Perennial phenology patterns and ecological traits of Dixidae (Insecta,Diptera) in lotic habitats of a barrage lake system

Dixidae (Insecta, Diptera) are an interesting ecological component in freshwater ecosystems. They are merolimnic insects with larvae and pupae living in aquatic habitats while adults live in terrestrial habitats in close proximity to water. The goals of this study were to determine the phenology patterns of Dixidae and what influences them, to analyse their preference for microhabitats, and to determine the main ecological factors that have an influence on the composition of Dixidae. Adult Dixidae were collected monthly in the period from 2007 to 2008 at 10 sites, from 2009 to 2010 at four sites, and from 2011 to 2014 at three sites in the Plitvice Lakes National Park. Adult specimens were collected using pyramid-type emergence traps. A total of 1271 Dixidae were collected during eight years of study belonging to five species of the genus Dixa. Dixa submaculata was most abundant species at the spring and upper reach of Bijela rijeka Stream and the upper reach of Crna rijeka Stream. Dixa nebulosa was most numerous at the Kozjak-Milanovac tufa barrier site. Dixa puberula was the dominant species at the rest of the sites. Dixa puberula and Dixa submaculata were univoltine, bivoltine or trivoltine, depending on the site, while Dixa nebulosa was only univoltine. The highest diversity was recorded at the tufa barrier Kozjak-Milanovac, and the highest number of species, four species, was found at the upper reach of the Crna rijeka Stream. The greatest number of specimens was recorded at the Labudovac tufa barrier, 128 specimens in 2014. Water temperature is the main ecological factor that influences the phenology of Dixidae at the tufa barriers and lower streams. Discharge affected the abundance of Dixidae. Dixa puberula prefers moss as a substrate and a faster water velocity.     

Emergence patterns and microhabitat preference of aquatic dance flies (Empididae; Clinocerinae and Hemerodromiinae) on a longitudinal gradient of barrage lake system

Aquatic dance flies (Empididae; Clinocerinae and Hemerodromiinae) are important components of freshwater assemblages, especially in running waters. They are predators as larvae and adults and thus essential for understanding aquatic food webs. This study was conducted in Plitvice lakes National Park (Croatia) representing a wide variety of freshwater habitats (springs, streams, lakes and tufa barriers). Adults were collected monthly from March 2007 until March 2009 using pyramid-type emergence traps at 13 locations. A total of 3865 specimens comprising 18 species were collected. The dominant genus was Chelifera, while the most abundant species was Hemerodromia unilineata. All species were univoltine except Chelifera precabunda, Chelifera pyrenaica and Chelifera stigmatica that were bivoltine. Considerable differences in composition and structure of aquatic dance flies assemblages were recorded along a longitudinal gradient of studied sites, primarily related to differences in physical and chemical parameters of water. Water temperature was the main factor influencing the timing of emergence. Hemerodromia species preferred variable water temperature throughout the year while the majority of the Chelifera species preferred stable water temperature characteristic of spring sites. Furthermore, discharge affected assemblage composition of aquatic dance flies. The highest abundance of aquatic dance flies was recorded in lotic habitats with fast water current over substrates of moss, gravel and particulate tufa with detritus. These results give a new insight on microhabitat preference and their distribution on unique karstic habitats.     

How fast does tufa grow? Very high-resolution measurement of the tufa growth rate on artificial substrates by the development of a contactless image-based modelling device

Accurate determination of the tufa growth rate (TGR) is required to answer the fundamental geomorphological question of tufa evolution. The TGR has been measured by various direct and indirect methods. One of the most popular direct methods uses modified micro-erosion meter (MEM), which has several drawbacks. Here, we present for the first time a coordinate measuring macro-photogrammetry device (CMD) for monitoring the TGR in a contactless manner. The CMD was applied on 28 limestone plates at 14 locations within the Skradinski buk area, Croatia, and measurements were performed in the laboratory. The TGR was derived from digital tufa high-resolution models (DTHRMs). The accuracy of the device was evaluated using state-of-the-art three-dimensional (3D) scanners and error calculation at checkpoints. Moreover, the precision was evaluated with the split test (n = 5). A total of 74 DTHRMs with a spatial resolution of 0.0236 mm were created. The TGR ranged from 0.327 to 19.302 mm a⁻¹, with an average of 5.771 mm a⁻¹. A higher TGR was observed on the limestone plates near mosses, located in fast and turbulent water rather than in stagnant water. We found that specific micro-environmental factors (e.g. proximity to moss) positively affected tufa growth. Erosion events were observed, as well as the presence of aquatic insect larvae (Simuliidae and Chironomidae), which positively affected tufa growth. The CMD is a precise and accurate device that does not suffer from the drawbacks of the MEM method and has many other advantages. It has a high capability of tufa erosion detection, enables the identification of macroinvertebrates, and multispectral or hyperspectral cameras can be mounted on the device for spectral reflectance analysis of the tufa surface. The CMD can be applied in any study requiring a sub-millimetre data quality and involving the comparison of consecutive 3D models and derivation of various parameters of smaller objects. © 2020 John Wiley & Sons, Ltd.     

Small-scale patterns of meiofauna in a bryophyte covered tufa barrier (Plitvice Lakes,Croatia)

Meiobenthic fauna is complex and essential part of the stream benthos and it is known as intermediaries from bacteria to higher trophic levels. However, the dynamics and mechanisms regulating this community at small-scale largely have been neglected. This study was carried out to determine meiofaunal dynamics in a small scale-patterns influenced by flow velocity and other abiotic and biotic factors. We examined meiofauna within bryophytes on a tufa barrier in Plitvice Lakes National Park using a detailed taxonomic approach of various meiofaunal groups and their feeding guilds. We choose three microhabitats (slow, medium, fast) differing significantly in flow velocity above bryophytes. Bdelloid rotifers were the most abundant group in microhabitat with highest flow velocity, while in other two microhabitats nematodes and monogonont rotifers prevailed in abundance. Data on environmental variables and main meiofaunal taxa and feeding guilds were analyzed using redundancy analysis. This analysis indicated that microfilter feeding guild (e.g. bdelloid rotifers) was strongly affected by interaction of flow velocity and POM fractions. Other feeding guilds were influenced by temperature, oxygen and/or pH and did not prefer high flow velocity. Suction-feeder nematodes and microfilter-feeder rotifers were dominant on temporal and spatial scale, indicating their good adaptations on frequently disturbed conditions that prevailed on bryophyte covered tufa barrier. Our results provide comprehensive survey of diversity, density as well as trophic structure of meiofauna in aquatic bryophytes. Differences in meiofaunal composition and density between three microhabitats suggest that the meiofauna is relevant indicator of environmental changes even at small-scale pattern.     

Removal and biodegradation of nonylphenol by different Chlorella species

All four Chlorella species, including one commercially available species, Chlorella vulgaris and three local isolates, Chlorella sp. (1uoai), Chlorella sp. (2f5aia) and Chlorella miniata (WW1), had a rapid and high ability to remove nonylphenol (NP). Among these species, C. vulgaris had the highest NP removal (nearly all NP was removed from the medium) and degradation abilities (more than 80% of NP was degraded) after 168 h, followed by WW1 and 1uoai; 2f5aia had the lowest NP degradation ability. The NP removal by C. vulgaris was less affected by growth conditions, but its biodegradation efficiency was significantly increased by temperature and light intensity, suggesting that the biodegradation ability was positively related to photosynthetic and metabolic activities. These results indicated that C. vulgaris was the most suitable species for effective removal and biodegradation of NP, especially under 25 °C with light illumination and initial biomass between 0.5 and 1.0 mg chlorophyll l⁻¹.     

The response of Clitellata (Annelida) to environmental gradients in spring fens

Patterns in aquatic Clitellata assemblage composition are known to be driven by several environmental gradients, with water chemistry and substratum characteristics being particularly important. In this study we explored 54 isolated spring fens across the eastern Czech Republic and Slovakia. These fens varied in calcium and magnesium concentrations, forming a sharp and well defined environmental gradient running from calcium-poor acidic fens to extremely calcium-rich tufa-forming fens. We found that the main changes in clitellate species composition were controlled by this gradient, and/or total organic carbon content, over a wide area, including fen sites differing in other environmental conditions and historical development. However, this pattern was weakened in sites with a high organic matter content, which represented a second driver of change in assemblage composition along with water temperature. Three main types of fens were determined using cluster analysis based on clitellate assemblage composition. However, only the first type, which included tufa-forming fens, was found to fit with the previously established spring fen types based on vegetation (i.e. extremely mineral-rich fens with a tufa, brown-moss mineral-rich fens, mineral-rich Sphagnum fens and mineral-poor Sphagnum fens). The second clitellate type included sites with low temperatures and occasional desiccation, while the third type was characterised by high temperatures and trophy. Using eight environmental predictors, we were able to significantly explain changes in the population abundances of all 12 common species (i.e. recorded at 15-plus sites). The results from individual species modelling also suggests that an increase in organic matter content can trigger compositional shifts towards assemblages of common eurytopic tubificid species. Thus, human-induced eutrophication and negative changes in spring fen hydrology, mainly drying up, can represent a serious threat for species-specific assemblages of aquatic clitellates, especially at alkaline sites due to their isolated and spatially limited nature.     

Functional Community Organization of Macroinvertebrates in Lotic Habitats of the Plitvice Lakes Funktionelle Organisation der Makroinvertebraten-Gemeinschaft in den lotischen Habitaten der Seen von Plitvice

The community and trophic structure of benthic macroinvertebrates were studied in different types of habitats in the karstic Plitvice Lake system located in the NW Dinarid mountains (Croatia). The spatial distribution of functional macroconsumer groups shows that longitudinal community functional organization doesn't correspond with the River Continuum Concept (RCC) hypothesis. Collector guilds were the most abundant functional feeding groups at all the sites analyzed. The domination of shredders was found only in habitats in the source areas of the supply streams. The disturbed longitudinal community functional organization is caused by a discontinuum in the gradient of physical factors which is a result of the geomorphological origin of travertine barriers along the hydrosystem.     

Cellular energy allocation in mussels (Mytilus galloprovincialis) from the stratified estuary as a physiological biomarker

This study demonstrates the usefulness of cellular energy allocation (CEA) evaluations as a physiological biomarker to infer the occurrence of natural stress in native populations of mussels inhabiting the stratified estuary (Krka River estuary, Croatia). Sampling sites were selected based on their differences in the salinity and temperature. The CEA value was calculated as a ratio between available energy (E_a) and energy consumption (E_c). Generally, higher values of E_a were recorded in June than in November, which were especially evident in the storage components (carbohydrates and lipids), while the constitutive component (proteins) remained relatively constant. The highest E_c was recorded in mussels at estuarine site compared to coastal site, which may be caused by the energetically costly maintenance of osmotic balance. Decrease in CEA recorded in estuarine mussels may ultimately result in a lower amount of energy available for growth, reproduction, or defence against other stresses (e.g. pollution).     

Effects of 4-nonylphenol exposure in mussels (Mytilus galloprovincialis) and crabs (Carcinus aestuarii) with particular emphasis on vitellogenin induction

Since it is often difficult to estimate possible adverse effects due to contamination in selected ecosystems, multi-species biomonitoring may provide more information, taking into account different routes of exposure, ecological roles and metabolic capabilities of animals. In this context, we exposed for 7 days the mussel Mytilus galloprovincialis and the crab Carcinus aestuarii to 4-nonylphenol (NP), a well-known xenoestrogen. In mussels (0–0.2 mg NP l⁻¹), we measured NP bioaccumulation in soft tissues and vitellogenin (Vg)-like protein levels in digestive glands from both males and females by the alkali-labile phosphate assay (ALP). As no reference data were available for crab exposure, the NP 96-h LC₅₀ value was previously determined. Then, in sublethally exposed (0–1.0 mg NP l⁻¹) male crabs, NP bioaccumulation and Vg levels were measured in hemolymph, gonads and digestive gland. Bioaccumulation of NP increased from 43 to 371 μg g⁻¹ d.w. in mussels, and from 3.6 to 37 μg g⁻¹ d.w. in crabs, depending on the NP concentration in water. Dose-dependent Vg-like protein induction was observed in both species, appearing to be related to NP bioaccumulation, although a partial decrease was recorded at the highest concentration tested. A similar trend was observed in both digestive gland and gonad of exposed crabs; Vg increased to a lesser extent, although significantly, in hemolymph. Results demonstrated that NP induces Vg synthesis both in male and female mussels, as well as in male crabs. On the basis of the responsiveness of both species investigated, a multi-species approach is indicated in biomonitoring programmes.     

Eocene biostratigraphy and magnetic stratigraphy from Possagno,Italy: The calcareous nannofossil response to climate variability

A study of quantitative calcareous nannofossil biostratigraphy and magnetostratigraphy of a ∼ 68-m-thick marine limestone section of Late Paleocene–Middle Eocene age outcropping at Possagno in northern Italy shows that the section encompasses nannofossil Zones NP9–NP15 (equivalent to CP8–CP13b) and Chrons C24r–C21n. The Paleocene–Eocene boundary was placed at the base a of δ¹³C negative excursion from the literature that was found virtually coincident with the base of Zone NP9b. The base of the Middle Eocene (Lutetian) was placed at the base of Chron C21r. Biostratigraphic events were generally found to be consistent with parallel events in recent time scales; several potentially useful new events are also described. In particular, we detected the earliest specimens of Dictyococcites at the base of Chron C22r (NP12–NP13 zonal transition), which is several million years older than previous estimates. Correlation of Possagno data to the oxygen isotope record from the literature allowed us to describe the temporal relationships between climate variability and calcareous nannofossil assemblages. Modifications in the nannofossil assemblage coeval to both the Paleocene–Eocene Thermal Maximum (PETM) and the Early–Middle Eocene long-term climatic trend are recognized. The short-lived PETM was coeval to provisional adaptations (malformations and/or ecophenotypes) in the coccolithophores communities that were reabsorbed upon return to long-term varying climatic conditions. The Early–Middle Eocene long-term climatic trend was instead coeval to true evolutionary trends with the appearance of the very successful Noelaerhabdaceae clade whose offsprings include the most important bloom-forming coccolithophorids in the modern ocean. The Early–Middle Eocene can thus be considered the time in which nannoplankton communities set course toward modern structure triggering a reconfiguration of the global ocean life chain.     

In vitro effects of nonylphenol on functional responses of haemocytes of the colonial ascidian Botryllus schlosseri

The effects of nonylphenol (NP) on functional responses of haemocytes of the colonial ascidian Botryllus schlosseri were evaluated. Haemocytes were exposed to 0.1, 1 and 10 μM NP and the effects on haemocyte viability, adhesion, morphology, lysosomal membrane stability, phagocytic activity and early apoptosis were evaluated. Haemocyte viability and adhesion were not affected by NP. Phagocytic activity and the amoebocytic index decreased significantly at all the concentrations tested, while exposure of haemocytes to 1 and 10 μM NP caused a significant increase in the diffusion of Neutral Red into the cytosol. The percentage of cells positive to Annexin-V (indicative of early apoptosis) increased significantly at 1 and 10 μM NP. Results obtained suggested a relationship between NP and alterations in functional responses of haemocytes in B. schlosseri. Biomarkers measured resulted sensitive, rapid and reproducible, even if their responsiveness will be evaluated after in vivo exposure of animals to NP.     

Field and large scale laboratory studies on dynamic properties of emplaced municipal solid waste from two dump sites at Delhi,India

Dynamic properties of municipal solid waste (MSW) from two dump sites located at Delhi, India are evaluated from field and large scale laboratory tests. Shear wave velocity (V_s) profiles of MSW, measured at these two sites using surface wave techniques, are in range of V_s data reported for MSW landfills worldwide. Representative bulk MSW samples were collected from large test pits excavated at the two dump sites to determine the near surface unit weight. Large scale undrained cyclic triaxial (CTX) tests were conducted on reconstituted MSW specimens to investigate the effect of various parameters such as composition, confining pressure, number of loading cycles, loading frequency and saturation on the dynamic properties. Undrained CTX tests, conducted on the specimens with and without fibrous materials demonstrated the effect of fibrous waste constituents on the stiffness and damping behavior of MSW. Specimens consisting of fibrous waste constituents such as plastics and textiles exhibited significantly less modulus reduction compared to specimens with negligible amount of fibrous content. The modulus reduction (G/G_max) and material damping ratio curves derived from the present study are in the range reported for MSW in the literature. The G/G_max curves from present study are in good agreement with curves recommended for MSW at Tri-Cities landfill in USA and Tianziling landfill in China. Dynamic properties evaluated from the present study add to the growing database of the worldwide dataset and can be useful for evaluating the seismic stability and associated permanent deformations of the existing dumps in and around Delhi.     

The influence of diurnal temperatures on the hydrochemistry of a tufa‐depositing stream

At‐a‐station diurnal variations in carbonate hydrochemistry were measured during four observation periods at Davys Creek, a tufa‐depositing stream in central NSW, Australia. Major ion concentrations and continuously logged measurements of specific conductivity, pH and temperature showed that changes in the amount of CaCO₃ deposited upstream of the study reach were directly related to changes in diurnal water temperatures, which control the rate of CO₂ efflux to the atmosphere. The greatest upstream losses occurred during the mid‐afternoon water temperature peak, whereas the lowest upstream losses occurred at sunrise, when water temperatures were at their lowest. Cloudy days at all times of the year produced small diurnal water temperatures ranges (c. 2–5°C) and, consequently, relatively small changes in upstream CaCO₃ loss (23–50 mg L^?1) through the day. Clear sunny days, especially during summer months, produced large diurnal water temperature changes (up to c. 11°C), which in turn triggered diurnal changes in upstream CaCO₃ loss of up to 100 mg L^?1. By implication, the active reach of tufa deposition must advance downstream and increase in length during the evening and vice versa during the day. Given that the temperature of Davys Creek waters are a function of insolation, changes in the reach of tufa deposition under baseflow conditions are a direct function of the prevailing weather. This has implications for the palaeoclimatic interpretation of fossil tufa deposits. Copyright © 2003 John Wiley & Sons, Ltd.     

The role of gypsum and/or dolomite dissolution in tufa precipitation: lessons from the hydrochemistry of a carbonate–sulphate karst system

The precipitation of freshwater carbonates (tufa) along karstic rivers is enhanced by degassing of carbon dioxide (CO₂) downstream of karstic springs. However, in most karstic springs CO₂ degassing is not enough to force the precipitation of tufa sediments. Little is known about the role of dissolution of gypsum or dolomite in the hydrochemistry of these systems and how this affects the formation of tufa deposits. Here we present a monitoring study conducted over a year in Trabaque River (Spain). The river has typical karst hydrological dynamics with water sinking upstream and re‐emerging downstream of the canyon. Mixing of calcium–magnesium bicarbonate and calcium sulphate waters downstream of the sink enhances the dissolution of carbonates and potentially plays a positive role in the formation of tufa sediments. However, due to the common‐ion effect, dissolution of dolomite and/or gypsum causes precipitation of underground calcite cements as part of the incongruent dissolution of dolomite/dedolomitization process, which limits the precipitation of tufa sediments. Current precipitation of tufa is scant compared to previous Holocene tufa deposits, which likely precipitated from solutions with higher saturation indexes of calcite (SIcc values) than nowadays. Limited incongruent dissolution of dolomite/dedolomitization favours higher SIcc values. This circumstance occurs when waters with relatively high supersaturation of dolomite and low SO₄^2? composition sink in the upper sector of the canyon. In such a scenario, the process of mixing waters enhances the exclusive dissolution of limestones, preventing the precipitation of calcite within the aquifer and favouring the increase of SIcc values downstream of the springs. Such conditions were recorded during periods of high water level of the aquifers and during floods. This research shows that the common‐ion effect caused by the dissolution of gypsum and/or dolomite rocks can limit [or favour] the precipitation of tufa sediments depending on the occurrence [or not] of incongruent dissolution of dolomite/dedolomitization. Copyright © 2016 John Wiley & Sons, Ltd.     

Climatic and tectonic significance of Late Pleistocene and Holocene tufa deposits in the Mijares River canyon,eastern Iberian Range,northeast Spain

The tufa deposits developed in the Mijares River canyon at the eastern sector of the Iberian Range were studied by using geomorphological, stratigraphic, micromorphological, mineralogical and chronological (U/Th and ¹⁴C) techniques. These tufas are located along a high‐gradient river profile reach, with high water turbulence and mechanical outgassing, related to Quaternary faulting activity upstream in the regional context of an extensional tectonic regime. Two stepped and terraced fluviatile tufa structures with large phytohermal barrage frameworks and smaller dammed areas have been differentiated. The first structure, Upper Pleistocene in age (from 200 000 to 50 000 years BP ), is made up by two morphosedimentary units reaching 120 m in thickness, and the second one, Holocene in age (10 000–5000 years BP ), is 35 m in thickness. These structures record a more or less continuous tufa development with a mean deposition rate ranging between 1 and 5 mm a⁻¹ as minimum. A preferential growth with high biological activity during warm and wet palaeoenvironmental stages (isotopic stages 7, 3 and 1) can be deduced. Thus, neotectonic activity controlled the location along the Mijares River as well as the large thickness of the tufa deposits, whereas warm climatic periods favoured intense tufa activity in the fluvial system. Copyright © 2000 John Wiley & Sons, Ltd.     

Eine neue elektrochemische Methode zur Bestimmung von Bromidionen in natürlichen Gewässern

A New Electrochemical Method for the Determination of Bromide in Natural Waters Formation of poorly soluble Hg(I)-halides at the polarized mercury electrode was used for the development of a new electrochemical method for determination of bromide in mixed chloride and bromide solutions. Interferences due to anions, surface-active agents, and suspended matter present in natural waters were not found. The applicability of the method to natural waters was tested in the Krka River estuary in Croatia. The mass ratio Br/chlorinity = 3.320·10^?3 was calculated on the basis of recorded bromide concentrations in the estuary. As the relationship is linear, conservative behaviour of bromide ions in the Krka River estuary may be assumed.     

ESR/U-series dating of Eemian human occupations of Northern France

Palaeolithic sites associated with the Eemian Interglacial (MIS 5e) are very rare in NW Europe, and especially in Northern France, where their preservation is restricted to very specific geological contexts, in association with carbonated tufa (Caours) or peat deposits (Waziers). In order to check the reliability of ESR/U-series method to date teeth recovered from archaeological levels in such specific geological environments, teeth were sampled on these two Middle Palaeolithic sites and systematic in situ dosimetry was performed using portable gamma spectrometer. The ESR/U-series ages obtained on the Caours site are very homogeneous allowing the calculation of a mean age equal to 125 ± 11 ka, in agreement with the geological age, mammal's association and other available geochronological data (U-series on tufa carbonate, TL on burnt flints, OSL on sediments), despite a relatively heterogeneous dosimetric environment (gamma dose rate ranging between ca 200–450 μGy/a). At Waziers, reducing (water logging) environment linked to the peat leads to very specific U-series data of the analysed teeth (U content lower than 0.1 ppm in all the dental tissues, evidence of leaching in some tissues), but the mean ESR/U-series age, 129 ± 4 ka, is also in agreement with the available geological and palaeoenvironmental data indicating that the dated teeth were associated with Late Glacial deposits prior to the climatic interglacial optimum. These two case studies then confirm the reliability of ESR/U-series method to date with good reliability and accuracy the archaeological levels linked to such relatively short climatic events (ca 10 ka).     

Large-scale seagrass restoration in a damaged estuary

After several years of environmental planning, and the Port of Miami Expansion Program having been started, a large-scale seagrass restoration project, including a test plot programme, was initiated in a damaged estuary in south-eastern Florida, Biscayne Bay, in 1982. For the project 13 test plots throughout the area were selected, totalling 10.38 acres in area, which is the largest test plot programme implemented to date, with the exception of our ongoing test plot programme in Jamaica (16.9 acres). Three seagrasses, Thalassia testudinum, Halodule wrightii and Syringodium filiforme, were transplanted at each test plot by two methods: 9.4–18.6 months after transplantation, survival and growth of the plants were measured (survival measurements taken by Connell Associates, Inc., 1983). Thalassia sprigs ranked first in survival followed by Halodule sprigs.Test plots differed widely in the survival and growth of the three species. Nine of the 13 plots had one species/method successful enough for further planting. Mid-bay sites damaged by dredging had two species surviving 60% or more. High turbidity sites were the least successful. Only Thalassia sprigs were successful at high energy sites. Syringodium sprigs showed poor survival overall, and are not recommended for transplanting. Thalassia seedlings appeared adequate in low energy sites, but required heavier anchoring in medium energy sites. The major impacts to the test plots were dredging, filling and urban run-off. No industrial effluent sites were included.     

Lethal and estrogenic effects of 4-nonylphenol in the cockle Cerastoderma glaucum

The lethal and sublethal effects of the xenoestrogen 4-nonylphenol (NP) were evaluated in the cockle Cerastoderma glaucum. In a 96-h lethality test, bivalves were exposed to 0, 0+ acetone, 0.19, 0.38, 0.75, 1.5 and 3.0 mg NP/l. The 96-h LC₅₀ value was 0.3 mg NP/l. No mortality was observed at 0.1 mg NP/l. The potential estrogenicity of NP was studied in both sexually undifferentiated (resting phase) and differentiated (pre-spawning phase) cockles, exposed for 7 and 14 days to 0, 0+ acetone, 0.0125, 0.025, 0.05, and 0.1 mg NP/l. Vitellogenin (Vg)-like protein levels were determined in both haemolymph and digestive gland by the alkali-labile phosphate (ALP) assay. In the resting phase, exposure for 7 days to 0.1 mg NP/l resulted in significant increases in ALP in both haemolymph and digestive gland, compared with controls. A significant increase was also observed in digestive gland of animals exposed to 0.0125 mg NP/l-exposed animals. After 14 days of exposure, haemolymph ALP levels were significantly increased in exposed animals at all NP concentrations tested, whereas no difference was recorded in digestive gland. In the pre-spawning phase, exposure for 7 days to NP significantly increased ALP levels in haemolymph from males exposed at all NP concentrations tested, whereas no significant variations were found in haemolymph from females. NP (0.05 and 0.1 mg/l) was also shown to increase ALP concentrations significantly in digestive gland of males, but not in those of females. Likewise, after 14 days’ exposure, ALP levels significantly increased in haemolymph from males only at 0.1 mg NP/l. Conversely, NP caused significant increases in ALP levels in digestive gland from both males (at all NP concentrations tested) and females (at 0.025 and 0.1 mg NP/l). These results demonstrate that NP induces Vg synthesis in C. glaucum. Interestingly, males were more responsive to NP than females.     

In situ cosmogenic nuclide production rate calibration for the CRONUS-Earth project from Lake Bonneville,Utah, shoreline features

Well-dated bedrock surfaces associated with the highstand and subsequent catastrophic draining of Pleistocene Lake Bonneville, Utah, during the Bonneville flood are excellent locations for in situ cosmogenic nuclide production rate calibration. The CRONUS-Earth project sampled wave-polished bedrock and boulders on an extensive wave-cut bench formed during the Bonneville-level highstand that was abandoned almost instantaneously during the Bonneville flood. CRONUS-Earth also sampled the Tabernacle Hill basalt flow that erupted into Lake Bonneville soon after its stabilization at the Provo level, following the flood. New radiocarbon dating results from tufa at the margins of Tabernacle Hill as part of this study have solidified key aspects of the exposure history at both sites. Both sites have well-constrained exposure histories in which factors such as potential prior exposure, erosion, and shielding are either demonstrably negligible or quantifiable. Multi-nuclide analyses from multiple labs serve as an ad hoc inter-laboratory comparison that supplements and expands on the formalized CRONUS-Earth and CRONUS-EU inter-laboratory comparisons (Blard et al., 2015; Jull et al., 2015; Vermeesch et al., 2015). Results from ¹⁰Be, ²⁶Al, and ¹⁴C all exhibit scatter comparable to that observed in the CRONUS-Earth effort. Although a ³⁶Cl inter-laboratory comparison was not completed for Jull et al. (2015), ³⁶Cl from plagioclase mineral separates exhibits comparable reproducibility. Site production rates derived from these measurements provide valuable input to the global production rate calibration described by Borchers et al. (2015). Whole-rock ³⁶Cl concentrations, however, exhibit inter-laboratory variation exceeding analytical uncertainty and outside the ranges observed for the other nuclides (Jull et al., 2015). A rigorous inter-laboratory comparison studying the systematics of whole-rock ³⁶Cl extraction techniques is currently underway with the goals of delineating the source(s) of this discrepancy and standardizing these procedures going forward.