Geologic occurrences of erionite in the United States: an emerging national public health concern for respiratory disease

Erionite, a mineral series within the zeolite group, is classified as a Group 1 known respiratory carcinogen. This designation resulted from extremely high incidences of mesothelioma discovered in three small villages from the Cappadocia region of Turkey, where the disease was linked to environmental exposures to fibrous forms of erionite. Natural deposits of erionite, including fibrous forms, have been identified in the past in the western United States. Until recently, these occurrences have generally been overlooked as a potential hazard. In the last several years, concerns have emerged regarding the potential for environmental and occupational exposures to erionite in the United States, such as erionite-bearing gravels in western North Dakota mined and used to surface unpaved roads. As a result, there has been much interest in identifying locations and geologic environments across the United States where erionite occurs naturally. A 1996 U.S. Geological Survey report describing erionite occurrences in the United States has been widely cited as a compilation of all US erionite deposits; however, this compilation only focused on one of several geologic environments in which erionite can form. Also, new occurrences of erionite have been identified in recent years. Using a detailed literature survey, this paper updates and expands the erionite occurrences database, provided in a supplemental file (US_erionite.xls). Epidemiology, public health, and natural hazard studies can incorporate this information on known erionite occurrences and their characteristics. By recognizing that only specific geologic settings and formations are hosts to erionite, this knowledge can be used in developing management plans designed to protect the public.     

Learned recognition of novel predator odour by convict cichlid embryos

Predation exerts tremendous selection pressure on all organisms. In this study, we exposed embryos of convict cichlids (Amatitlania siquia) twice daily to one of the following: (1) chemical alarm cues of damaged conspecifics + odour of a novel predator (Polypterus endlicheri), (2) chemical alarm cues of damaged conspecifics + water or (3) blank water. No chemical cues were presented after the eggs hatched. When the larvae were 9 days old (mean total length?=?5.7 mm), they were exposed to either predator odour or water. Those larvae that had been conditioned as embryos on alarm cues + predator odour showed a significant reduction in activity (i.e. anti-predator behavioural response) to predator odour relative to the other treatments. This is the first demonstration of acquired predator recognition by fish embryos.     

Biological impacts of ocean acidification: a postgraduate perspective on research priorities

Research into the effects of ocean acidification (OA) on marine organisms has greatly increased during the past decade, as realization of the potential dramatic impacts has grown. Studies have revealed the multifarious responses of organisms to OA conditions, indicating a high level of intra- and interspecific variation in species’ ability to accommodate these alterations. If we are to provide policy makers with sound, scientific input regarding the expected consequences of OA, we need a broader understanding of these predicted changes. As a group of 20 multi-disciplinary postgraduate students from around the globe, with a study focus on OA, we are a strong representation of ‘next generation’ scientists in this field. In this unique cumulative paper, we review knowledge gaps in terms of assessing the biological impacts of OA, outlining directions for future research.     

Structural and functional vulnerability to elevated pCO2 in marine benthic communities

The effect of elevated pCO₂/low pH on marine invertebrate benthic biodiversity, community structure and selected functional responses which underpin ecosystem services (such as community production and calcification) was tested in a medium-term (30 days) mesocosm experiment in June 2010. Standardised intertidal macrobenthic communities, collected (50.3567°N, 4.1277°W) using artificial substrate units (ASUs), were exposed to one of seven pH treatments (8.05, 7.8. 7.6, 7.4, 7.2, 6.8 and 6.0). Community net calcification/dissolution rates, as well as changes in biomass, community structure and diversity, were measured at the end of the experimental period. Communities showed significant changes in structure and reduced diversity in response to reduced pH: shifting from a community dominated by calcareous organisms to one dominated by non-calcareous organisms around either pH 7.2 (number of individuals and species) or pH 7.8 (biomass). These results were supported by a reduced total weight of CaCO₃ structures in all major taxa at lowered pH and a switch from net calcification to net dissolution around pH 7.4 (Ω_calc = 0.78, Ω_ara = 0.5). Overall community soft tissue biomass did not change with pH and high mortality was observed only at pH 6.0, although molluscs and arthropods showed significant decreases in soft tissue. This study supports and refines previous findings on how elevated pCO₂ can induce changes in marine biodiversity, underlined by differential vulnerability of different phyla. In addition, it shows significant elevated pCO₂-/low pH-dependent changes in fundamental community functional responses underpinning changes in ecosystem services.     

The physiological and molecular responses of larvae from the reef-building coral Pocillopora damicornis exposed to near-future increases in temperature and pCO2

Given the threats of greenhouse gas emissions and a changing climate to marine ecosystems, there is an urgent need to better understand the response of not only adult corals, which are particularly sensitive to environmental changes, but also their larvae, whose mechanisms of acclimation to both temperature increases and ocean acidification are not well understood. Brooded larvae from the reef coral Pocillopora damicornis collected from Nanwan Bay, Southern Taiwan, were exposed to ambient or elevated temperature (25 or 29 °C) and pCO₂ (415 or 635 μatm) in a factorial experiment for 9 days, and a variety of physiological and molecular parameters were measured. Respiration and rubisco protein expression decreased in larvae exposed to elevated temperature, while those incubated at high pCO₂ were larger in size. Collectively, these findings highlight the complex metabolic and molecular responses of this life history stage and the need to integrate our understanding across multiple levels of biological organization. Our results also suggest that for this pocilloporid larval life stage, the impacts of elevated temperature are likely a greater threat under near-future predictions for climate change than ocean acidification.     

Spatial variogram estimation from temporally aggregated seabird count data

Seabird abundance is an important indicator for assessing impact of human activities on the marine environment. However, data collection at sea is time consuming and surveys are carried out over several consecutive days for efficiency reasons. This study investigates the validity of aggregating those data over time to estimate a spatial variogram that is representative for spatial correlation in species abundance. For this purpose we simulate four-day surveys of seabird count data that contain spatial and temporal correlation arising from temporal changes in the spatial pattern of environmental conditions. Estimates of the aggregated spatial variogram are compared to a variogram that would arise when data were collected over a single day. The study reveals that, under changing environmental conditions over surveys days, aggregating data over a four-day survey increases both the non-spatial variation in the data and the scale of spatial correlation in seabird data. Next, the effect of using an aggregated variogram on the statistical power to test the significance of an impact is investigated. The impact concerns a case of establishing an offshore wind farm resulting in seabird displacement. The study shows that both overestimation and underestimation of statistical power occurs, with power estimates differing up to a factor of two. We conclude that the spatial variation in seabird abundance can be misrepresented by using temporally aggregated data. In impact studies, such misrepresentation can lead to erroneous assessments of the ability to detect impact.     

How wave exposure, group size and habitat complexity influence foraging and population densities in fishes of the genus Halichoeres (Perciformes: Labridae) on tropical rocky shores

Wave exposure and habitat complexity have been used to explain variations in the distribution patterns and behavior of many reef fishes. This study analyzed the influence of both factors on density and foraging activity, and the influence of group size on foraging in three species of the genus Halichoeres (Labridae) on tropical rocky shores. It was shown that initial phases (IP) and terminal phases (TP) Halichoeres, were influenced by wave exposure, although foraging in Halichoeres brasiliensis TP was not influenced by wave exposure. The IP in all three species were positively associated with rugosity and algal cover while the TP was positively associated with depth. Habitat complexity also influences foraging in these species. Group size influenced foraging activity, except in H. brasiliensis TP. We also found variations in microhabitat patches used for foraging between species and differences in the stomach contents between species and phases, showing that functional roles change in response to ontogenetic shifts.     

Novel molecular fingerprinting of marine avian diet provides a tool for gaining insights into feeding ecology

C₂₅ highly branched isoprenoids (HBIs) are produced by a relatively small number of diatom species, yet are common constituents of almost all marine environments. Previously, detection of HBIs in a few aquatic Arctic animals has indicated the potential use of these lipids for providing novel ecological information. In the current study, analysis of lipid extracts of livers from Leach’s storm petrel (Oceanodroma leucorhoa) and Brunnich’s guillemot (Uria lomvia) facilitated identification and quantification of HBI isomers. HBIs were found in the tissues of all specimens with clear differences in the abundances and distributions of individual HBI isomers both between Atlantic as well as Arctic birds. These differences are consistent with contrasting oceanographic regimes and suggests that regional differences in HBIs are reflected in the tissues of consumers. Tissue-specific assessment of HBI distributions has also revealed the presence of these lipids in muscle for the first time. This study represents the first report of HBI lipids in birds and provides evidence that these lipids are transferred across trophic levels and extends their potential use as chemical tracers beyond the ecology of aquatic organisms.     

Site-specific and integrated adaptation to climate change in the coastal mangrove zone of Soc Trang Province, Viet Nam

The dynamic coastline of Soc Trang Province in the Mekong Delta of Viet Nam is in most parts protected from erosion, storms and flooding by a narrow belt of mangroves. However, the unsustainable use of natural resources and development in the coastal zone is threatening the protection function of this forest belt. This situation is exacerbated by the impacts of climate change, particularly by the increased intensity and frequency of storms, floods and by rising sea levels. Based on analysis of past experience of mangrove planting and historical changes in mangrove cover, an integrated and site-specific approach to adaptation to climate change has been put in place, which comprises mangrove planting and rehabilitation with emphasis on resilience to climate change, and participatory involvement of local communities in effective mangrove management and protection through co-management. To address uncertainties associated with the impacts of climate change, testing of new mangrove planting techniques has started. This includes mimicking successful natural regeneration for small-scale planting in sites with high wave energy and transformation of existing even-aged plantations into more diverse forests—both in terms of structure and species composition. The pre-requisite for mangrove rehabilitation in erosion sites has successfully been put in place: breakwaters made from bamboo have reduced erosion and stimulated sedimentation. The design and construction of the wave-breaking structures, which was based on a numerical model which simulates hydrodynamics and shoreline development, ensures that downdrift erosion can be avoided as far as possible. A comprehensive monitoring program has been established and initial results provide evidence for the effectiveness of the bamboo breakwaters. Early experience shows that co-management is an effective way of maintaining and enhancing the protection function of the mangrove forest belt and at the same time providing livelihood for local communities. Payment for ecosystem services contributes to sustainability of co-management as well as livelihood improvement.     

Evolution of spit morphology: a case study using a remote sensing and statistical based approach

The dynamics and factors responsible for morphological changes of spits viz., Uliyargoli-Padukere, Oddu Bengre and Kodi Bengre, southern Karnataka, India, are investigated using multi-dated satellite images and topographic maps during the last 95-years (1910–2005). Variations and overall rate of changes in length, area and coefficient of determination (R²) of each spit are calculated separately for two periods (1910 and 1967 as base years) to find out whether there is any significant trend in the case of change in length and area in all the three spits that are under study. Linear trend lines are fitted using a least squares method and the statistical significance is considered at 80 % level of confidence. The results recorded significant changes in spit morphology, especially in length and area if 1910 and 1967 are considered separately as base years, are may be due to non-availability of data set between 1910 and 1967 period. The study reveals that coastal processes, such as SW-monsoon influenced strong currents and longshore drifts are the main process for formation and growth of spits, whereas rivers influence/drift also plays significant role. The statistical uncertainty estimation in spits morphology is prevalent wherever the coast is affected by human interventions. The study demonstrates that combined use of satellite imagery and statistical techniques can be effectively used to understand the evolution of spits morphology.