-acetic acid (IAA) concentration was higher in C shoots than in BS shoots, regardless of whether the shoots were treated with NPA. Mitotic figures were observed in cells from the basal part of both BS and C shoots 24 h after IBA treatment. After 4 days of IBA treatment, the occurrence of histological events differed between BS shoots and C shoots. Cells of BS shoots became meristematic, giving rise to meristemoids and root primordia, whereas no differentiation of root meristemoids occurred in cells of C shoots. Thus, although adult oak material (C shoots) is capable of responding to the initial stimulus of auxin during the adventitious rooting process, the endogenous IAA concentration is not the factor limiting rooting in adult material.