Detecting a leachate plume in an aeolian sand landscape using a DUALEM‐421 induction probe to measure electrical conductivity followed by inversion modelling

Solid waste poses a serious health risk when it is disposed of inadequately because water‐based solutions derived from the decomposition of solid waste products (leachate) can enter groundwater systems via plumes. To assess the public health risk and potential ecological impacts, we require knowledge on the pedological and hydrogeological settings in which waste is disposed. This is particularly the case in coarse textured highly permeable soil. To rapidly collect data, geophysical methods such as direct current (dc) resistivity techniques have been used. Moreover, non‐contact electromagnetic (EM) induction instruments have also been employed. The aim of this research was to demonstrate how the inversion using a 1‐dimensional inversion algorithm with lateral constraints of the apparent electrical conductivity (σ_a) measured in the horizontal coplanar (HCP) and perpendicular co‐planar arrays (PRP) of a DUALEM‐421 EM induction probe can be used to develop a two‐dimensional model of the true electrical conductivity (σ) within a Quaternary aeolian sand in the Tuggerah Soil Landscape southeast of Sydney in Australia. Our results from 2D models of σ accord with estimates of bulk electrical conductivity (σ_b) of a leachate plume and uncontaminated groundwater, the stratigraphy of the Tuggerah soil landscape unit and the depth of sand used to landscape the decommissioned landfill. Further research is needed to determine the origin of the plume and a quasi‐3D modelling approach is applicable.     

First report of white spot syndrome virus in wild crustaceans and mollusks in the Paraíba River,Brazil

The aim of the present study was to investigate the presence of white spot syndrome virus (WSSV) in the Paraíba River, Brazil. Eight sampling sites were established on the bank of the river near water intake areas for the farming of Litopenaeus vannamei. Ten specimens of the shrimp Palaemon pandaliformis and the gastropods Pomacea lineata and Melanoides tuberculatus were collected at each site. Eighty‐one gill fragments from P. pandaliformis, 40 whole individuals of M. tuberculatus and 26 muscle fragments from P. lineata were collected. All samples were stored in microcentrifuge tubes with 95% ethanol (1:10; v:v). Tests were performed at the Potiporã Molecular Analysis Laboratory (state of Rio Grande do Norte, Brazil) for the detection of WSSV using Loop Mediated Isothermal Amplification with the aid of the LAMP WSSV kit (Concepto Azul, Ecuador). Twenty‐nine per cent of P. pandaliformis, 48% of M. tuberculatus and 8% of P. lineata tested positive. The findings demonstrate that WSSV is present in wild crustaceans and mollusks, which may serve as vectors and/or reservoirs of the virus, thereby posing a potential risk to local shrimp farming. This is the first report of WSSV in wild specimens of M. tuberculatus and P. lineata.     

Dissolution rates of hydrated lime,Ca(OH)2 in fresh,oligohaline, mesohaline and euhaline waters and its significance for liming of shrimp culture ponds

This study aimed at assessing the dissolution rates of hydrated lime, Ca(OH)₂ in fresh, oligohaline, mesohaline and euhaline waters and discussing its significance for liming of shrimp culture ponds. Appropriate volumes of seawater and distilled water were mixed to prepare oligohaline (1–4 g/L) and mesohaline waters (4–15 g/L). One gram of analytical grade calcium carbonate, CaCO₃, or one gram of analytical grade calcium hydroxide, Ca(OH)₂, were applied in 10‐L gallons filled with seawater (39.9 g/L), 10.7 g/L, 4.2 g/L and distilled water (0.0 g/L). The final TA of water was significantly higher for Ca(OH)₂ than for CaCO₃ only at salinities 4.2 and 10.7 g/L. It was concluded that hydrated lime, Ca(OH)₂ is a better liming option than agricultural limestone, CaCO₃ for moderately saline, hard and/or buffered waters (?4.5 ≤ Langelier saturation index, LSI ≤ ?0.7). In poorly saline, hard and/or buffered waters (LSI < ?4.5), limestone and lime would increase water TA similarly. Neither limestone nor lime should be applied on highly saline, hard and/or buffered waters (LSI > ?0.7) because a TA decrease is expected.     

Integrating local ecological knowledge,citizen science and long‐term historical data for endangered species conservation: Additional records of angel sharks (Chondrichthyes: Squatinidae) in the Mediterranean Sea

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Biological and ecological aspects of the deep‐water red crab populations inhabiting isolated seamounts to the west of the Azores (Mid‐Atlantic Ridge)

Seamounts are common topographic features in the Mid‐Atlantic Ridge (MAR) including the Azores. However, the knowledge on the ecology of seamounts in this region remains scarce despite needs for assessment and management of seamount resources such as the developing fisheries for deep‐water crabs. We described here for the first time the biological characteristics of an unexploited virgin deep‐water red crab Chaceon affinis population on seamount areas of the MAR to test the hypothesis that its general life history characteristics are similar in different ecosystem types (coastal areas and seamounts) across Macaronesia. We used a randomly stratified design to prospect a layer between 600 and 900 m depth around the summit of two isolated seamounts off the Azores. Results were consistent with the literature information in relation to the patterns of depth distribution, size and sex structure, and reproductive aspects. On the other hand, seamounts showed higher abundances when compared to previously studied coastal areas. Abundance may be also different between seamount areas as a function of the suitable bottom type available and presence of hydrothermal vents. We recommend that the essential habitat of the species should be better mapped identifying vulnerable areas before the development of any fishery.     

Effect of feeding frequency on growth performance,blood metabolites,proximate composition and digestive enzymes of Lebranche mullet (Mugil liza) Juveniles

This study verified the effects of feeding frequency on growth, blood metabolites, digestive enzyme activities (alkaline protease, acid protease, amylase and lipase) and proximate composition of Lebranche mullet juveniles. Fish with initial weight of 13.6 ± 0.7 g were distributed in twelve tanks and fed one, three, five and seven times per day to apparent satiation for 60 days. While the final weight of fish fed only once a day attained just 15.4 ± 0.7 g, those fed five or seven times per day reached 54.0 ± 12.1 and 55.9 ± 6.1 g respectively. The feed consumption also increased at high frequencies, but feed efficiency was higher (76.7 ± 11.7%) when mullets were fed three times per day. In general, increasing feeding frequencies also increased blood content of metabolites (total protein, glucose, triglycerides and cholesterol), possibly due to increased intake and absorption of nutrients. The response of digestive enzymes correlated with feeding efficiency, with higher activity in fish fed three or five times per day. Concerning whole‐body proximate composition, no significant difference was observed in protein, but lipid content increased significantly with feed frequency. Based on growth performance and biochemical responses, we recommend feeding Lebranche mullet juveniles three to five times per day.     

Arbuscular mycorrhizal fungi communities improve the phytochemical quality of strawberry

The application of arbuscular mycorrhizal fungi (AMF) in strawberry cultivation can improve its growth and development. The objective of this study was to evaluate if strawberry plants in the absence and presence of inoculation with AMF communities, obtained from soils collected in reference-sites in the cultivation of this species, differ in their morpho-horticultural performance. Two experiments were carried out: in experiment I (frequency of AMF communities species) the treatments were eight soils containing AMF communities, collected from natural and agricultural ecosystems in reference-sites of strawberry cultivation in southern Brazil, with nine samples per treatment; in experiment II (use of AMF communities in strawberry) the treatments were eight AMF communities and one control (non-mycorrhizal plants), arranged in a completely randomised design, with three replicates. The species Claroideoglomus aff. luteum, C. claroideum, C. etunicatum, Funneliformis mosseae and Glomus sp2 were the most frequent in the studied sites and the morpho-horticultural performance of strawberry plants was improved when plants inoculated with AMF communities. Strawberry plants inoculated with mycorrhizae develop a more profuse root system and fruit anthocyanin content is increased.     

Bacillus spp. Inhibit Edwardsiella tarda Quorum-Sensing and Fish Infection

The disruption of pathogen communication or quorum-sensing (QS) via quorum-quenching (QQ) molecules has been proposed as a promising strategy to fight bacterial infections. Bacillus spp. have recognizable biotechnology applications, namely as probiotic health-promoting agents or as a source of natural antimicrobial molecules, including QQ molecules. This study characterized the QQ potential of 200 Bacillus spp., isolated from the gut of different aquaculture fish species, to suppress fish pathogens QS. Approximately 12% of the tested Bacillus spp. fish isolates (FI). were able to interfere with synthetic QS molecules. Ten isolates were further selected as producers of extracellular QQ-molecules and their QQ capacity was evaluated against the QS of important aquaculture bacterial pathogens, namely Aeromonas spp., Vibrio spp., Photobacterium damselae, Edwardsiela tarda, and Shigella sonnei. The results revealed that A. veronii and E. tarda produce QS molecules that are detectable by the Chr. violaceum biosensor, and which were degraded when exposed to the extracellular extracts of three FI isolates. Moreover, the same isolates, identified as B. subtilis, B. vezelensis, and B. pumilus, significantly reduced the pathogenicity of E. tarda in zebrafish larvae, increasing its survival by 50%. Taken together, these results identified three Bacillus spp. capable of extracellularly quenching aquaculture pathogen communication, and thus become a promising source of bioactive molecules for use in the biocontrol of aquaculture bacterial diseases.