Minerals and Waste

A novel bacterial disease of the European shore crab, Carcinus maenas -molecular pathology and epidemiology Several rickettsia-like diseases have been reported in arthropods (insects and crustaceans), some of which result in significant losses of economically important species such as shrimp and crabs. This study reports on the molecular pathology of a recently emerged disease of the European shore crab, Carcinus maenas, termed milky disease -named as a result of the unusual milky appearance of the haemolymph (blood). This disease was more prevalent (.26 %) during summer months when the water temperature in a pilot crab farm was approximately 19 6C. The putative causative agent of the disease was a Gram-negative bacterium that could not be cultured on a range of agar-based growth media. Diseased crabs showed significant reductions in free blood cell numbers and total serum protein. Such animals also displayed raised levels of glucose and ammonium in blood. Ultrastructural and in situ hybridization studies revealed that the causative agent associated with milky disease multiplied in the fixed phagocytes of the hepatopancreas (digestive gland), ultimately to be released into the haemolymph, where the circulating blood cells showed little response to the presence of these agents. Attempts to induce the infection by short-term temperature stress failed, as did transmission experiments where healthy crabs were fed infected tissues from milky disease affected individuals. Sequence analysis of the 16S rRNA gene from the milky disease bacteria indicated that they are a previously undescribed species of a-proteobacteria with little phylogenetic similarity to members of the order Rickettsiales.

This study represents the first analysis of ammonia removal and bacterial communities in gravel biofilters treating saline wastewater and is of relevance to the growing inland marine aquaculture industry. As part of a study to gain greater understanding of the microbial processes occurring in a newly constructed limestone gravel wetland at a commercial marine fish farm, this study was designed to establish the ammonia removal capacity of model biofilters treating saline aquaculture wastewater and to investigate changes to total bacterial communities and ammonia-oxidizing bacterial communities as the biofilters are exposed to increasing ammonia concentrations. Three replicate laboratory-scale gravel biofilters were constructed and the limits of nitrification capacity were tested by dosing with aquaculture wastewater supplemented with increasing amounts of ammonium chloride. The experiment was run over a 12-week period with the water temperature between 24.5 and 28 • C and salinity between 28 and 38 ppt. Greater than 97% ammonia removal in each weekly treatment period was observed with ammonia concentrations of up to 600 ppm. At higher concentrations of ammonia, a lower percentage of ammonia was removed, and on occasion nitrite accumulation was observed. A drop in the number of operational taxonomic units (OTUs) detected in the bacterial community as measured by 16s rRNA T-RFLP was observed concurrent with the decrease in percentage ammonia removal. T-RFLP of the amoA gene showed the experimental biofilters to be dominated by three different OTUs of ammonia-oxidizing bacteria. A synchronous successional pattern among these three ammonia oxidizers was observed. The three OTUs were identified as belonging to three different nitrosomonad clusters. This study demonstrates that the vertical flow gravel biofilters have the ability to treat saline aquaculture wastewater that has a high ammonia concentration and that the microbial community within saline biofilters has the capacity to adapt to changing ammonia levels while maintaining nitrification activity.

Aims:  The objective of the work was to determine whether known strains of nonpathogenic vibrios can act as probiotics for the control of Vibrio infections in the Pacific white shrimp, Litopenaeus vannamei.Methods and Results:  Of the ten species tested, only Vibrio alginolyticus (NCIMB 1339) and Vibrio gazogenes (NCIMB 2250) showed antagonistic activity towards a panel of shrimp pathogenic vibrios. In the case of V. alginolyticus, this activity depended on the presence of live bacteria while in V. gazogenes both live and dead bacteria showed anti-Vibrio activity. Injection of shrimp with either V. alginolyticus or V. gazogenes at 3 × 107 or 3 × 105 total bacteria per shrimp resulted in mortality with higher levels in the case of V. alginolyticus (100% mortality 18 h postinjection of 3 × 107 bacteria). Juvenile shrimp were fed commercial diets top-coated with either chitin (an immune stimulant) or chitin + V. gazogenes. Both chitin and V. gazogenes caused a significant decline in the number of Vibrio-like bacteria in the fore and hind gut, and changes were also seen in the hepatosomatic index (a measure of digestive health) and the total number of blood cells in circulation. Analysis of mid/hindgut and faecal samples obtained using terminal restriction fragment length polymorphism showed that the gut microbiota of shrimp has limited bacterial diversity and that after 8 weeks exposure to the experimental diets there were significant changes in the microbial flora of the GI tract of shrimp as a result of the presence of V. gazogenes.Conclusions:  Of the vibrios tested, V. gazogenes has potential as a probiotic for the control of bacterial diseases in shrimp.Significance and Impact of the Study:  Overall, this study shows the promise of V. gazogenes together with chitin to improve the health and welfare of shrimp under aquaculture conditions.

Sixteen hundred stream sediments (<150 μm fraction) collected during regional geochemical surveys in central and SW Nigeria have high median and maximum concentrations of Zr that exceed corresponding Zr concentrations found in stream sediments collected from elsewhere in the World with similar bedrock geology. X-ray diffraction studies on a sub-set of the analysed stream sediments showed that Zr is predominantly found in detrital zircon grains. However, the main proximal source rocks (Pan-African 'Older Granites' of Nigeria and their Proterozoic migmatitic gneiss country rocks) are not enriched in zircon (or Zr). Nevertheless, U-Pb LA-ICP-MS dating with cathodoluminescence imaging on detrital zircons, both from stream sediment samples and underlying Pan-African 'Older Granites' confirms a local bedrock source for the stream sediment zircons. A combination of tropical/chemical weathering and continuous physical weathering, both by 'wet season' flash flooding and 'dry season' unidirectional winds are interpreted to have effectively broken down bedrock silicate minerals and removed much of the resultant clay phases, thereby increasing the Zr contents in stream sediments. The strong correlation between winnowing index (Th/Al) and Zr concentration across the study area support this interpretation. Therefore, 'anomalous' high values of Zr, as well as other elements concentrated in resistant 'heavy' minerals in Nigeria's streams may not reflect proximal bedrock concentrations of these elements. This conclusion has important implications for using stream sediment chemistry as an exploration tool in Nigeria for primary metal deposits associated with heavy minerals.

Earth scientists are often asked to establish or constrain the likely provenance of very small quantities of earth-related material as part of a forensic investigation. We tested the independent and collective interpretations of four experts with differing analytical skills in the prediction of sample provenance for three samples from different environmental settings. The methods used were X-ray diffraction, scanning electron microscopy, the assessment of pollen assemblages, and structural characterization of organic matter at the molecular level. Independent interpretations were less accurate than those where multiple techniques were combined. Collective interpretation was very effective in the assessment of provenance for two of the three sites where the mineralogy and plant communities were distinctive. At the other site, although the mineralogical analysis correctly identified the Triassic mudstone soil parent material, Carboniferous spores from domestic coal were initially interpreted as deriving directly from bedrock. Such an interpretation could be a common pitfall owing to anthropogenic redistribution of material such as coal.

Sixteen hundred stream sediments (<150 μm fraction) collected during regional geochemical surveys in central and SW Nigeria have high median and maximum concentrations of Zr that exceed corresponding Zr concentrations found in stream sediments collected from elsewhere in the World with similar bedrock geology. X-ray diffraction studies on a sub-set of the analysed stream sediments showed that Zr is predominantly found in detrital zircon grains. However, the main proximal source rocks (Pan-African 'Older Granites' of Nigeria and their Proterozoic migmatitic gneiss country rocks) are not enriched in zircon (or Zr). Nevertheless, U-Pb LA-ICP-MS dating with cathodoluminescence imaging on detrital zircons, both from stream sediment samples and underlying Pan-African 'Older Granites' confirms a local bedrock source for the stream sediment zircons. A combination of tropical/chemical weathering and continuous physical weathering, both by 'wet season' flash flooding and 'dry season' unidirectional winds are interpreted to have effectively broken down bedrock silicate minerals and removed much of the resultant clay phases, thereby increasing the Zr contents in stream sediments. The strong correlation between winnowing index (Th/Al) and Zr concentration across the study area support this interpretation. Therefore, 'anomalous' high values of Zr, as well as other elements concentrated in resistant 'heavy' minerals in Nigeria's streams may not reflect proximal bedrock concentrations of these elements. This conclusion has important implications for using stream sediment chemistry as an exploration tool in Nigeria for primary metal deposits associated with heavy minerals.

The contribution of individual grain size fractions (2000-500, 500-250, 250-63, 63-2 and <2 m) to bulk soil surface area and reactivity is discussed with reference to mineralogical and oxalate and dithionite extractions data. The 63-2 m fraction contributed up to 56 and 67% of bulk soil volume and BET surface area respectively. Consideration of these observations and the mineralogy of this fraction suggest that the 63-2 m fraction may be the most influential for release of elements via mineral dissolution in the bulk soil.

Urban canal sediment provides an opportunity to investigate the processes controlling P geochemistry in a system dominated by anthropogenic input. To achieve this a combined study was undertaken of pore water geochemistry and petrology of the top 25 cm canal bed sediment from two urban canals in the English West Midland conurbation. Processes in the sediment are dominated by the geochemistry of Fe, P and organic matter. Results indicate that sediment re-suspension by boat traffic has a major influence on pore water chemistry. In addition to the sediment water interface an additional interface at 6-7 cm depth was identified and corresponds to the maximum depth of sediment resuspension by boat traffic. Phosphorus in the sediment occurs predominantly as vivianite. Low PO 4 concentrations occur close to the sediment water interface in summer due to frequent re-suspension and Fe oxidation. High PO 4 concentrations occur close to the sediment water interface in winter when boat traffic is infrequent. The greatest potential to exchange phosphate between sediment and water column will therefore occur during infrequent boat traffic regimes. #

A series of boreholes in Horton Quarry, northwest Yorkshire (Horton-in-Ribblesdale Inlier) penetrated mudstones and slates belonging to the Austwick Formation (Windermere Supergroup) overlying laminated mudstones of the Ingleton Group. Illite (IC) and chlorite (ChC) crystallinity measurements indicate a metamorphic inversion between the two groups of mudrocks. The Windermere Supergroup mudrocks are mostly in the high anchizone or epizone, whereas the Ingletonian samples are lower grade in terms of IC, and are mostly deep diagenetic zone or low anchizone. Hence younger strata at higher grades rest on older strata at lower grades, creating a metamorphic inversion. Ingletonian slates exposed at Pecca Falls on the River Twiss show epizonal and anchizonal IC values, and greywacke samples from Ingleton Quarry contain pumpellyite. This suggests that grade in the Ingletonian may increase to the NW from the Horton to Ingleton inliers. K-white mica b cell dimensions show further differences between the Ingleton Group and the Windermere Supergroup. The Ingletonian samples are characterized by low b cell values (8.989-9.035, mean 9.007 Å ), whereas the Windermere Supergroup has higher values in the range 9.022-9.034, mean 9.027 Å . The Windermere Supergroup values are similar to those recorded from the Windermere Supergroup of the southern Lake District, and Lower Palaeozoic rocks from the Scottish Southern Uplands, and are consistent with metamorphism in a low heat flow, convergent geotectonic setting. The Ingletonian b cell values suggest metamorphism in a higher heat flow setting, most likely an extensional basin. The metamorphic inversion at Horton and differences in K-white mica b cell dimensions suggest that the Ingleton Group and Windermere Supergroup strata evolved in different geotectonic settings and record two separate metamorphic events. The discovery of the metamorphic inversion at Horton provides further evidence in favour of an Ordovician rather than Neoproterozoic depositional age for the controversial Ingleton Group.

The application of sequential extraction procedures to determine metal speciation in sediments is fraught with uncertainty regarding what is actually dissolving or re-precipitating at each stage. In order to choose an appropriate scheme for the investigation of contaminated anaerobic mud two different sequential extraction procedures (Kersten and Förstner, 1986; Quevauviller, 1998) were investigated using a Cryogenic SEM (CryoSEM) technique coupled

The Cyprus Natural Analogue Project was carried out due to the requirement to support ongoing laboratory and modelling efforts on the potential reaction of the bentonite buffer with cementitious leachates in the repository engineered barrier system. Although it is known that the higher pH (12.5À13) leachates from ordinary Portland cement will degrade bentonite, it is unclear if this will also be the case for the lower pH (10À11) leachates typical of low alkali cements. Ongoing laboratory and underground rock laboratory programmes, which are currently investigating this, face the obstacle of slow kinetics and the production of short-lived metastable phases, meaning obtaining unambiguous results may take decades. It was therefore decided to implement a focussed natural analogue study on bentonite/low alkali cement leachate reactions to provide indications of the probable long-term reaction products and reaction pathways to provide feedback on the existing short-term investigations noted above and to ascertain if any critical path research and development needs to be instigated now. The results of the analyses presented here, in this short overview of the project, suggest that there has been very limited alkaline groundwater reaction with the bentonite. This is generally supported by both the geomorphological evidence and the natural decay series data which imply groundwater/rock interaction in the last 10 5 a.

Surface area-normalised dissolution rates of the primary minerals in two distinct granitic soils located in 1) the Dartmoor National Park, England and 2) Glen Dye, Scotland were determined as a function of depth. Each soil was sampled to a depth of~1 m. The maximum soil ages based on 14 C analysis of the humin fraction of the soil are 15,600 and 4400 years for the Dartmoor and Glen Dye soil profiles, respectively. The measured BET surface areas of the soil minerals are close to 5 m 2 /g in the B and C horizons, but decrease to less than 1 m 2 /g close to the surface. Retrieved geometric surface area normalised mineral dissolution rates are most rapid at the surface and at the bedrock-soil interface; this behaviour is interpreted to stem from a combination of the approach to equilibrium of the soil waters with depth and more rapid dissolution rates of fresh versus weathered surfaces. At the soil surface, the relative mineral dissolution rate order is found to be quartz N feldspar N mica, with quartz geometric surface area dissolution rates as fast as 2.6 to 4.1 × 10 −13 mol/m 2 /s. As observed in a number of past studies, field based rates obtained in this study are significantly slower than corresponding rates obtained from laboratory studies, suggesting that these latter rates may not accurately describe the reactivity of primary minerals in soils. Geoderma j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / g e o d e r m a overcome this knowledge gap by determining the dissolution rates of the major silicate minerals in two distinct granitic soils as a function of depth.

During the underground storage of carbon dioxide (CO 2 ) in deep saline formations, the containment of CO 2 will be crucially dependent on the integrity of seals above the CO 2 . These seals could be natural (e.g. a clay-rich caprock) or man-made (e.g. the engineered seals around a borehole). It is important therefore, to assess how the CO 2 might impact these seals, as this could ultimately control the longevity of CO 2 storage. We have undertaken a long-term experimental study focused on the geochemical reactions between CO 2 , synthetic porewaters and caprock material from the Sleipner field.