Two mechanisms of aquatic and terrestrial habitat change along an Alaskan Arctic coastline

Arctic habitats at the interface between land and sea are particularly vulnerable to climate change. The northern Teshekpuk Lake Special Area (N-TLSA), a coastal plain ecosystem along the Beaufort Sea in northern Alaska, provides habitat for migratory waterbirds, caribou, and potentially, denning polar bears. The 60-km coastline of N-TLSA is experiencing increasing rates of coastline erosion and storm surge flooding far inland resulting in lake drainage and conversion of freshwater lakes to estuaries. These physical mechanisms are affecting upland tundra as well. To better understand how these processes are affecting habitat, we analyzed long-term observational records coupled with recent short-term monitoring. Nearly the entire coastline has accelerating rates of erosion ranging from 6 m/year from 1955 to 1979 and most recently peaking at 17 m/year from 2007 to 2009, yet an intensive monitoring site along a higher bluff (3–6 masl) suggested high interannual variability. The frequency and magnitude of storm events appears to be increasing along this coastline and these patterns correspond to a greater number of lake tapping and flooding events since 2000. For the entire N-TLSA, we estimate that 6% of the landscape consists of salt-burned tundra, while 41% is prone to storm surge flooding. This offset may indicate the relative frequency of low-magnitude flood events along the coastal fringe. Monitoring of coastline lakes confirms that moderate westerly storms create extensive flooding, while easterly storms have negligible effects on lakes and low-lying tundra. This study of two interacting physical mechanisms, coastal erosion and storm surge flooding, provides an important example of the complexities and data needs for predicting habitat change and biological responses along Arctic land–ocean interfaces.     

Rapid risk assessment of wetland degradation and loss in low-lying coastal zone of Shanghai,China

Coastal wetlands are facing an increasingly high risk of degradation and loss due to a wide variety of human activities and natural processes. Human encroachment, including land reclamation, drainage, and introduction of invasive species, has direct negative effects on wetlands, mainly through changes in hydrology and vegetation. Additionally, accelerated sea level rise (SLR) can result in flooding of wetlands in low-lying coastal zones. In this study, we present a rapid risk assessment method for coastal wetland loss and degradation. The main stress factors, i.e., urban sprawl, agriculture, coastal erosion, and SLR, have been examined and quantified through remote sensing and geographic information system spatial analysis. A weighted factor-based linear model has been used to evaluate the spatial risk levels of wetland loss. The proposed methodology is applied to the low-lying coastal wetlands of Hangzhou Bay in Shanghai, China. The results show that the regions closer to the sea have relatively higher risk levels on the landward side of the coastline, but relatively low risk levels on the seaward side of the coastline. This work emphasizes the need to sustainably use and protect wetlands in order to reduce disaster risks and contribute to the improvement of human well-being.     

Genetic population structure of Indian oil sardine, <Emphasis Type="Italic">Sardinella longiceps</Emphasis> assessed using microsatellite markers

Indian oil sardines, commercially and ecologically important pelagic fishes in Indian waters have not been the focus of major genetic studies as compared to their counter parts in Atlantic and Pacific oceans in spite of several reports suggesting stock complexity and intraspecific diversity. Hence, we investigated the genetic stock structure of Indian oil sardine, Sardinella longiceps using microsatellite markers by collecting a total of 768 individuals from eight locations along the Indian coast and one from Gulf of Oman over a 2 year period (2013–2015). Six polymorphic microsatellite markers revealed significant genetic differentiation between populations with the highest F_ST value (0.055) between Oman and Indian coastline. Within the Indian coastline another major subdivision between Mumbai & Mangalore vs. other regions was detected (F_ST value 0.047) which was also confirmed in Barrier analysis with the presence of two strong barriers between these eco-regions. There exist pronounced differences in oceanographic and environmental features between Gulf of Oman, Western Indian Ocean and Eastern Indian Ocean (Bay of Bengal) which may act as barriers for effective dispersal and gene flow resulting in genetic differentiation. Even though, the samples collected from Calicut, Kollam, Trivandrum, Chennai and Vizag showed the presence of admixed genotypes, the possible presence of distinct populations in some regions was evident in Bayesian analysis which needs to be confirmed further using more widespread sampling design and powerful markers. The present study provided insights into the biocomplexity and intra-specific diversity of Indian oil sardine populations, which needs to be preserved for maintaining resilience of these important fishes to climate change and habitat alterations in the Indian Ocean.     

Shifting Urban Margins: Accessing Unequal Spaces of Ageing and Care in Zanzibar and Muscat

ABSTRACT

Older people constitute a growing proportion of the urban population and are encountered in all kinds of spaces and neighbourhoods across cities. This article argues that urban seniority and elderly care are a fruitful, new lens to study how inhabitants on the social margins create urban space and social cohesion. This article draws on ethnographic research in the cities of Zanzibar, Tanzania, and Muscat, the capital of Oman. Many older inhabitants of cities experience frailty, serious health problems, or even disabilities and are no longer able to work or make a living, which pushes them towards the social margins. The ethnographic examples and reflections in this article illustrate, first, how cities can be investigated from the perspective of social and spatial marginality. Second, they show how urban dwellers’ social positions can shift between the margins and centres of an urban society depending on their health and access to unequal spaces of ageing and care. And third, the paper analyses how some elders respond to marginality by taking up transnational and cosmopolitan agency.     

Molecular epidemiological approaches to the study of the genotoxic effects of urban air pollution.

Direct epidemiological observations suggest that exposure to high levels of urban air pollution may result in increased risk of lung cancer, sufficient to account for a few (approximately 1-3) percent of total lung cancer incidence. Extrapolation from occupational exposure and risk data suggests that among potential carcinogens present in polluted urban air, polycyclic aromatic hydrocarbons (PAHs) may make a major contribution to air pollution-associated lung cancer risks. The use of biomarkers of genotoxocity in large-scale population studies may help to reduce the uncertainty involved in the assessment of such risks, especially those associated with relatively low pollution levels such as nowadays found in many Western cities. Increases in biomarkers of exposure to urban air PAHs as well as biomarkers of early effects have been detected in situations of relatively high levels of air pollution (e. g., ambient PAH concentrations of the order of a few tens of micrograms per cubic meter). Evidence has also been found about the modulation genetic damage accumulation in different individuals by polymorphisms in genes involved in the activation or detoxification of PAHs, especially of polymorphisms GSTM1 and CYP1A1 genes. However, the inconsistencies in the currently reported effects of genetic polymorphisms suggest that additional factors may also be important in the modulation of individual susceptibility to the accumulation of PAH-derived genetic damage. Biomarkers studies in populations exposed to relatively low ambient PAH concentrations (below 20 microg/m(3)) have not demonstrated clear dose-related effects (e.g., on DNA adduct levels), possibly because of the existence of multiple sources and routes of human exposure to PAHs in addition to inhalation of urban air (including, for example, home heating, environmental tobacco smoke and diet), and the consequent difficulty of adequately and specifically assessing atmospheric air-related exposure. This makes it imperative that molecular epidemiology studies be designed in such a way as to allow adequate assessment of exposure to urban air PAHs at the individual level and over short-, medium- and long-term time periods which correspond to the expression times of different biomarkers.     

Risk management in biological evolution

I present a framework to study the evolution of traits that allow an organism to survive life-threatening but rare risks. Specifically, I am concerned with risks so rare that any one individual in a population may not experience the risk-causing event in its lifetime. A theory of rare risk management is virtually absent in evolutionary biology, although it is well developed in economics. This is surprising because of the great influence economics had on evolutionary biology, and because biology is full of examples for evolved risk management traits. They include the ability of bacteria to sporulate, of pathogens to survive antibiotic treatment, of temperate bacteriophages to enter a lytic life cycle, as well as traits that allow higher organisms to survive rare environmental disasters, such as sporadic wildfires and irregular flooding. I make predictions about the sustenance of risk management traits under two scenarios, one where the catastrophic events cause individual deaths, and another one where catastrophic events cause population extinction. A well-developed theory of risk management will not only predict the distribution of risk management traits, but may also serve other purposes, such as to reconstruct the spectrum of environments that an organism encountered in its evolutionary history from the record stored in its genome's memory.     

Culture as a stressor: A revised model of biocultural interaction

Contemporary urban societies display in high relief the action of social stratification on human biology. Recent studies of biological responses to urban environments and of socioeconomically disadvantaged people indicate that culture allocates risks disproportionately to some individuals and groups within society through its constituent values and related patterns of behavior. Although risk allocation is present in all societies, it is very clear in urban environments within stratified societies where high exposure to harmful materials is many times more likely for some segments of society. In urban environments, culture may be seen as adding stressors to the environment by concentrating naturally occurring materials to levels that are toxic to humans and through the creation of new toxic materials. In stratified societies the risk of exposure to these new stressors is focused on the socioeconomically disadvantaged. This exposure has consequences that increase the likelihood of more exposure and more socioeconomic disadvantage, thereby increasing social stratification. This suggests that models of biocultural interaction include a feedback relationship in which biological factors influence the sociocultural system in addition to the usual action of the sociocultural system on biological features and responses. This model strongly reinforces the view that stressors can originate from cultural arrangements. Am J Phys Anthropol 102:67–77, 1997 © 1997 Wiley-Liss, Inc.     

Early dynamics in plant community trait responses to a novel,more extreme hydrological gradient

Aims For temperate regions such as Northern Europe, predicted climate change patterns include an increase in winter precipitation causing increased risk of flooding, whereas periods of droughts will become more frequent in summer. The aim of this study is to explore variations in plant functional trait distributions along a hydrological gradient spanning from recurrent drought events to recurrent flooding—mimicking future precipitation patterns.     

PCR analysis of the distribution of unicellular cyanobacterial diazotrophs in the Arabian Sea

An oligonucleotide primer, NITRO821R, targeting the 16S rRNA gene of unicellular cyanobacterial N2 fixers was developed based on newly derived sequences from Crocosphaera sp. strain WH 8501 and Cyanothece sp. strains WH 8902 and WH 8904 as well as several previously described sequences of Cyanothece sp. and sequences of intracellular cyanobacterial symbionts of the marine diatom Climacodium frauenfeldianum. This oligonucleotide is specific for the targeted organisms, which represent a well-defined phylogenetic lineage, and can detect as few as 50 cells in a standard PCR when it is used as a reverse primer together with the cyanobacterium- and plastid-specific forward primer CYA359F (U. Nubel, F. Garcia-Pichel, and G. Muyzer, Appl. Environ. Microbiol. 63:3327-3332, 1997). Use of this primer pair in the PCR allowed analysis of the distribution of marine unicellular cyanobacterial diazotrophs along a transect following the 67 degrees E meridian from Victoria, Seychelles, to Muscat, Oman (0.5 degrees S to 26 degrees N) in the Arabian Sea. These organisms were found to be preferentially located in warm (>29 degrees C) oligotrophic subsurface waters between 0 and 7 degrees N, but they were also found at a station north of Oman at 26 degrees N, 56 degrees 35'E, where similar water column conditions prevailed. Slightly cooler oligotrophic waters (<29 degrees C) did not contain these organisms or the numbers were considerably reduced, suggesting that temperature is a key factor in dictating the abundance of this unicellular cyanobacterial diazotroph lineage in marine environments.     

Pollution,sources, and risks of heavy metals in coastal waters of China

Abstract

Comprehensive information on heavy metals in coastal waters at national scale of China is limited. Therefore, this study investigated the distribution, pollution, and ecological-health risks of heavy metals in coastal waters along 18,000?km coastline of China. Total 13 target heavy metals in coastal waters along coastline of China showed drastic spatial variations with average concentrations ranging from .14 (Cd) to 136.26 (Cu) μg/L. Cu was the dominant heavy metal with the maximal concentration of 1485.92?μg/L. Three methods including heavy metal pollution index (HPI), Nemerow index (NI), and contamination degree (CD) were adopted to explore heavy metal pollution. HPI obtained the worst-case evaluation results to illustrate that heavy pollution occurred at over 50% of sampling sites. Anthropogenic sources were the main sources of heavy metals in the coastal waters. Approximately 28.13% and 9.38% of sampling sites illustrated considerable and very high ecological risks, respectively. Metals including Cu, As, and Hg were the main pollution and risk contributors. Heavy metals in coastal waters posed high cancer risks and unacceptable non-cancer risks to both adults and children. Therefore, effective control of heavy metals is necessary for regional sustainability and well-beings of residents in coastal regions of China.     

Genetic signature of the colonisation dynamics along a coastal expansion front in the damselfly Coenagrion scitulum

1. Many insects are expanding their distribution range polewards as a result of climate change, which has been shown to be associated with founder effects leading to a reduction in genetic diversity and an increase in genetic differentiation. These spatial genetic patterns may arise from colonisation from a broad expansion front or a limited neighbourhood after a stepping stone model of dispersal. The temporal persistence of such founder effects are poorly understood, mainly because studies looking at the fine‐scale initial temporal dynamics of the genetic signature of a range expansion are rare. 2. Using microsatellite markers, we performed a detailed spatiotemporal genetic analysis of the range expanding damselfly Coenagrion scitulum (Rambur) along a coastal axis during the first years after colonisation. 3. A decrease was in (private) allelic richness when going northwards along the coastline, which is consistent with a scenario of cumulative founder events. In spite of the spatiotemporal dynamics in the observation records of the species along the coastline, the spatial genetic data indicated a major contribution from the broad expansion front during the colonisation of the coastline rather than a stepping‐stone colonisation process. 4. The fine‐scale temporal dynamics of the range expansion indicated the absence of persistent founder effects and instead showed considerable temporal instability in genetic indices at the more northern edge populations. This may be explained by genetic immigration and admixture from the broad expansion front in this active disperser.     

Coastal-flood risk management in central Algarve: Vulnerability and flood risk indices (South Portugal)

This paper presents an analysis of the vulnerability (AVI Index) and hazard of flooding by sea level rise (FRI Index) in the central Algarve (South Portugal), between the cities of Portimão and Tavira, which is an area of intense urban impact and fast growing tourism. The vulnerability index was calculated using the following parametric thematic maps: lithology, geomorphology, slopes, elevations, distances, bathymetry, variations of the coastline, wave height and activity, variations of sea level and tidal range. The AVI Index was validated by the results obtained from the analysis of the risk of flooding from the FHI Index applied to several time horizons (X₀-present, X₁-100 years, X₂-500 years, X₃-1000 year, X₄-Storm and X₅-Tsunami). Application of GIS and remote sensing techniques, viz. spatial analysis, interpolation processes and geostatistical analysis, permitted a regional forecasting model of change in the mean sea level and the ensuing consequences to be established. Analysis of the obtained results shows an increase in potential flood zones in populous coastal tourist areas with a high risk of exposure and a significant spatial extent of 8.84 km² only in Faro municipality. The assessment and delineation of other endangered sectors could contribute to designing appropriate long- term management policies for the coastal of Central Algarve.     

城市生态风险评价研究进展

随着城市化发展和城市人居环境的恶化,城市生态风险越来越受到关注,但尚缺乏有关城市生态风险评价的深入系统研究.本文依据城市生态学原理及生态风险评价框架从驱动力、风险源、风险受体与评价终点,以及生态风险综合评价方法等方面对城市生态风险评价研究进行综述.指出城市经济社会活动类型与程度是城市生态风险产生的主要驱动力;城市生态系统不同等级功能实体和城市整体是城市生态风险评价中的风险受体;城市生态风险评价终点包括城市生态系统结构、过程、功能要素,以及城市整体水平的性质和功能变化;耦合了社会经济需求的生态系统模型是城市生态风险评价方法的发展方向.未来城市生态风险评价研究应明确生态风险管理具体目标,确定综合性评价终点,建立多指标评价体系和综合评价方法.     

Flood history and river flow variability recorded in tree rings on the Dhur River,Bhutan

During the 2018 WorldDendro fieldweek in Bhutan, we examined the flood history of the Dhur River. Most villages are located along streams, so knowing the flood history of the area will enable managers to prepare for future events. We collected scarred partial cross sections from 29 trees along a two km stretch of the Dhur River, and two cores per tree from 29 other trees from six species (Populus ciliata, Picea spinulosa, Tsuga dumosa, Quercus semecarpifolia, Pinus wallichiana, and Rhododendron arboreum). We identified large flood events in 2009, 1989, and 1967 from at least two trees with flood scars or traumatic rings. Our flood-scar chronology extends to 1940 with five cross-sectioned trees, and back to 1904 with core evidence from two trees. The oldest flood scar occurred in 1967. The 2009 flood scar was recorded in most of our streamside samples and is the result of heavy precipitation from Cyclone Aila at the end of May 2009. Two other storms and proceeding flood events occurred in 1989 and 1967 according to additional scars detected in several samples. This work demonstrates the successful use of density fluctuations in Pinus along with scarring in multiple species to reconstruct past flood events and identifies the effects of Cyclone Aila, as an extreme event for this area, which was unprecedented for the past hundred years.     

Multiple biomarkers of pollution effects in caged mussels on the Greek coastline

A suite of biomarkers was measured in caged mussels at areas impacted by different anthropogenic activities along the Greek coastline to assess biological effects of environmental pollution. Mussels were caged at coastal sites in the vicinity of major cities, in areas influenced by major industries, agricultural practices and in islands away from known sources of pollution. Biomarkers indicative of neurotoxicity (acetylcholinesterase, AchE), oxidative stress (catalase, CAT), phase II biotransformation of xenobiotics (glutathione S-transferase, GST), metal exposure (metallothioneins, MTs) and protein synthesis (RNA:DNA ratio) were measured to assess effects of various types of pollutants. AchE activity proved to be the most responsive biomarker with decreased values at sites influenced by agricultural, urban and industrial activities. Decreased CAT and GST activities and increased MTs levels were recorded at a number of anthropogenic-impacted sites. RNA:DNA ratio showed a biphasic response as both high and low values were found at impacted sites. Principal component analysis clearly distinguished sites receiving pollution inputs from non-polluted sites. The combination of the selected biomarkers used in caged mussels resulted useful in the assessment of the effects of environmental pollution.     

ABO,Rh(D) and haptoglobin distribution in a sample from the sultanate of Oman

The distribution of phenotypic frequencies of ABO, Rh(D) system and Hp polymorphism in a sample from Muscat, Oman, revealed the following gene frequencies: P=0.164, q=0.110, r=0.726; D=0.738, d=0.262; Hp¹=0.289 and Hp²=0.711. These frequencies are in good agreement with the distribution in the Euroasiatic continent.     

Differential neuroprotective activity of two different grape seed extracts

Glutamate excitotoxicity is one of the major events that takes place during various neurotoxic injuries such as brain ischemia. We prepared grape seed extracts, from two different varieties, containing high amounts of polyphenols but little resveratrol. Their neuroprotective effects were investigated using primary culture of neonatal mouse hippocampal neurons treated with an excitotoxic concentration of glutamate. Koshu, a white, local variety of V. vinifera, alleviated the acute inactivation of Erk1/2 and dendrite retraction in cultured hippocampal neurons exposed to a toxic concentration of glutamate (1.0 ng/ml). By contrast, Muscat Bailey A, a red, hybrid variety (Muscat Humburg × Bailey), failed to show any neuroprotective effect. Unlike brain-derived neurotrophic factor and other neuroprotective cytokines, Koshu extract did not induce Akt phosphorylation. Koshu extract also augmented neuron survival rate 24 hours after glutamate toxicity. The comparison of polyphenols between the two samples by liquid chromatography/time-of-flight mass spectrometry demonstrated that Koshu had higher amounts of low molecular weight polyphenols along with several Koshu-specific procyanidin oligomers. These data suggest the presence of high affinity molecular targets for polyphenols in hippocampal neurons, which induce neuroprotective effects in a manner different from BDNF, and the importance of low molecular weight polyphenols and/or procyanidin oligomers for neuroprotection.     

Teratogen update: lead and pregnancy

This review focuses on the impacts of lead exposure on reproductive health and outcomes. High levels of paternal lead exposure (>40 microg/dl or >25 microg/dl for a period of years) appear to reduce fertility and to increase the risks of spontaneous abortion and reduced fetal growth (preterm delivery, low birth weight). Maternal blood lead levels of approximately 10 microg/dl have been linked to increased risks of pregnancy hypertension, spontaneous abortion, and reduced offspring neurobehavioral development. Somewhat higher maternal lead levels have been linked to reduced fetal growth. Some studies suggest a link between increased parental lead exposure and congenital malformations, although considerable uncertainty remains regarding the specific malformations and the dose-response relationships. Common methodological weaknesses of studies include potential exposure misclassifications due to the frequent unavailability of exposure biomarker measurements at biologically appropriate times and uncertainty regarding the best exposure biomarker(s) for the various outcomes. A special concern with regard to the pregnant woman is the possibility that a fetus might be exposed to lead mobilized from bone stores as a result of pregnancy-related metabolic changes, making fetal lead exposure the result of exposure to exogenous lead during pregnancy and exposure to endogenous lead accumulated by the woman prior to pregnancy. By reducing bone resorption, increased calcium intake during the second half of pregnancy might reduce the mobilization of lead from bone compartments, even at low blood lead levels. Subgroups of women who incurred substantial exposures to lead prior to pregnancy should be considered to be at increased risk.     

Myelogenous leukemia and electric blanket use

In a case-control study of adult acute and chronic myelogenous leukemia in Los Angeles County, we tested the hypothesis that excess exposure to electromagnetic fields from electric blankets was associated with risk of leukemia. We did this by studying 116 cases of acute myelogenous leukemia (AML) and 108 cases of chronic myelogenous leukemia (CML) along with matched neighborhood controls. The cases and controls were queried as to electric blanket use and the risks computed. For AML the risk was 0.9 (95% CI 0.5-1.6) and for CML the risk was 0.8 (95% CI 0.4-1.6). Cases did not differ from controls by duration of use, year of first regular use, year since last use, or socioeconomic status. Our best estimates of exposure indicate that electric blanket use increases overall exposure to electric fields by less than 50% and magnetic fields by less than 100%. We conclude that there is no major leukemogenic risk associated with electric blanket use in Los Angeles County.     

Urbanization and the temporal patterns of social networks and group foraging behaviors

Urbanization causes dramatic and rapid changes to natural environments, which can lead the animals inhabiting these habitats to adjust their behavioral responses. For social animals, urbanized environments may alter group social dynamics through modification of the external environment (e.g., resource distribution). This might lead to changes in how individuals associate or engage in group behaviors, which could alter the stability and characteristics of social groups. However, the potential impacts of urban habitat use, and of habitat characteristics in general, on the nature and stability of social associations remain poorly understood. Here, we quantify social networks and dynamics of group foraging behaviors of black‐capped chickadees (N = 82, Poecile atricapillus), at four urban and four rural sites weekly throughout the nonbreeding season using feeders with radio frequency identification of individual birds. Because anthropogenic food sources in urban habitats (e.g., bird feeders) provide abundant and reliable resources, we predicted that social foraging associations may be of less value in urban groups, and thus would be less consistent than in rural groups. Additionally, decreased variability of food resources in urban habitats could lead to more predictable foraging patterns (group size, foraging duration, and the distribution of foraging events) in contrast to rural habitats. Networks were found to be highly consistent through time in both urban and rural habitats. No significant difference was found in the temporal clumping of foraging events between habitats. However, as predicted, the repeatability of the clumping of foraging events in time was significantly higher in urban than rural habitats. Our results suggest that individuals living in urban areas have more consistent foraging behaviors throughout the nonbreeding season, whereas rural individuals adjust their tactics due to less predictable foraging conditions. This first examination of habitat‐related differences in the characteristics and consistency of social networks along an urbanization gradient suggests that anthropic habitat use results in subtle modifications in social foraging patterns. Future studies should examine potential implications of these differences for variation in predation risk, energy intake, and information flow.