Evidence-based policymaking: Lessons from the Chilean Substance Use Treatment Policy

Background: Evidence-based policymaking is a guiding paradigm of substance use treatment (SUT) policy, that seeks to prioritise scientific criteria over other concerns (e.g., economic, political) when addressing policy decisions. We provide a comprehensive analysis of the context and mechanisms that enable and constrain evidence to improve the Chilean SUT policy and draw some lessons that might be useful to other contexts, particularly low and middle-income countries. Methods: This study relied on an interpretive case study design based on the principles of realist evaluation. We included interviews (N≈17) with international, national, regional, and local policymakers and experts, as well as technical and clinical teams from private and public care SUT providers in Chile. Results: Complex sets of institutional realities and notions of ‘evidence’ shared by actors - between other elements- guide the SUT policy decisions and shape the specific type of evidence considered relevant. Evidence is understood in Chile in narrow terms, and national non-experimental research is often overlooked. This limits the possibility of studying other research questions that could contribute to improving and informing SUT policy. Conclusions: In contexts where addiction research resources are limited, it appears necessary to re-frame the notion of "evidence", to consider relevant national non-experimental knowledge to strengthen SUT policy and achieve its goals. Indeed, this study is an example of how methodological approaches, such as case analysis, can provide a powerful heuristic alternative contribution to the local and global mental health debate.No Full Tex

Environmental variability and larval supply to wild and cultured shellfish populations

Coastal upwelling ecosystems support some of the most productive fisheries of the planet together with a large shellfish aquaculture sector that depends on oceanographic processes to deliver planktonic larvae to replenish and feed the farmed stock. Coastal shellfish aquaculture operations in Chile and Peru have experienced large interannual fluctuations in larval supply over the past decade, yet the drivers of such variability remain unidentified. We focused on the effects of environmental variability on larval supply of the farmed Peruvian bay scallop Argopecten purpuratus in a bay in northern Chile (Tongoy Bay, 30 circle S) that accounts for over 90% of countrywide landings. We examined the hypothesis that the environmental processes governing larval supply were shared with wild benthic invertebrates with planktonic larval development and compared time series of larval abundance for the scallop with larval supply rates to benthic populations of two well-studied wild intertidal species: the Chthamalid barnacle Jehlius cirratus and the purple mussel Perumytilus purpuratus. To this end, we examined the cross-correlation of larval supply to environmental variability using MODIS satellite fields of sea surface temperature (SST) chlorophyll-a concentration (chl-a) and fluorescence line height (nFLH), together with three climate indices relevant for the south east Pacific sector: the Southern Oscillation index (SOI), the Pacific Decadal Oscillation (PDO) and the Antarctic Oscillation Index (AAO). Our results showed that over the five-year study period (2009-2013), patterns of larval supply to the scallop population were related to interannual variability in the environmental processes as captured by their Empirical Orthogonal Functions (EOFs), likely to adult condition before spawning. Surprisingly, larval supply for none of the wild species showed a clear association to the EOFs. In contrast, scallops and wild species showed significant association to lower frequency climate variability as captured by the SOI and the PDO, but not the AAO. Results suggest that larval supply patterns to Tongoy Bay may be modulated by regional patterns of climatic variability, particularly of tropical origin. Thus, changes in coastal oceanography associated with ongoing changes in global climate could have strong and lasting effects on the supply of seedstock for wild and cultivated species across this eastern boundary coastal system and argue for the establishment of long-term ocean observing and early warning systems along the region

Improving the underground structural characterization and hydrological functioning of an Andean peatland using geoelectrics and water stable isotopes in semi-arid Chile

High altitude, Andean wetlands, or bofedales as they are locally known, are important regulators of the local water balance and also play a key role in sustaining biodiversity. Nevertheless, there is almost no information regarding their hydrogeological structure and functioning. This paper aims to characterize the thickness of the alluvial filling of one peat-accumulating wetland in North-Central Chile using Electrical Resistivity Tomography (ERT) to assess its role as a water reservoir. To develop a quasi-3D understanding of the peatland’s structure, four ERT profiles were conducted. Results highlight a conductive basin shape of the peatland, with a thicker interface downstream than upstream between alluvial materials and the underlying bedrock or rock screes. Those results allow the estimate of the water column (1000–3400 mm) within the peatland alluvial filling. The second objective is to better understand the water exchanges between the peatland and the streamflow using discharge measurements and water stable isotopes. Water and isotopes budgets highlight a streamflow loss towards the peatland groundwater reservoir at the end of spring season. In addition, ten δ¹⁸O and δ²H surveys were used to characterize the distinct wetland water sources and their temporal variations. A peatland conceptual model is proposed to connect groundwater, rock glaciers, snowmelt, and hillslope flows. Andean peatlands provide a pivotal control on water delivery downstream, and therefore, understanding their structure and function is important, because they are unique structures providing ecological services at high elevations