Sources and microbiological quality of domestic water in three rural communities in the southern Caribbean.

This study investigated the sources and microbiological quality of domestic water used by rural communities of Speightstown, Barbados; Carriacou, Grenada; and Nariva, Trinidad. The primary water source was harvested rainwater in Carriacou, and the public water supply for Nariva and Speightstown. Secondary water supplies of the communities came from untreated sources including rainwater, wells, boreholes and springs. E. coli was detected at higher frequencies in water from Carriacou (41.3%) and Nariva (47.4%) than Speightstown (3.6%). Generally, more untreated samples of rainwater (44.6%) and surface/ground water (58.3%) were E. coli positive than treated water obtained from the public supply (9.9%). These findings demonstrate the increased risk to residents in rural communities of the Caribbean who utilize untreated rainwater and environmental sources such as springs and wells. These results demonstrate the usefulness of traditional methods such as the compartment bag test in determining the microbiological quality of domestic water in resource-challenged rural communities of the Caribbean.

Science for managing ecosystem services: Beyond the Millennium Ecosystem Assessment.

The Millennium Ecosystem Assessment (MA) introduced a new framework for analyzing social-ecological systems that has had wide influence in the policy and scientific communities. Studies after the MA are taking up new challenges in the basic science needed to assess, project, and manage flows of ecosystem services and effects on human well-being. Yet, our ability to draw general conclusions remains limited by focus on discipline-bound sectors of the full social-ecological system. At the same time, some polices and practices intended to improve ecosystem services and human well-being are based on untested assumptions and sparse information. The people who are affected and those who provide resources are increasingly asking for evidence that interventions improve ecosystem services and human well-being. New research is needed that considers the full ensemble of processes and feedbacks, for a range of biophysical and social systems, to better understand and manage the dynamics of the relationship between humans and the ecosystems on which they rely. Such research will expand the capacity to address fundamental questions about complex social-ecological systems while evaluating assumptions of policies and practices intended to advance human well-being through improved ecosystem services.

Influence of Climatic Factors on Human Hantavirus Infections in Latin America and the Caribbean: A Systematic Review.

BACKGROUND: With the current climate change crisis and its influence on infectious disease transmission there is an increased desire to understand its impact on infectious diseases globally. Hantaviruses are found worldwide, causing infectious diseases such as haemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS)/hantavirus pulmonary syndrome (HPS) in tropical regions such as Latin America and the Caribbean (LAC). These regions are inherently vulnerable to climate change impacts, infectious disease outbreaks and natural disasters. Hantaviruses are zoonotic viruses present in multiple rodent hosts resident in Neotropical ecosystems within LAC and are involved in hantavirus transmission. METHODS: We conducted a systematic review to assess the association of climatic factors with human hantavirus infections in the LAC region. Literature searches were conducted on MEDLINE and Web of Science databases for published studies according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria. The inclusion criteria included at least eight human hantavirus cases, at least one climatic factor and study from > 1 LAC geographical location. RESULTS: In total, 383 papers were identified within the search criteria, but 13 studies met the inclusion criteria ranging from Brazil, Chile, Argentina, Bolivia and Panama in Latin America and a single study from Barbados in the Caribbean. Multiple mathematical models were utilized in the selected studies with varying power to generate robust risk and case estimates of human hantavirus infections linked to climatic factors. Strong evidence of hantavirus disease association with precipitation and habitat type factors were observed, but mixed evidence was observed for temperature and humidity. CONCLUSIONS: The interaction of climate and hantavirus diseases in LAC is likely complex due to the unknown identity of all vertebrate host reservoirs, circulation of multiple hantavirus strains, agricultural practices, climatic changes and challenged public health systems. There is an increasing need for more detailed systematic research on the influence of climate and other co-related social, abiotic, and biotic factors on infectious diseases in LAC to understand the complexity of vector-borne disease transmission in the Neotropics.

Pervasive human-driven decline of life on Earth points to the need for transformative change.

The human impact on life on Earth has increased sharply since the 1970s, driven by the demands of a growing population with rising average per capita income. Nature is currently supplying more materials than ever before, but this has come at the high cost of unprecedented global declines in the extent and integrity of ecosystems, distinctness of local ecological communities, abundance and number of wild species, and the number of local domesticated varieties. Such changes reduce vital benefits that people receive from nature and threaten the quality of life of future generations. Both the benefits of an expanding economy and the costs of reducing nature's benefits are unequally distributed. The fabric of life on which we all depend-nature and its contributions to people-is unravelling rapidly. Despite the severity of the threats and lack of enough progress in tackling them to date, opportunities exist to change future trajectories through transformative action. Such action must begin immediately, however, and address the root economic, social, and technological causes of nature's deterioration.

Biodiversity and ecosystem services require IPBES to take novel approach to scenarios.

What does the future hold for the world's ecosystems and benefits that people obtain from them? While the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) has identified the development of scenarios as a key to helping decision makers identify potential impacts of different policy options, it currently lacks a long-term scenario strategy. IPBES will decide how it will approach scenarios at its plenary meeting on 22-28 February 2016, in Kuala Lumpur. IPBES now needs to decide whether it should create new scenarios that better explore ecosystem services and biodiversity dynamics. For IPBES to capture the social-ecological dynamics of biodiversity and ecosystem services, it is essential to engage with the great diversity of local contexts, while also including the global tele-coupling among local places. We present and compare three alternative scenario strategies that IPBES could use and then suggest a bottom-up, cross-scale scenario strategy to improve the policy relevance of future IPBES assessments. We propose five concrete steps as part of an effective, long term scenario development process for IPBES in cooperation with the scientific community.

Application of toxicity identification evaluation procedures for characterizing produced water using the tropical mysid, Metamysidopsis insularis.

Toxicity identification evaluations (TIEs) were performed on seven produced water (PW) effluents from inland discharge facilities operated in Trinidad and Tobago, a Caribbean tropical country with one of the oldest commercial oil industries in the world. The research was performed to determine the presence and magnitude of toxicity and characterize which toxicants are responsible for observed effects. Marine effluent toxicity characterizations with Metamysidopsis insularis revealed high whole acute toxic-unit response for produced water ranged from 8.1 to > 17.0 acute toxic-unit (initial toxicity test) and 5.7 to 1,111 acute toxic-unit (baseline toxicity test). Toxicity test results for all sites except one, which had the highest toxicity, are comparative with similar studies on produced water. The toxicological causality of this complex mixture differed for each PW with nonpolar organics being consistently toxic in all samples. Other potential toxicants contributing to overall toxicity to a much lesser extent were metals, ammonia, and volatile organic compounds. With the use of sodium thiosulfate and filtration manipulations for only PW6 sample, there was very slight reduction in toxicity; therefore, oxidants and filterable materials were not a great contributing factor. Whole effluent toxicity also can be attributed to ionic imbalance and the very stable oil-in-water emulsion that consists of fine oil droplets (less than 0.1-10 microm with an average diameter of 2.5 microm). This investigation is the first of its type in Trinidad and demonstrates clearly the applicability of this test method and local test species for evaluating complex effluents in tropical environments.

The occurrence of NADPH-ferrihemoprotein reductase in Corbula caribea, from a natural oil seep at La Brea, Trinidad.

Corbula caribea is the most common non-polychaete macrofaunal organism identified at a large natural oil seep at La Brea in south Trinidad. It is hypothesized that these animals may possess (NADPH-ferrihemoprotein reductase) a component of the Mixed Function Oxygenase system (MFO), which may allow them to ameliorate the potentially deleterious effects resulting from exposure to the high levels of petroleum hydrocarbons within this environment. This study was designed to determine whether organisms from the seep site showed greater enzyme activity when compared to organisms from a non-seep reference site. NADPH-ferrihemoprotein reductase activity was determined by incubating 10 microm cryostat sections with nitro-blue tetrazolium. The reaction product was determined by visual assessment and quantified by measuring the relative mean stain intensity. The intense staining, indicative of enzyme activity was evident in the digestive epithelia of seep animals. Observations indicated that organisms from the seep showed more intense staining, indicating greater enzyme activity, when compared to animals from a non-seep reference site. The relative stain intensity of NADPH-ferrihemoprotein reductase determined for organisms from the seep was 61.30. This was significantly higher than the stain intensity determined for organisms from the non-seep reference site (7.11). This supported visual assessments, which suggested that the seep organisms showed higher enzyme activity than organisms from the non-seep site. The results suggest that NADPH-ferrihemoprotein reductase may be present in Corbula caribea from the seep site and not in those from the non-seep site. It is possible that this enzyme may contribute to these animals ability to tolerate chronic exposure to petroleum hydrocarbons and offer then a selective advantage for survival the seep environment.

Exploratory space-time analysis of dengue incidence in Trinidad: a retrospective study using travel hubs as dispersal points, 1998-2004.

BACKGROUND: Dengue is an acute arboviral disease responsible for most of the illness and death in tropical and subtropical regions. Over the last 25 years there has been increase epidemic activity of the disease in the Caribbean, with the co-circulation of multiple serotypes. An understanding of the space and time dynamics of dengue could provide health agencies with important clues for reducing its impact. METHODS: Dengue Haemorrhagic Fever (DHF) cases observed for the period 1998-2004 were georeferenced using Geographic Information System software. Spatial clustering was calculated for individual years and for the entire study period using the Nearest Neighbor Index. Space and time interaction between DHF cases was determined using the Knox Test while the Nearest Neighbor Hierarchical method was used to extract DHF hot spots. All space and time distances calculated were validated using the Pearson r significance test. RESULTS: Results shows that (1) a decrease in mean distance between DHF cases correlates with activity leading up to an outbreak, (2) a decrease in temporal distance between DHF cases leads to increased geographic spread of the disease, with an outbreak occurrence about every 2 years, and (3) a general pattern in the movement of dengue incidents from more rural to urban settings leading up to an outbreak with hotspot areas associated with transportation hubs in Trinidad. CONCLUSION: Considering only the spatial dimension of the disease, results suggest that DHF cases become more concentrated leading up to an outbreak. However, with the additional consideration of time, results suggest that when an outbreak occurs incidents occur more rapidly in time leading to a parallel increase in the rate of distribution of the disease across space. The results of this study can be used by public health officers to help visualize and understand the spatial and temporal patterns of dengue, and to prepare warnings for the public. Dengue space-time patterns and hotspot detection will provide useful information to support public health officers in their efforts to control and predict dengue spread over critical hotspots allowing better allocation of resources.

Metals in sediments and fish from Sea Lots and Point Lisas Harbors, Trinidad and Tobago.

Concentrations of heavy metals were determined in nearshore marine sediments and fish tissue from Sea Lots area on the west coast, at Caroni Lagoon National Park, and in the Point Lisas harbor, Trinidad. The most dominant metals found in sediments were Al, Fe and Zn with mean concentrations highest at Sea Lots (Al-39420 µg/g; Fe-45640 µg/g; Zn-245 µg/g), when compared to sediments from Point Lisas (Al-11936 µg/g; Fe-30171 µg/g; Zn-69 µg/g) and Caroni (Al-0400 µg/g; Fe-19000 µg/g; Zn-32 µg/g), High concentration of Cu, Al, Fe and Zn were also detected in fish tissue from Point Lisas and Caroni. Metal concentrations in fish tissue showed significant correlation with sediment metals concentration, which suggests that tissue levels are influenced by sediment concentration. Of the metals, only Zn, Hg and Cu had a bioaccumulation factor (BAF) greater than one, which suggests a high bioaccumulation potential for these metals.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in harbor sediments from Sea Lots, Port-of-Spain, Trinidad and Tobago.

Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in nearshore marine surficial sediments from three locations in Trinidad. Sediments were sampled at Sea Lots on the west coast, in south Port-of-Spain Harbor, south of Sea Lots at Caroni Lagoon National Park, and on Trinidad's east coast at Manzanilla. Total PCB concentrations in Sea Lots sediments ranged from 62 to 601ng/g (dry weight {dw}), which was higher than at Caroni and Manzanilla, 13 and 8ng/g dw, respectively. Total OCP concentrations at Sea Lots were ranged from 44.5 to 145ng/g dw, compared with 13.1 and 23.8n/g (dw), for Caroni and Manzanilla respectively. The concentrations of PCBs and of some OCPs in sediments from Sea Lots were above the Canadian interim sediment quality guidelines. To date, this data is the first report on the levels of PCBs and other organochlorine compounds from Trinidad and Tobago.

Comparative salinity tolerance of three indigenous tropical freshwater cladoceran species; Moinodaphnia macleayi, Ceriodaphnia rigaudii and Diaphanosoma brachyurum.

The acute salinity tolerance of three tropical freshwater cladoceran species, M. macleayi, C. rigaudii and D. brachyurum was determined. The existence of these species represented new records for Trinidad and Tobago, a tropical Caribbean island. It has a large oil based industry, in which, the primary effluent (saline produced water) is discharged directly into many freshwater systems. Cladoceran species are used routinely in temperate regions, to assess the impacts of chemicals and effluents in freshwater systems. However, relatively few studies have assessed the salinity tolerance of these organisms. Test organisms were assayed using seven salinity treatments (0, 1, 3, 5, 10, 15, 20, 25 per thousand) prepared by volumetrically mixing natural filtered seawater with dilution water. C. rigaudii had a 48 h LC50 of 1.6 per thousand, M. macleayi 1.5 per thousand and D. brachyurum <1 per thousand. The CSmax (critical salinity maximum) for C. rigaudii and M. macleayi was 3 per thousand after 48 h, compared to 1 per thousand for D. brachyurum. There was no salinity value at which there was 100% survival. The resulting salinity response curve was a straight line which indicated that each species was intolerant of salt. Consequently, any of these can be considered as a representative freshwater organism for toxicity testing in Trinidad and Tobago.

Comparative sensitivity of three tropical cladoceran species (Diaphanosoma brachyurum, Ceriodaphnia rigaudii and Moinodaphnia macleayi) to six chemicals.

The toxicities of six chemicals (cadmium chloride, potassium dichromate, sodium dodecyl sulfate, potassium chloride, Tritox X-100 and copper (II) sulphate) was determined for three tropical freshwater cladoceran, Moinodaphnia macleayi, Ceriodaphnia rigaudii and Diaphanosoma brachyurum. The data was subsequently used to compare the relative sensitivity of the three species. Relative sensitivities were determined by comparing the 48-hour LC50 values using an independent t-test and interspecies correlation. Potassium dichromate was the most toxic compound tested, while potassium chloride was the least toxic to all three species. The 48 h LC50 values for D. brachyurum ranged from 0.003 mg/L to 30.4 mg/L; M. macleayi LC50 values ranged from 0.003 mg/L to 30.1 mg/L whereas for C. rigaudii the values ranging between 0.002 mg/L to 21.1 mg/L. The LC50 values for C. rigaudii was significantly less (P < 0.05) than M. macleayi for five of the compounds tested, whereas for D. brachyurum it was significantly (P < 0.05) less than four of the compounds tested. The interspecies correlation also suggested that C. rigaudii and M. macleayi were more similar in sensitivity (R2 = 0.96) to each other than D. brachyurum (R2 = 0.91 with M. macleayi, and R2 = 0.87 with C. rigaudii).