Density,size structure and aspergillosis prevalence in <Emphasis Type="Italic">Gorgonia ventalina</Emphasis> at six localities in Puerto Rico

Gorgonia ventalina’s density, size structure and lesion prevalence was measured at six sites in Puerto Rico that exhibited variation in horizontal water transparency, sedimentation rates, suspended particle matter, scleractinian and macroalgal cover. G. ventalina density varied significantly among sites (between 0.84 and 0.007 colonies/m²), and was positively correlated with water transparency. Size structure did not vary much among sites, and reflects high mortality among the smaller size classes and high survivorship in large colonies. Prevalence of active fungi-induced lesions (type I) did not vary significantly among sites and was density-independent. However, prevalence of old lesions of unknown origin (type II) did vary among reefs and was negatively correlated with water transparency. Prevalence of types I or II lesions was independent of colony size. Our results suggest that (1) turbidity and sedimentation are important abiotic factors controlling the abundance of sea fans, (2) variation in settlement success and early survivorship of recruits has more impact on the sea fan populations than variation in the survivorship of large colonies and (3) prevalence of aspergillosis (type I) at the studied sites is similar to that reported for other Caribbean reefs and supports the epizootic nature of the disease and (4) lesions with exposed skeleton are more likely to be colonized by fouling organisms at impacted reefs. The combined effects of anthropogenic impacts and aspergillosis may cause local extinctions of sea fans, as is becoming evident in many reefs in Puerto Rico.     

Physiological capacity and environmental tolerance in two sandhopper species with contrasting geographical ranges: Talitrus saltator and Talorchestia ugolinii

We investigated the physiological plasticity and environmental tolerance of two phylogenetically closely related, ecologically similar and co-occurring species of supralittoral amphipods differing drastically in the size of their geographical ranges. A series of physiological traits were characterised for the Corsican-endemic Talorchestia ugolinii Bella-Santini and Ruffo and the widespread Talitrus saltator Montagu. The effect of body mass, temperature and salinity on heart rate (used as proxy for metabolic activity and stress), the effect of temperature on oxygen consumption and the tolerance to salinity exposure were investigated in both species, together with the characterisation of haemolymph osmoregulation in T. ugolinii. Our results showed that there is a clear difference in the resting metabolic rates and physiological capacity, as well as environmental tolerance, between T. saltator and T. ugolinii, with T. saltator overall showing a broader physiological niche. Although T. ugolinii showed a relatively good ability to regulate its haemolymph osmotic concentration (similar to that previously described for T. saltator), it demonstrated a lower tolerance to exposure to hypo-osmotic stress. In addition, a consistent picture emerged between the ability to control the cardiac function and the capacity to actively respond to osmotic stress. The physiological findings are discussed in relation to the known ecology and geographical distribution of T. ugolinii.     

Influence of air pollution on the incidence of respiratory tract neoplasm

To evaluate the possible influence of air pollutants on the incidence of respiratory tract neoplasm we studied 12 S?o Paulo City districts where air pollution is observed. We collected data on pollutants from 1981-1990 and correlated it with the incidence of larynx and lung neoplasms in 1997. Ozone was the pollutant that best correlated with the incidence of neoplasm. The correlation coefficients were 0.7234 (p=0.277) and 0.9929 (p=0.007) for lung and larynx cancer, respectively. There may be a relationship between air pollution and the incidence of respiratory tract neoplasm. This study, however, does not allow us to conclude that there is a causal relationship.     

Mechanism of complexation of toxic arsenate,selenate, and molybdate with hydrotalcites

Environmental Chemistry Letters - Wastewater from the uranium mining industry contains toxic arsenate (AsO43–), selenate (SeO42–), and molybdate (MoO42–) that can be removed by...     

Estimation of chemical concentration due to fugitive emissions during chemical process design

Fugitive emissions are not an environmental concern alone, but are also a health concern. From occupational health standpoint, fugitive emissions are the main sources of origin of the continuous exposure to workers. Operating plants regularly measure release and concentration levels through a plant-monitoring program. However, for processes which are still ‘on paper’, predictive estimation methods are required. Therefore, three methods for estimating concentration of the fugitive emissions are presented for the process development and design phases of petrochemical processes. The methods estimate the fugitive emission rates and plant plot dimensions resulting to fugitive emission concentrations. The methods were developed for the type and amount of information available in three process design stages; conceptual design, preliminary process design, and detailed process design. The methods are applied on a real benzene plant; the estimated benzene concentrations are compared to the actual concentration measured at the plant. The results show that as the information mounts up during design, the concentration estimate becomes more accurate. The results indicate that the methods presented provide simple estimates of fugitive emission-based concentrations during the design stages.     

Effects of environmentally relevant concentrations of metallic compounds on the flatfish Scophthalmus maximus: biomarkers of neurotoxicity,oxidative stress and metabolism

Flatfish species, such as the turbot (Scophthalmus maximus), are common targets for toxic effects, since they are exposed through the food chain (ingestion of contaminated preys) and are in direct contact with the waterborne contaminant and sediments. Furthermore, these fish species live in close proximity to interstitial water that frequently dissolves high amounts of contaminants, including metals. Despite this significant set of characteristics, the present knowledge concerning flatfish contamination and toxicity by metals is still scarce. To attain the objective of assessing the effects of metals on a flatfish species, S. maximus specimens were chronically exposed to lead, copper and zinc, at ecologically relevant concentrations, and biochemical (oxidative stress: catalase and glutathione S-transferases activities, and lipid peroxidation; neurotoxicity: cholinesterase activity) parameters were assessed on selected tissues (gills and liver). Copper had no significant effects on all tested parameters; lead was causative of significant increases in liver GSTs activities and also in lipoperoxidation of gill tissue; exposure to zinc caused a significant increase in catalase activity of gill tissue. None of the tested metals elicited noteworthy effects in terms of neurotoxicity. The obtained results showed that only the metal lead is of some environmental importance, since it was able to cause deleterious modifications of oxidative nature at relevant concentrations.     

Biliverdin-based egg coloration is enhanced by carotenoid supplementation

Avian eggshell color is remarkably variable among and within species and its possible function has long been controversial. Female birds use biliverdin pigment to color their eggs blue and green. Although evidence is accumulating that blue-green eggshell coloration is costly to produce, the exact mechanisms underlying its expression are little studied. Biliverdin pigment is involved in important maintenance functions such as immune and antioxidant defenses and shows similar properties to carotenoid pigments. Carotenoids play a role as immunoenhancers and have the potential to ameliorate the impact of oxidative processes, although their antioxidant function could be minor for some bird species. Important life-history components can be limited by carotenoid availability, including sexual displays and fecundity. Here we explored if biliverdin-based eggshell pigmentation was affected by carotenoid availability in a seabird, by performing a carotenoid supplementation experiment in female blue-footed boobies (Sula nebouxii) after laying their first egg. In this species, blue eggshell color is associated with incubation patterns, and carotenoid availability affects the crucial trade-off between female foot ornamentation and fecundity. We found that under natural conditions, there was a decline in eggshell color with laying order, suggesting pigment limitation for females. However, carotenoid-supplemented females had enhanced second egg coloration compared to controls, and the color increase was independent of their previous pigment allocation to the first egg. Our results suggest that biliverdin-based eggshell coloration is costly to produce and can be alleviated by current carotenoid availability.     

Hydrogeochemical considerations about the origin of groundwater salinization in some coastal plains of Elba Island (Tuscany,Italy)

Several coastal plains of the Elba Island (Marina di Campo, Portoferraio, Schiopparello, Mola, Porto Azzurro and Barbarossa plains) in Tuscany (Italy) were studied to determine the causes of decline in groundwater quality, using major ion chemistry to establish the causes of groundwater salinization. The study demonstrates that salinization of coastal plain alluvial aquifers is not simply linked to seawater intrusion but is also intimately related to inflows from adjacent aquifers. Ionic ratios, correlation graphs and distribution value maps were employed as the means to understand the hydrochemistry of the study areas. The Mg/Cl ratio in particular can be considered a good tracer to distinguish the main salinization processes that control groundwater chemistry. Seawater intrusion only partly determines the chemistry of some groundwaters, which generally belong to a chloride facies where the salinity is derived principally from freshwater–seawater mixing and the participation of cation exchange. Proceeding inland groundwater quality seems to be principally determined by the inflow of Mg, Ca-HCO₃ or Ca, Na-HCO₃ waters formed from the weathering of silicate minerals in adjoining aquifers. Hydrolysis of these minerals is of prime importance in controlling groundwater chemistry in adjacent alluvial plains. The lateral recharge flows introduce water with a different chemical composition and this variable of freshwater recharge changes the hydrochemistry as a result of mixing between two or more waters types. This situation is further complicated when seawater and base exchange reactions participate, due to seawater intrusion.     

Assessment of a large watershed in Brazil using Emergy Evaluation and Geographical Information System

Humanity's future depends on the preservation of natural ecosystems that supply resources and absorb pollutants. Rural and urban productions are currently based on chemical products made from petroleum, which are responsible for high negative impacts on the Biosphere. In order to prevent those impacts, efficient public policies seeking for sustainable development are necessary. Aiming to assess the load on the environment (considering the gratuitous contributions of natural systems—a donor's perspective) due to human-dominated process, a scientific tool called Emergy Evaluation has been applied in different production systems, including crops and farms. However, there is still a lack of emergy studies in the context of watersheds, probably due to the difficulty of collecting raw data. The present work aims to carry out an assessment of Mogi-Guaçu and Pardo watershed, through the combined use of Emergy Evaluation and Geographical Information System. The agricultural and natural land uses were considered, while urban areas were excluded. Emergy flows (expressed in seJ ha⁻¹ yr⁻¹) obtained for all agricultural and natural land uses were expanded for the whole watershed and the emergy indices were calculated. The results show that the watershed has: low renewability (%R = 32%); low capture of natural resources through high external economic investment (EYR = 1.86); low dependence on natural resources (EIR = 1.16); and moderate load on the environment (ELR = 2.08). Considering a scenario where sugar-cane crops, orchards and pasture areas are converted from conventional to organic management, watershed's emergy performance improved, reaching a new renewability of 38%, but it is still not enough to be considered sustainable.