Beryllium natural background concentration and mobility: a reappraisal examining the case of high Be-bearing pyroclastic rocks

Beryllium is widely distributed in soils at low levels, but it can also occur naturally in higher concentrations in a variety of materials exploited for many industrial applications. Beryllium is also one of the most toxic natural elements and is known to be a human carcinogen. A concise account of the literature data on baseline concentrations of Be in soils illustrates the possibility of worldwide presence of areas with a high natural background concentration of Be (up to 300 mg/kg), the crustal abundance of which is generally estimated to be in the range 2–6 mg/kg. Nevertheless, the number of available data is rather limited in comparison with those about other toxic elements such as Pb, Cd and Cr. This has probably caused the choice of low values of concentration level as the reference for the definition of soil contamination: these values are not always realistic and are not applicable to large areas. As a case study, we report and analyse a diffuse, unusually high (up to 80 mg/kg, average approximately 20 mg/kg), natural occurrence of beryllium in loose and poorly consolidated pyroclastic layers related to the Pleistocene activity of the Vico volcano. Additionally, the analysis of Be leachability has been carried out, providing evidence of a not negligible mobility in contrast with the scarce data presented in the literature that usually indicate beryllium as an element with low mobility in oxidising surface environmental conditions. This research marks the beginning of a possible reappraisal of beryllium geochemical behaviour and background levels, providing more realistic reference values for risk assessment and land management.     

The valuation of forest carbon services by Mexican citizens: the case of Guadalajara city and La Primavera biosphere reserve

Adequate demand for, and recognition of, forest carbon services is critical to success of market mechanisms for forestry-based conservation and climate change mitigation. National and voluntary carbon-offsetting schemes are emerging as alternatives to international compliance markets. We developed a choice experiment to explore determinants of local forest carbon-offset valuation. A total of 963 citizens from Guadalajara in Mexico were asked to consider a purchase of voluntary offsets from the neighbouring Biosphere Reserve of La Primavera and from two alternative more distant locations: La Michilía in the state of Durango and El Cielo in Tamaulipas. Surveys were applied in market stall sessions and online using two different sampling methods: the snowball technique and via a market research company. The local La Primavera site attracted higher participation and valuation than the more distant sites. However, groups particularly interested in climate change mitigation or cost may accept cost-efficient options in the distant sites. Mean implicit carbon prices obtained ranged from $6.79 to $15.67/tCO_2eq depending on the surveying methodology and profile of respondents. Survey application mode can significantly affect outcome of the experiment. Values from the market stall sessions were higher than those from the snowball and market research samples obtained online; this may be linked to greater cooperation associated with personal interaction and collective action. In agreement with the literature, we found that valuation of forest carbon offsets is associated with cognitive, ethical, behavioural, geographical and economic factors.     

Larval growth in the estuarine crab Chasmagnathus granulata: the importance of salinity experienced during embryonic development, and the initial larval biomass

The importance of salinity experienced during embryonic development and initial larval biomass on larval growth was studied in the South American estuarine crab Chasmagnathus granulata. Ovigerous females were maintained at three salinities (15, 20, and 32‰) from egg laying to hatching of zoea l. Larvae from all treatments were reared under constant conditions of photoperiod (12∶12), temperature (18°C), and salinity (first instar at 20‰, subsequent instars at 32‰). Biomass was measured as dry weight, carbon, and nitrogen content per individual at egg laying, hatching of zoea l, premoult zoea l, and zoea 4, and in 8-day-old megalopa. From hatching to premoult zoea 4, biomass was higher for larvae from prehatching salinities of 15 and 32‰. There was a significant positive correlation between biomass at hatching and at premoult zoea l and zoea 4. Accumulated biomass during zoeal stages tended to be higher for larvae from broods with higher biomass at hatching, although this trend was not always significant. Zoea 4 either directly metamorphosed to megalopa or moulted to zoea 5, following, respectively, a short or long developmental pathway. The proportion of zoea 4 that followed the long pathway was negatively correlated with biomass of zoeal stages. Biomass at hatching was correlated with biomass of megalopae developed through the short pathway, although it was not correlated with the accumulated biomass at this stage. Megalopae developed through the long pathway (i.e. metamorphosed from zoeae 5) had higher biomass than those from the short pathway. The present results suggest that prehatching salinity and initial egg and larval biomass can be very important for larval growth. Published online: 9 August 2002     

Carbon taxation as a means to incentivize forest and fire management

Environment, Development and Sustainability - Wildland fires are increasingly becoming a major concern for many European countries, affecting ecosystems and societies, and they are expected to...     

Age and growth of Electrona antarctica (Pisces: Myctophidae), the dominant mesopelagic fish of the Southern Ocean

Numerically and in biomass, the lanternfish Electrona antarctica is the dominant fish in the vast pelagic region of the Southern Ocean bounded on the north by the Antarctic Convergence and in the south by the Antarctic continental shelf. It is an important krill predator, and in turn is important in the diets of flighted and swimming seabirds. Further, it is the southernmost and coldest-dwelling representative of the globally distributed fish family Myctophidae. The present study was undertaken to estimate the species' growth rate and average life span, to incorporate the information in a basic energy budget, and to compare the growth of E. antarctica with more northerly confamilials. Fishes were aged using primary growth increments that were resolved on sagittal otoliths using three sequential techniques: thin-section grinding and polishing, etching, and scanning electron microscopy (SEM). Based on increment width (0.8 to 1.2 μm), continuity, and previous studies on confamilials, the microincrements were assumed to be deposited on a daily basis. Montages of SEM photomicrographs were constructed for each sagitta to allow the daily rings to be counted over the entire life span of 31 individuals representing the entire size range of the species. Results suggest a larval stage of 30 to 47 d and a maximum life span of 3.5 yr, with females growing faster than males in the last 1.5 yr of life and reaching a larger maximum size. Construction of a simple energy budget using the best information available suggests that a surplus of energy is available to support the observed growth rates (0.05 to 0.07 mm d⁻¹). The results of the present study contrast markedly with previous estimates of an 8 to 11 yr maximum age for E. antarctica. These results provide important data addressing the ecology and population dynamics of the pelagic Antarctic ecosystem. E. antarctica is the end-member species in the continuum of vertically migrating myctophids that extend from the equator to the polar circle. Its growth rate is consonant with that of all other myctophid species examined using primary growth increments to determine age. The present study, in conjunction with earlier studies, suggests that growth rates of mesopelagic species are far higher than previously thought. Received: 12 September 1997 / Accepted: 25 July 1998     

The bathypelagic Decapoda,Lophogastrida, and Mysida of the eastern Gulf of Mexico

The Earth’s greatest living space is found in the bathypelagic zone of the oceans (depths >1,000 m), yet little research has been dedicated to these ecosystems. The micronekton of the bathypelagic zone in the eastern Gulf of Mexico (EGOM) was investigated with the goal of comparing its community structure with that of the well-studied mesopelagic micronekton. Herein is described a portion of that community, specifically species belonging to the orders Lophogastrida, Mysida, and Decapoda. A total of 46 species were collected, most of which have broad zoogeographic distributions. Seventeen of the species had not previously been collected above 1,000 m in the same location despite over 20 years of sampling. Compared to the mesopelagic zone, the bathypelagic community showed increased contributions to abundance and estimated biomass from the Oplophoridae and Eucopiidae, with a simultaneous decrease in the importance of the Dendrobranchiata. In addition, the bathypelagic zone was distinguished by a relatively high percentage of individuals that brood their eggs (77% vs. 15% in the mesopelagic zone). The results are interpreted as evidence that the bathypelagic zone contains a distinct pelagic community, with a biology and ecology fundamentally different from that of the mesopelagic zone.     

Phylogenetic diversity of epibiotic bacteria in the accessory nidamental glands of squids (Cephalopoda: Loliginidae and Idiosepiidae)

Bacterial communities were identified from the accessory nidamental glands (ANGs) of European and Western Pacific squids of the families Loliginidae and Idiosepiidae, as also in the egg capsules, embryo and yolk of two loliginid squid species, and in the entire egg of one idiosepiid squid species. The results of phylogenetic analyses of 16S RNA gene (rDNA) confirmed that several phylotypes of α-proteobacteria, γ-proteobacteria and Cytophaga–Flavobacteria–Bacteroides phylum were present as potential symbiotic associations within the ANGs. Several identified clones were related to reference strains, while others had no known close relatives. Gram positive strains were rare in loliginid squids. Several bacterial groups may play important roles in the function of the ANGs, such as production of the toxic compounds involved in egg protection and carotenoid pigments. Within the eggs, no bacteria were associated with embryo or yolk of Loligo vulgaris and Sepioteuthis lessoniana, but α- and γ-proteobacteria were present in the egg capsules. Most bacterial strains detected in the egg capsules were the same as those found in the ANGs. The cephalopods of temperate regions (European cuttlefishes and the squid L. vulgaris) appear to be associated with one Agrobacterium strain (Agro2) while tropical-subtropical strains (Asian and Australian loliginids) are associated with Silicibacter-related strains, suggesting a biogeographic clustering for the Agrobacterium-like strains.     

The neglected burden of agricultural intensification: a contribution to the debate on land-use change

ABSTRACT

Between 1992 and 2015 Argentina lost 17% of its tree cover. Regionally, deforestation continues, but net forest loss recently came to a halt. Some scholars argue that this was facilitated by industrial agricultural intensification. This view is debated, but we focus on the neglected costs associated with this intensification. An almost tenfold increase of pesticide use in Argentina during the last two decades caused the pollution of soil, water and sediments. The widespread use of pesticides is impairing the health of agricultural workers and people living near agricultural fields, and is putting the health of vulnerable parts of the population (children and pregnant women) at risk. More than 50 pesticide active ingredients marketed in Argentina have been banned in the European Union for safety reasons. We contend that health and pollution aspects need to be taken into account when assessing the benefits and drawbacks of different types of land use.     

Concentrations of heavy metals in Sotalia fluviatilis (Cetacea: Delphinidae) off the coast of Ceará, northeast Brazil

Lead (Pb), cadmium (Cd) and mercury (Hg) concentrations on liver and kidney of Sotalia fluviatilis (Cetacea: Delphinidae) stranded in the coast of Ceará, Brazil, were studied from 1996 to 1999. Pb levels were usually lower than the detection limit (0.1 microg/g). Concentrations of Cd were significantly higher in kidney than liver, averaging 0.8 microg/g. Mercury accumulation took place mainly in liver with an average concentration of 4.6 microg/g. Both metals were significantly higher in larger mature individuals, but differences between sexes were not significant. The detection of Cd, Hg and Pb in tissue samples of S. fluviatilis off the coast of Ceará indicated that heavy metals are locally available in the water, and bioaccumulation may be occurring through the food web. Contamination levels were not considered critical, but could be related to Ceará's growing industrial development. The associated risks of pollution outfalls may pose a threat to marine organisms in a near future, especially for top predators such as S. fluviatilis.