Toxicity of five antidepressant drugs on embryo–larval development and metamorphosis success in the Pacific oyster,Crassostrea gigas

Unlike conventional pollutants, pharmaceutical residues are continuously discharged at low levels (low to mid ng l^?1 concentrations), which results in the chronic contamination of non-target organisms, but little is known about the effects of these residues. The purpose of this study was to provide the first assessment of the ecotoxicity of five antidepressants (selective serotonin reuptake inhibitors [SSRIs] fluoxetine and sertraline, tricyclic antidepressants [TCAs] clomipramine and amitriptyline, and serotonin norepinephrine reuptake inhibitor [SNRI] duloxetine) at a wide range of concentrations from 0.1 to 100,000 μg l^?1 on two early life stages in the Pacific oyster. The toxicity was quantified in D-shaped larvae after 36 h of exposure, and in 21-day-old pediveliger larvae after 24 h of exposure using the percentage of normal larval development and the metamorphosis rate as endpoints, respectively. The embryotoxicity assays reported that the EC₅₀ values were within the same range of concentrations (67 to 192 μg l^?1) for all of the tested molecules. The metamorphosis tests revealed that the antidepressants can be ranked along an increasing severity gradient: clomipramine < amitriptyline < duloxetine ~ fluoxetine. Sertraline appeared to be the less toxic molecule on this endpoint; however, a different concentration range was used. The embryotoxicity test was more sensitive than the metamorphosis bioassay for three of the five molecules tested, but the latter test showed more practical benefits. Overall, the obtained toxicity values were at least 10,000-fold higher than the reported environmental concentrations.     

Deliberation and Scale in Mekong Region Water Governance

Understanding the politics of deliberation, scales, and levels is crucial to understanding the social complexity of water-related governance. Deliberative processes might complement and inform more conventional representational and bureaucratic approaches to planning and decision-making. However, they are also subject to scale and level politics, which can confound institutionalized decision-making. Scale and level contests arise in dialogues and related arenas because different actors privilege particular temporal or spatial scales and levels in their analysis, arguments, and responses. Scale contests might include whether to privilege administrative, hydrological, ecosystem, or economic boundaries. Level contests might include whether to privilege the subdistrict or the province, the tributary watershed or the international river basin, a river or a biogeographic region, and the local or the regional economy. In the Mekong Region there is a recurrent demand for water resources development projects and major policies proposed by governments and investors to be scrutinized in public. Deliberative forms of engagement are potentially very helpful because they encourage supporters and critics to articulate assumptions and reasoning about the different opportunities and risks associated with alternative options, and in doing so, they often traverse and enable higher-quality conversations within and across scales and within and between levels. Six case studies from the Mekong Region are examined. We find evidence that scale and level politics affects the context, process, content, and outcomes of deliberative engagement in a region where public deliberation is still far from being a norm, particularly where there are sensitive and far-reaching choices to be made about water use and energy production.     

Aquaculture farmers’ perceptions of climate-related risks in the Mekong Region

Natural protected areas (NPA) are portions of the Mexican territory where the original environment has not been modified and which are protected in order t     

Long-term recovery narratives following major disasters in Southeast Asia

Regional Environmental Change - Most studies of major disasters focus on the impacts of the event and the short-term responses. Some evaluate the underlying causes of vulnerability, but few...     

Learning about climate-related risks: decisions of Northern Thailand fish farmers in a role-playing simulation game

River-based cage aquaculture in Northern Thailand involves dealing with a number of climate- and weather-related risks. The purpose of this study was to improve understanding of how farmers make investment decisions in their fish farms when faced with risks from floods that are imperfectly known, and which may be changing. A role-playing simulation game was created to capture some of the key features of the decision-making context and explored with farmers in the field. In-depth interviews were conducted post-game to reflect on strategies used in the game as compared to in practice. As hypothesized, more frequent or larger impact floods reduced cumulative profits. Farmers reduced their stocking densities when playing in games with high likelihood of floods, but did not do so in games with large impacts when a flood occurred. Contrary to initial expectations, farmers were less likely to learn from experience—choose the optimal density and thus improve score within a game—when floods were common or had large impacts. Farmers learnt most when risks were decreasing and least when they were increasing. Providing information about likelihoods prior to a game had no impact on performance or decisions. The methods and findings of this study underline the importance of understanding decision-making behaviour around risks for climate risk management. The novel combination of experimental, role-playing, and qualitative methods revealed limitations in common assumptions about the ease of learning about risks from previous experiences. The findings also suggest that decision-support systems for aquaculture need to take into account how recent experiences, understanding of information, and other factors influence risk perceptions and decisions.     

Local knowledge and adaptation to climate change in natural resource-based societies of the Asia-Pacific

This paper reviewed 42 studies of how local knowledge contributes to adaptation to climate and climate change in the Asia-Pacific Region. Most studies focused on traditional ecological or indigenous knowledge. Three simple questions were addressed: (1) How are changes in climate recognized? (2) What is known about how to adapt to changes in climate? (3) How do people learn about how to adapt? Awareness of change is an important element of local knowledge. Changes in climate are recognized at multiple time scales from observations that warn of imminent extreme weather through expectations for the next season to identification of multi-year historical trends. Observations are made of climate, its impact on physical resources, and bio-indicators. Local knowledge about how to adapt can be divided into four major classes: land and water management, physical infrastructure, livelihood strategies, and social institutions. Adaptation actions vary with time scale of interest from dealing with risks of disaster from extreme weather events, through slow onset changes such as seasonal droughts, to dealing with long-term multi-year shifts in climate. Local knowledge systems differ in the capacities and ways in which they support learning. Many are dynamic and draw on information from other places, whereas others are more conservative and tightly institutionalized. Past experience of events and ways of learning may be insufficient for dealing with a novel climate. Once the strengths and limitations of local knowledge (like those of science) are grasped the opportunities for meaningful hybridization of scientific and local knowledge for adaptation expand.     

Local Irrigation Management Institutions Mediate Changes Driven by External Policy and Market Pressures in Nepal and Thailand

This article assesses the role of local institutions in managing irrigation water use. Fifty irrigation systems in each country were studied in Nepal and Thailand to compare the influence of local institutions on performance of irrigation systems amid changes in external policy and market pressures. Nepal’s new irrigation policy after the re-instatement of multiparty democracy in 1990 emphasized participatory irrigation management transferring the management responsibility from state authorities to water users. The water user associations of traditional farmer-managed irrigation systems were formally recognized by requiring registration with related state authorities. In Thailand also government policies encouraged people’s participation in irrigation management. Today water users are directly involved in management of even some large irrigation systems at the level of tertiary canals. Traditional communal irrigation systems in northern Thailand received support for system infrastructure improvement but have faced increased interference from government. In Thailand market development supported diversification in farming practices resulting in increased areas under high water-demanding commercial crops in the dry season. In contrast, the command areas of most irrigation systems in Nepal include cereal-based subsistence farming with only one-third having commercial farming. Cropping intensities are higher in Nepal than in Thailand reflecting, in part, differences in availability of land and management. In both countries local institutions play an important role in maintaining the performance of irrigation systems as external drivers and local contexts change. Local institutions have provided alternative options for irrigation water use by mediating external pressures.     

Institutional traps and vulnerability to changes in climate and flood regimes in Thailand

Vulnerabilities to floods in Thailand are changing as a result of many factors. Formal and informal institutions help shape exposure, sensitivity and capacities to respond of individuals, social groups and social-ecological systems. In this paper we draw on several case studies of flood events and flood-affected communities to first assess how current practices reflect various laws, procedures, programs and policies for managing floods and disasters and then explore the implications for dealing with additional challenges posed by climate change. Our analysis identifies several institutional traps which need to be overcome if vulnerability is to be reduced, namely capture of agendas by technical elites, single-level or centralized concentration of capacities, organizational fragmentation and overemphasis on reactive crisis management. Possible responses are to expand public participation in managing risks, build adaptive capacities at multiple levels and link them, integrate flood disaster management and climate change adaptation into development planning, prioritize risk reduction for socially vulnerable groups and strengthen links between knowledge and practice. Responses like these could help reduce vulnerabilities under current climate and flood regimes, while also improving capacities to handle the future which every way that unfolds.     

Formation of halogenated acetaldehydes, and occurrence in Canadian drinking water

Controlled laboratory chlorination of acetaldehyde (ACD) under typical drinking water conditions (pH 6.7, 7.6 and 8.8, and temperature 4 degrees C and 21 degrees C) revealed that the formation of chloral hydrate (CH), the most common halogenated acetaldehyde (HAs), increased with contact time (0-10 days). However, at increased pH and temperature, CH reached maximum levels and subsequently broke down partially to chloroform and other unidentified compounds. After 10 days contact time, a maximum of 63% (molar) of the initial ACD consumed were converted into CH or chloroform (TCM). Various surveys of drinking water systems indicated that ACD is not the only precursor of CH. A suite of aldehydes (including ACD), and chlorinated disinfection by-products (including TCM and CH) were found in most distribution systems. The levels of bromide in source water impacted speciation of HAs. In addition to CH, brominated and other mixed (Cl/Br) acetaldehydes were detected in most samples; the speciation of HAs and THMs followed comparable trends. Similar to chloroform for trihalomethanes, CH contributed from as low as 5% to up to 60% of the total HAs. The bromine incorporation factors (BIF) in THMs and HAs were shown to increase with increasing bromide ion concentrations in the source water. Brominated THMs are more readily formed than their HA analogues; in fact, BIF values for THMs were 2-3 times higher than for the HAs. It was found that HAs may be as high as THMs in some drinking waters. As a result, the determination of the other target HAs, in addition to CH, is necessary for a better assessment of the pool of disinfection by-products in drinking water.