El Ni?o Southern Oscillation and Leptospirosis Outbreaks in New Caledonia

Leptospirosis is an important cause of seasonal outbreaks in New Caledonia and the tropics. Using time series derived from high-quality laboratory-based surveillance from 2000–2012, we evaluated whether climatic factors, including El Niño Southern Oscillation (ENSO) and meteorological conditions allow for the prediction of leptospirosis outbreaks in New Caledonia. We found that La Niña periods are associated with high rainfall, and both of these factors were in turn, temporally associated with outbreaks of leptospirosis. The sea surface temperature in El Niño Box 4 allowed forecasting of leptospirosis outbreaks four months into the future, a time lag allowing public health authorities to increase preparedness. To our knowledge, our observations in New Caledonia are the first demonstration that ENSO has a strong association with leptospirosis. This association should be tested in other regions in the South Pacific, Asia or Latin America where ENSO may drive climate variability and the risk for leptospirosis outbreaks.     

El Niño,Climate, and Cholera Associations in Piura,Peru, 1991–2001: A Wavelet Analysis

In Peru, it was hypothesized that epidemic cholera in 1991 was linked to El Niño, the warm phase of El Niño–Southern Oscillation. While previous studies demonstrated an association in 1997–1998, using cross-sectional data, they did not assess the consistency of this relationship across the decade. Thus, how strong or variable an El Niño–cholera relationship was in Peru or whether El Niño triggered epidemic cholera early in the decade remains unknown. In this study, wavelet and mediation analyses were used to characterize temporal patterns among El Niño, local climate variables (rainfall, river discharge, and air temperature), and cholera incidence in Piura, Peru from 1991 to 2001 and to estimate the mediating effects of local climate on El Niño–cholera relationships. The study hypothesis is that El Niño-related connections with cholera in Piura were transient and interconnected via local climate pathways. Overall, our findings provide evidence that a strong El Niño–cholera link, mediated by local hydrology, existed in the latter part of the 1990s but found no evidence of an El Niño association in the earlier part of the decade, suggesting that El Niño may not have precipitated cholera emergence in Piura. Further examinations of cholera epicenters in Peru are recommended to support these results in Piura. For public health planning, the results may improve existing efforts that utilize El Niño monitoring for preparedness during future climate-related extremes in the region.     

El Ni?o Southern Oscillation (ENSO) Enhances CO2 Exchange Rates in Freshwater Marsh Ecosystems in the Florida Everglades

This research examines the relationships between El Niño Southern Oscillation (ENSO), water level, precipitation patterns and carbon dioxide (CO₂) exchange rates in the freshwater wetland ecosystems of the Florida Everglades. Data was obtained over a 5-year study period (2009–2013) from two freshwater marsh sites located in Everglades National Park that differ in hydrology. At the short-hydroperiod site (Taylor Slough; TS) and the long-hydroperiod site (Shark River Slough; SRS) fluctuations in precipitation patterns occurred with changes in ENSO phase, suggesting that extreme ENSO phases alter Everglades hydrology which is known to have a substantial influence on ecosystem carbon dynamics. Variations in both ENSO phase and annual net CO₂ exchange rates co-occurred with changes in wet and dry season length and intensity. Combined with site-specific seasonality in CO₂ exchanges rates, El Niño and La Niña phases magnified season intensity and CO₂ exchange rates at both sites. At TS, net CO₂ uptake rates were higher in the dry season, whereas SRS had greater rates of carbon sequestration during the wet season. As La Niña phases were concurrent with drought years and extended dry seasons, TS became a greater sink for CO₂ on an annual basis (−11 to −110 g CO₂ m⁻² yr⁻¹) compared to El Niño and neutral years (−5 to −43.5 g CO₂ m⁻² yr⁻¹). SRS was a small source for CO₂ annually (1.81 to 80 g CO₂ m⁻² yr⁻¹) except in one exceptionally wet year that was associated with an El Niño phase (−16 g CO₂ m⁻² yr⁻¹). Considering that future climate predictions suggest a higher frequency and intensity in El Niño and La Niña phases, these results indicate that changes in extreme ENSO phases will significantly alter CO₂ dynamics in the Florida Everglades.     

The Seasonal Aggregation of Whale Sharks at Ningaloo Reef, Western Australia: Currents, Migrations and the El Niño/ Southern Oscillation

Whale sharks, Rhincodon typus, seasonally aggregate in coastal waters off Ningaloo Reef, Western Australia. We review the oceanographic setting of the region and present evidence that such aggregations form as a result of migratory behavior associated with climatic and oceanographic processes. We utilise records of whale shark abundance collected at Ningaloo Reef from dedicated searches by boat and aircraft and from log sheets recorded by the tourism industry. Measures of whale shark abundance derived from log sheet data sets were moderately correlated with the Southern Oscillation Index and weakly correlated with coastal sea level, an index of the strength of the Leeuwin Current, and sea surface temperature over the period 1993 to 1998. Abundances of whale sharks derived from boat searches from 1983 to 1992 were also correlated with fluctuations in the Southern Oscillation Index, except during a three year period from 1988 to 1990. We conclude that, at least in some years, there appears to be a link between the abundance of aggregating whale sharks and the physical and biological oceanography of the region, with greater whale shark numbers in La Niña years. The lack of correlation in other years may be due to a combination of uneven quality of data and/or aggregations occurring in response to a complex interaction between the physical and biological oceanography of the region.     

Review article. Studying climate effects on ecology through the use of climate indices: the North Atlantic Oscillation, El Niño Southern Oscillation and beyond

Whereas the El Niño Southern Oscillation (ENSO) affects weather and climate variability worldwide, the North Atlantic Oscillation (NAO) represents the dominant climate pattern in the North Atlantic region. Both climate systems have been demonstrated to considerably influence ecological processes. Several other large-scale climate patterns also exist. Although less well known outside the field of climatology, these patterns are also likely to be of ecological interest. We provide an overview of these climate patterns within the context of the ecological effects of climate variability. The application of climate indices by definition reduces complex space and time variability into simple measures, ''packages of weather''. The disadvantages of using global climate indices are all related to the fact that another level of problems are added to the ecology-climate interface, namely the link between global climate indices and local climate. We identify issues related to: (i) spatial variation; (ii) seasonality; (iii) non-stationarity; (iv) nonlinearity; and (v) lack of correlation in the relationship between global and local climate. The main advantages of using global climate indices are: (i) biological effects may be related more strongly to global indices than to any single local climate variable; (ii) it helps to avoid problems of model selection; (iii) it opens the possibility for ecologists to make predictions; and (iv) they are typically readily available on Internet.     

Spatial–temporal distribution of rainfall erosivity,erosivity density and correlation with El Niño–Southern Oscillation in the Huaihe River Basin,China

Rainfall erosivity (RE) is the ability of rainfall to cause soil or regolith erosion. Understanding the spatial distribution and temporal trends of RE is critical for assessing soil erosion risk and improving upon soil conservation planning. The aim of this paper is to study the temporal and spatial changes in RE in the Huaihe River Basin, China. This will be based on daily precipitation data from 67 meteorological stations in the Huaihe River Basin for the period 1971 to 2016. The assessment of the resulting RE values involved inverse distance-weighted (IDW) interpolation, Sen's slope estimation, and the Mann-Kendall nonparametric test. In addition, the possible influence of the El Niño – Southern Oscillation (ENSO) on RE in the Huaihe River Basin will be examined by the use of Cross Wavelet Transform (XWT) and Wavelet Coherence (WTC), where the relationship between RE and the multivariate ENSO index (MEI) are analyzed. The results showed that the spatial distribution of RE is characterized by it increasing from west to east and north to south. In most areas, the annual RE has increased slightly, while this upward trend in the southeastern part of the study area was more significant. The rainfall erosivity of rainstorms (RE-SM) in the Huaihe River Basin played a leading role in the annual RE, and 97% of the stations displayed the order of importance of the different categories of rainfall as rainfall erosivity of rainstorms (RE-SM) > rainfall erosivity of heavy rain (RE-HR) > rainfall erosivity of moderate rain (RE-MR). Over monthly time scales, the RE was the highest in July, while it was lowest in December, with the monthly differences being apparent. The RE in the Huaihe River Basin were relatively large during non-El Niño/La Niña periods and relatively small during El Niño/La Niña periods. Finally, correlations between RE and the MEI in various parts of the basin showed different characteristics over time and space, with both displaying similarities and differences.     

Effect of nutrient availability on understory algae during El Ni?o Southern Oscillation (ENSO) conditions in Central Pacific Baja California

An experimental study of the effect of artificial nutrient supply on understory algae was made during 1997 El Ni?o Southern Oscillation (ENSO) at the Mexican Pacific coast of Baja California. Twelve quadrats of 1 m² were placed on the sea bed. Six quadrats were used as controls, and six were treatments with added artificial nutrients. Nutrients were supplied using polyvinyl chloride (PVC) pipes filled with slow-release inorganic fertilizer. The algae species composition and cover in each quadrat were estimated using the random point quadrat method. The percent of cover was tested using a multifactorial analysis of variance, and significant differences were obtained by post hoc Tukey’s HSD test. The analysis was carried out annually, seasonally, and seasonal and monthly for each species. The seawater temperature was recorded, and compared with historical data. The bottom and surface seawater nitrate concentration were measured. Twenty-five species of macroalgae and one seagrass were identified. The most abundant species was Corallina vancouveriensis (−N = 19.8% and +N = 26.6% average cover). The other species had lower than 10% cover. Significant differences of species percent cover between experimental groups (+N and −N) were detected in the annual analysis (p = 0.059). Seasonal analysis did not showed significant differences for any season. Monthly analysis showed significant differences in average percent cover when nutrients were added in eight species in different months: Bossiella orbigniana (August); Colpomenia sinuosa (June); Corallina officinalis (August); C. vancouveriensis (June); Dictyota flabellata (September); Eisenia arborea (June); Gracilaria marcialana (June); Macrocystis pyrifera (October), and the seagrass Phyllospadix torreyi (September and December). In conclusion, not all seaweed species are sensitive to nutrient addition during the ENSO years. In this research, we found eight species and one seagrass that had a positive reaction to the nutrients during the most severe stage (summer) of the ENSO.     

Epidemiological Trends of Dengue Disease in Mexico (2000–2011): A Systematic Literature Search and Analysis

This systematic literature review describes the epidemiology of dengue disease in Mexico (2000–2011). The annual number of uncomplicated dengue cases reported increased from 1,714 in 2000 to 15,424 in 2011 (incidence rates of 1.72 and 14.12 per 100,000 population, respectively). Peaks were observed in 2002, 2007, and 2009. Coastal states were most affected by dengue disease. The age distribution pattern showed an increasing number of cases during childhood, a peak at 10–20 years, and a gradual decline during adulthood. All four dengue virus serotypes were detected. Although national surveillance is in place, there are knowledge gaps relating to asymptomatic cases, primary/secondary infections, and seroprevalence rates of infection in all age strata. Under-reporting of the clinical spectrum of the disease is also problematic. Dengue disease remains a serious public health problem in Mexico.     

Boom means bust: interactions between the El Niño/Southern Oscillation (ENSO), rainfall and the processes threatening mammal species in arid Australia

We collated an environmental history for a 8580 km² study area in the Simpson Desert, Australia. Quantitative and qualitative data on climate, land-use, fire history and ecosystem dynamics were used to construct a chronology of processes threatening terrestrial mammal species. Over the last 150 years there has been the transition in land tenure from a hunter–gatherer economy to pastoralism, the loss of 11 mammal species, the cessation of small scale burning by Aboriginal people and the introduction of the fox and cat. Annual rainfall was highly variable and was influenced by the phase of the El Niño Southern Oscillation (ENSO). Irruptions of rodents, marked increases in the populations of native and introduced predators and extensive wildfires were associated with the La Niña phase of ENSO and occurred when rain-year (July–June) rainfall approached or exceeded the 90th percentile of the historical rainfall distribution. Large rainfall events in arid Australia have been viewed traditionally as the ‘boom’ times that benefit wildlife and pastoral production. However, because of hyper-predation and the risk of wildfire, we show that the years including and immediately following flooding rains should be identified as critical, or ‘bust’ periods for wildlife and conservation management. ENSO related climatic forecasts appear to be useful cues which can be incorporated into fire and predator management strategies in arid Australia. Studies such as this, which utilise a broad range of data types across extensive areas, can identify the timing and potential of threatening process not possible using contemporary studies alone.     

Short-Term Effect of El Ni?o-Southern Oscillation on Pediatric Hand,Foot and Mouth Disease in Shenzhen,China

Hand, foot and mouth disease (HFMD) was an emerging viral infectious disease in recent years in Shenzhen. The underlying risk factors have not yet been systematically examined. This study analyzed the short-term effect of El Niño-Southern Oscillation on pediatric HFMD in Shenzhen, China. Daily count of HFMD among children aged below 15 years old, Southern Oscillation Index (SOI), and weather variables were collected to construct the time series. A distributed lag non-linear model was applied to investigate the effect of daily SOI on pediatric HFMD occurrence during 2008–2010. We observed an acute effect of SOI variation on HFMD occurrence. The extremely high SOI (SOI = 45, with 0 as reference) was associated with increased HFMD, with the relative risk (RR) being 1.66 (95% Confidence Interval [CI]: 1.34–2.04). Further analyses of the association between HFMD and daily mean temperature and relative humidity supported the correlation between pediatric HFMD and SOI. Meteorological factors might be important predictors of pediatric HFMD occurrence in Shenzhen.     

Seasonal and El Niño Southern Oscillation-driven variations in isotopic and elemental patterns among estuarine primary producers: implications for ecological studies

Estuaries are complex systems where environmental fluctuations occur over distinct timescales due to local meteorological and large-scale climatic factors. Consequently, studies with low temporal resolution and taxonomic coverage may fail to detect isotopic variations in basal sources, providing biased interpretations of isotope mixing models. We investigated the seasonal and El Niño Southern Oscillation (ENSO)-driven interannual variations in δ¹³C, δ¹⁵N and C:N values among distinct basal sources and their implications for mixing models interpretation in a subtropical estuary. δ¹³C variations among sources differed in their magnitude and timescales, being large enough to confound source-specific values. Macroalgae and POM δ¹³C varied seasonally, whereas ENSO effects prevailed for C₃ and C₄ salt marsh plants, highlighting the contrasting influence of local versus remote environmental drivers on short- and long-lived primary producers, respectively. Peaks of δ¹⁵N were detected for all sources during short-term anthropogenic nutrient inputs. Isotope mixing model comparisons showed that overlooking isotopic variations in basal sources under distinct ENSO conditions can cause misinterpretation of local trophic interactions and nutrient cycling. The present study contributes to design appropriate sampling delineations in highly variable aquatic environments, emphasizing the importance of comprehensive, long-term monitoring of estuarine primary producers to encompass environmental drivers of stable isotopic variations.

     

Changes in the Cellular and Organismal Stress Responses of the Subtropical Fish, the Indo-Pacific Sergeant, Abudefduf vaigiensis, due to the 1997–1998 El Niño/Southern Oscillation

There are accumulating reports showing that the El Niño/Southern Oscillation (ENSO) has a significant effect on the population dynamics of marine fishes. However, the influence of ENSO on the physiology of fishes, as possible components of those ecological changes in fish populations, is not fully understood. This study investigated the cellular, physiological, and organismal stress responses in a wild fish population under natural thermal stress. The sea surface temperature at the subtropical ocean of Okinawa, Japan, was the highest in the last 10 years (>32°C) during the summer of 1998 with a strong ENSO. To examine the effects of those unusually warm ocean temperatures on fish, we compared tissue 70-kDa heat shock protein (HSP70) levels and growth rates between the ENSO summer of 1998 and the normal summer of 1999 in a common fish species in Okinawa, the Indo-Pacific sergeant, Abudefduf vaigiensis. We also conducted a complementary heat shock experiment in the laboratory. The field collected Indo-Pacific sergeant had significantly higher muscle HSP70 levels in 1998 than 1999. Higher muscle HSP70 and plasma cortisol levels were observed at 32°C than at 28°C in the laboratory heat shock experiment, indicating that the highest summer ocean temperature in 1998 was sufficient for the fish to up-regulate the cellular and physiological stress responses. In support of this effect, otoliths showed slower growth rates of the fish during the summer of 1998; this may reflect the significant energetic cost of these stress responses.     

Climate,Livestock, and Vegetation: What Drives Fire Increase in the Arid Ecosystems of Southern Russia?

Fire is an important natural disturbance process in arid grasslands but current fire regimes are largely the result of both human and natural processes and their interactions. The collapse of the Soviet Union in 1991 spurred substantial socioeconomic changes and was ultimately followed by a rapid increase in burned area in southern Russia. What is unclear is whether this increase in burned area was caused by decreasing livestock numbers, vegetation changes, climate change, or interactions of these factors. Our research goal was to identify the driving forces behind the increase in burned area in the arid grasslands of southern Russia. Our study area encompassed 19,000 km² in the Republic of Kalmykia in southern Russia. We analyzed annual burned area from 1986 to 2006 as a function of livestock population, NDVI, precipitation, temperature, and broad-scale oscillation indices using best subset regressions and structural equation modeling. Our results supported the hypothesis that vegetation recovered within 5–6 years after the livestock declined in the beginning of the 1990s, to a point at which large fires could be sustained. Climate was an important explanatory factor for burning, but mainly after 1996 when lower livestock numbers allowed fuels to accumulate. Ultimately, our results highlight the complexity of coupled human-natural systems, and provide an example of how abrupt socioeconomic change may affect fire regimes.     

Changes in the Status of Lophura Pheasants in Khao Yai National Park,Thailand: A Response to Warming Climate?

Long-term bird population changes in response to natural or anthropogenic factors have been relatively well documented in the temperate zone, but rarely in the tropics, where there are few long-term data sets. Here, we analyze a 25-yr sequence of records of two species of Lophura pheasants, Siamese Fireback L. diardi and Silver Pheasant L. nycthemera in Khao Yai, Thailand's oldest national park. These data suggest that the number and proportion of detections of the lowlands-inhabiting L. diardi have increased significantly in relation to those of the higher elevation inhabitant L. nycthemera . Environmental factors mediated by changing climate are the most plausible explanation for the changing proportions of sightings of the two species. Further work is needed to explore in detail microhabitat selection of these birds and whether changes in microsite conditions on the forest floor or other factors are driving the observed distribution. Long-term monitoring of the avifauna along an elevational gradient is also recommended in tandem with increased monitoring of local climatic conditions.     

<Emphasis Type="Italic">Isla Evangelista—</Emphasis>A Story of Church and State: Puerto Rico’s Faith-Based Initiatives in Drug Treatment

This article describes the debates leading to Puerto Rico’s Mental Health Law of 2000, which defined addiction as a spiritual and social problem rather than a mental disorder, in order to trace three competing approaches to addiction in Puerto Rico: evangelist, biomedical, and harm-reductionist. Highlighting the ways in which the evangelist approach of Puerto Rican street ministries challenges the individualism underlying US faith-based initiatives and the punitive approach of the US War on Drugs, this article concludes that the virtues of the evangelist approach to addiction would be best supported by public funding for biomedical and harm-reduction approaches within a pluralistic system of treatment for addiction.     

A Blessing and a Curse? Political Institutions in the Growth and Decay of Generalized Trust: A Cross-National Panel Analysis, 1980–2009

Despite decades of research on social capital, studies that explore the relationship between political institutions and generalized trust-a key element of social capital-across time are sparse. To address this issue, we use various cross-national public-opinion data sets including the World Values Survey and employ pooled time-series OLS regression and fixed- and random-effects estimation techniques on an unbalanced panel of 74 countries and 248 observations spread over a 29-year time period. With these data and methods, we investigate the impact of five political-institutional factors-legal property rights, market regulations, labor market regulations, universality of socioeconomic provisions, and power-sharing capacity-on generalized trust. We find that generalized trust increases monotonically with the quality of property rights institutions, that labor market regulations increase generalized trust, and that power-sharing capacity of the state decreases generalized trust. While generalized trust increases as the government regulation of credit, business, and economic markets decreases and as the universality of socioeconomic provisions increases, both effects appear to be more sensitive to the countries included and the modeling techniques employed than the other political-institutional factors. In short, we find that political institutions simultaneously promote and undermine generalized trust.