Coastal Ecuador Research Articles

Octocoral Distribution Patterns at the Equatorial Front (Tropical Eastern Pacific): Muricea and Leptogorgia

The Equatorial Front, in the southern part of the Tropical Eastern Pacific (TEP) region, has been characterized as a hotspot of functional biodiversity due to the mixing of warm and cold waters. Nevertheless, the biogeographic patterns for some organisms, such as octocorals, remain unknown in some coastal regions. Therefore, we aimed to assess the distribution of two common octocoral genera in this area, Muricea and Leptogorgia, including 14 species based on museum specimen records, along the mainland coast of Ecuador. Statistical analyses were performed on the environmental and geographical patterns (Sea Surface Temperature (SST), bathymetry, chlorophyll (CHL-a), and Photosynthetic Active Radiation (PAR)) that influence the Equatorial Front, which is subdivided into five biogeographic regions. Our results showed two hotspots of octocoral biodiversity. The SST was found to be the main environmental factor related to octocoral distribution along the Equatorial Front. Finally, the highest abundance of Muricea over Leptogorgia suggests the former species’ higher resilience to thermal fluctuations. We discuss the possible role of substrates at suitable depths, active photosynthetic radiation, and temperature in the occurrence of octocorals in the two hotspots.

Dietary oily fish intake and progression of diffuse subcortical damage of vascular origin: A longitudinal prospective study in community-dwelling older adults.

Oily fish intake may reduce the progression of white matter hyperintensities (WMH) of presumed vascular origin due to their high content of omega-3 polyunsaturated fatty acids and other nutrients. However, information on this relationship is limited. We aimed to assess the association between oily fish intake and WMH progression in older adults living in rural coastal Ecuador. Participants of the Atahualpa Project Cohort received baseline clinical interviews and brain MRIs. Oily fish intake was calculated at every annual door-to-door survey from enrollment to the end of the study. Individuals who also received a follow-up brain MRI were included. Poisson regression models were fitted to assess the incidence rate ratio (IRR) of WMH progression according to the amount of oily fish intake, after adjusting for demographics, level of education and traditional vascular risk factors. The study included 263 individuals of Amerindian ancestry aged ⩾60 years (mean age: 65.7 ± 6.2 years; 57% women). The mean oily fish intake was 8.3 ± 4 servings per week. Follow-up MRIs demonstrated WMH progression in 103 (39%) individuals after a median follow-up of 6.5 years. A multivariate Poisson regression model showed an inverse relationship between oily fish intake and WMH progression (IRR: 0.89; 95% CI: 0.84-0.95; p < 0.001). A similar model also revealed an inverse relationship between tertiles of oily fish intake and probabilities of WMH progression, which became significant when individuals allocated to the third tertile were compared to those in the first and second tertiles. Study results show an inverse relationship between the amount of oily fish intake and WMH progression in frequent fish consumers of Amerindian ancestry.

Nasal cartilage destruction associated to cutaneous histoplasmosis in AIDS

BackgroundSystemic histoplasmosis is a disease of high morbidity and mortality in immunocompromised patients. Patients with AIDS get the infection through inhalation of spores, triggering a primary lung infection with a subsequent hematogenous spread to multiple organs, including the skin. Tissue necrosis have been documented in cutaneous histoplasmosis with multiple clinical manifestations that mimic other diseases.Case presentationWe report the case of nasal cartilage destruction associated to cutaneous histoplasmosis in AIDS. A 24-year-old man, resident in Ecuadorian coast, with a history of HIV for 7 years without any treatment. In the last 3 months, he has been presenting a molluscum-like lesions on his nasal bridge with subsequent dissemination to the trunk and extremities. He was admitted to the emergency department for dyspnoea, cough, and malaise. Due to his respiratory failure, he was admitted to the intensive care unit (ICU) with mechanical ventilation. Physical examination reveals a crusted surface ulcer that involves the nose and cheeks, associated with erythematous papules, some with a crusted surface which are spread to the face, trunk, and upper limbs. The patient has a specific skin involvement with a butterfly-like ulcer appearance and destruction of the upper and lower lateral cartilage of the nose. At admission CD4 cell count was 11/mm3 with a HIV viral load of 322,908 copies. Mycological cultures identified Histoplasma capsulatum. A treatment with highly active antiretroviral therapy (HAART) was stablished, associated with liposomal amphotericin B at a dose of 3 mg/kg/day and itraconazole 200 mg twice a day for 12 months.ConclusionsCutaneous histoplasmosis is a rare manifestation of pulmonary histoplasmosis in patients with AIDS. The cutaneous manifestations included papules, nodules, plaques, and ulcers. A histology examination is required to rule out other fungal or parasitic infections. Treatment includes highly active antiretroviral therapy (HAART), amphotericin B liposomal and itraconazole, the latest for at least 12 months.

Dioscorea magnibracteata (Dioscoreaceae), a new species from western Ecuador based on the unpublished work of Temple Clayton

Dioscorea magnibracteata is described and formally presented as a new species based on specimens identified with unpublished names by Temple Clayton. This species occurs exclusively in the seasonally deciduous dry tropical forest of coastal Ecuador, a fairly threatened environment. This new species is monoecious and features staminate flowers with six stamens but differs markedly from all other species of Neotropical Dioscorea by the staminate inflorescences with very large cymbiform bracts and toothed to lacerated margin. We provide a morphological description as well as information on habitat, geographic distribution and taxonomic comments that include the morphological delimitation of the new species and similarities to other species of Dioscorea sect. Monadelpha.

Assessing Susceptibility to Soil Liquefaction Using the Standard Penetration Test (SPT)—A Case Study from the City of Portoviejo, Coastal Ecuador

The city of Portoviejo in coastal Ecuador was severely affected during the 16 April 2016, Pedernales earthquake (Mw 7.8). Various coseismic liquefaction phenomena occurred, inducing lateral spreading, sand boils, ground subsidence, and sinkholes in soils with poor geotechnical quality in the alluvial and alluvial–colluvial sedimentary environment. Therefore, the main aim of this study was to collect data from standard penetration tests (SPT) and shear velocity and exploratory trenches and to calculate the liquefaction potential index (LPI) by considering a corresponding seismic hazard scenario with an amax = 0.5 g. From these data, a liquefaction hazard map was constructed for the city of Portoviejo, wherein an Fs of 1.169 was obtained. It was determined that strata at a depth of between 8 and 12 m are potentially liquefiable. Our quantitative results demonstrate that the city of Portoviejo’s urban area has a high probability of liquefaction, whereas the area to the southeast of the city is less sensitive to liquefaction phenomena, due to the presence of older sediments. Our results are in accordance with the environmental effects reported in the aftermath of the 2016 earthquake.

Relationship between the Fungal Incidence, Water Activity, Humidity, and Aflatoxin Content in Maize Samples from the Highlands and Coast of Ecuador.

This study evaluated the fungal incidence through direct plating in Agar Dichloran Glycerol, and the presence of aflatoxins in maize samples from the Highlands and Coast of Ecuador by HPLC, investigating the influence of the temperature, altitude, water activity, and humidity of the collection regions on the maize samples’ contamination using Principal Components Analysis (PCA). The overall kernel infection by fungi was usually lower in samples from the Highlands, and no aflatoxins or Aspergillus series Flavi were detected in the samples from this region. In the coastal samples, Aspergillus sp. were isolated from all samples, while the potentially aflatoxigenic A. Flavi contaminated about 80% of them. Aflatoxins were present in 50% of these samples, in ranges from 0.42 to 107.69 µg/kg. PCA was able to segregate the samples according to their collection region, and showed that the maximum and minimum temperatures are closely and positively related to the presence of A. Flavi. A highly positive relationship was also observed between the water activity of the sample and aflatoxin contamination. On the other hand, the altitude had a very strong—but negative—relationship with the variables studied. This study is relevant because data regarding fungi and aflatoxin occurrence, as well the main factor influencing the contamination of Ecuadoran maize, are scarce; it clearly shows that aflatoxins are a hazard present in maize from the Ecuadorian Coast but not the Highlands.

Control charts for health surveillance based on residuals of negative binomial regression

AbstractThis research presents control charts based on one‐sided exponentially weighted moving average (EWMA) control charts of Pearson, studentized Pearson, Deviance, and Studentized Deviance residuals for a negative binomial regression in order to detect increases in count quality variables used in health surveillance. Data of weekly dengue cases for the year 2018 from the coast of Ecuador were used for the design of control charts in phase I because in that year the weather conditions were normal, while dengue cases in 2019 were used for phase II of control. The control charts detected an increase in the weekly cases of dengue during 2019, a year in which the phenomenon of the Niño was present. In this study by simulations, it is shown that the smallest lambda values have a faster speed in detecting changes. If the objective is greater sensitivity, using studentized residuals is better, but if we seek simplicity and interpretation, Pearson residuals can be used.

Ground motion simulations in Quito (Ecuador) due to major earthquakes from the subduction zone

SUMMARY In 1906, an earthquake with a magnitude estimated between Mw 8.4 and 8.8 occurred in the subduction zone along the coast of Ecuador and Colombia. This earthquake caused extensive damage on the coast but had a rather small impact on the capital city of Quito, situated 180 km away. At that time, the city of Quito extended over a small area with a few thousand inhabitants, while today it stretches over 40 km and has a population of over 3 million, with most of the city built without paraseismic regulations. The aim of this study is to obtain new insights on the impact that large earthquakes from the subduction zone would have on the city today. This question is crucial since we know that the city of Quito is prone to site effects and that the southern part of the city amplifies seismic waves at low frequencies, around 0.3–0.4 Hz. In April 2016, an Mw 7.8 earthquake occurred on the subduction interface in the Pedernales area. This event was the first large earthquake in the city of Quito to be well recorded by 13 stations of the permanent accelerometric network (RENAC). In this study, we take advantage of this data set (main shock and large aftershock recordings) to (1) test an empirical Green's function blind simulation approach where the input stress drop is taken from a global catalogue of source time functions, (2) compare the synthetic accelerograms and ground motion values we obtain for an Mw 7.8 earthquake with the actual recordings of the Pedernales earthquake and then (3) simulate larger earthquakes of Mw 8.2 and 8.5 from the subduction zone. For Mw 7.8 simulations, our approach allows a good reproduction of the ground motions in the whole frequency bands and properly takes into account site effects. For Mw 8.2 and 8.5 simulations, we obtain for the stations in the southern part of the basin, larger values at low frequencies than the predicted motion given by ground motion models. These values, although high, should be supported by new or recent buildings if they are constructed respecting the building code that applies in Quito. Therefore, for this type of strong but distant earthquake, the seismic standards appear to be well suited and it is imperative to ensure that they are well considered in the design of the new buildings to be constructed, especially in the southern part of the expanding city.

Prices, specialty varieties, and postharvest practices: Insights from cacao value chains in Ecuador

AbstractEfforts to improve cacao value chains often assume that production of fine and flavor varieties will raise smallholder incomes. Undertaking postharvest practices of fermentation and drying is another exercise assumed to increase value‐added capture by smallholder producers. This study employs household data from 340 cacao farms in 15 villages in coastal Ecuador during 2018 to empirically assess these assumptions. Contrary to the common belief of the international development community, we find that the production of fine and flavor cacao varieties has no association with the price received by small‐scale producers. This is mainly due to (i) low productivity and (ii) nonexistent price premiums. Findings also suggest that the use of postharvest practices of fermentation and drying may lead to substantial price responses irrespective of the type of variety grown. The results presented here have implications for program interventions aimed at increasing farmer revenue. Programs promoting the use of fine and flavor varieties alone might be misguided and can be improved by training in modern processing techniques, regardless of the variety produced. [EconLit Citations: O12, Q01, Q12, Q13].

Geochemical characterization of crude oils and potential source rocks from southern coastal Ecuador: Hypothetical petroleum systems

This research paper encompasses an organic geochemical investigation on oils and sedimentary rocks from the southern coastal region of Ecuador that examines the hydrocarbon generation and accumulation in the strata of Progreso Basin Province. This petroliferous province represents an interesting area for an oil geochemistry study due to its non-elucidated petroleum systems. The present work focuses on the analysis of eighty-five oils and forty rock samples to determine kerogen types, depositional paleoenvironments, levels of thermal maturity, and in-reservoir petroleum biodegradation stages as well as to assess correlations between source facies and oil samples. Potential source rocks were selected and analysed from different outcrops and wells throughout the basin and the southern Gulf of Guayaquil. Classic biomarker, extended diamondoid, and isotope studies indicated that almost all oils from the Progreso Basin Province underwent biodegradation and were generated from multiple Tertiary source rocks deposited in a marine setting with significant influx of terrestrial organic material. Three families of oils were identified. Oil-source rock correlations suggest that the Socorro, Dos Bocas and San Eduardo formations can be considered as contributors to the studied oils. Geochemical data and previous thermal models point towards two probable hydrocarbon kitchens defined in the deepest parts of the basin as well as a third possible kitchen extended offshore beyond the Santa Elena Peninsula.

Demographics and dynamics of the world’s largest known population of oceanic manta rays Mobula birostris in coastal Ecuador

Information on the life history and demographics of oceanic manta raysMobula birostrisremains scarce. Using photo-ID data, we describe the demographic structure, population size, and possible environmental drivers of the seasonal occurrence ofM. birostrisat Isla de la Plata and Bajo Copé, Ecuador. We identified a total of 2803 individuals from 3322 encounters over a period of 14 yr (2005-2018). The population sampled at these sites was significantly biased towards males (sex ratio 1F:1.67M) and only 12.9% of individuals were resighted. We used mark-resight models to estimate demographic parameters of the population, including superpopulation size, survival probability, entry/recruitment probability, and detection probability. We also evaluated how these parameters were related to environmental predictors, such as El Niño-Southern Oscillation (ENSO), sea surface temperature (SST), and chlorophylla(chla). Mark-resight analyses indicated that SST, chla, time, and sex, but not ENSO, were important predictors of estimated population parameters. Entry probability peaked in 2012, which coincided with the lowest SST and highest chlaconcentrations. The best-fit mark-resight model estimated a superpopulation size of 22316 individuals, with annual estimated abundances of 949-7650 females and 5226-9340 males. Localised sampling of this highly mobile species limits the interpretations of mark-resight analyses, but provides lower bounds for total abundance that indicate the population ofM. birostrisin coastal Ecuador and Peru is likely the largest in the world.

Six forests in one: Tree species diversity in the Bosque Protector Chongón Colonche, a lowland mountain range in coastal Ecuadorian

Tropical mountain ranges shape the structure of tree communities and promote highly diverse natural habitats. The “Bosque Protector Chongón-Colonche” (BPCC), an 86,000-ha mountain formation situated on the coast of Ecuador, is biogeographically important for the region by connecting floristic elements of the wet Choco and the dry Tumbesian forests. Our understanding of the factors that model tree and palm diversity and distribution in this mountain range are limited. We measured and identified all trees and palms (DBH ≥10 cm) in 289 plots of 0.2 ha, distributed throughout BPCC. We used generalized linear models to explain the relationship between forest diversity and structure and climatic variables (temperature, rain, aridity), and altitude. We then used cluster and non-metric multidimensional scale (NMDS) analyses to search for distinct forest communities within the BPCC. Variance partition (varpart) was used to determine which predictor variables best explained these distinct forest communities. A species indicator analysis identified the species most likely to define these distinct forest communities. Finally, we carried out a niche modeling approach to identify the potential distribution of these forest communities within BPCC. In total, we identified 220 tree and palm species in our survey. The average number of species per plot was 17.8 ± 5.8, ranging from 3 to 40 species. Classification methods sorted the 289 study plots into six different forest communities, three communities in the dry forest and three in the semi-humid Garúa forest. Precipitation and temperature, but not altitude or aridity, explained floristic composition. These results emphasize the high but little cataloged diversity in the lowland mountain rainforests of coastal Ecuador.

Hydroterritorial Configuration and Confrontation: The Daule-Peripa Multipurpose Hydraulic Scheme in Coastal Ecuador

There is a forceful new impetus toward mega-hydraulic projects in Latin America, which are booming but also highly controversial. They bring benefits to some social groups while many others are negatively affected. Technocratic discourses are dominant in the region; they strategically mobilize institutions, infrastructure, money, and knowledge to present particular hydrosocial territorial imaginaries—such as multipurpose dams—as natural, universal, and politically neutral. Meanwhile, affected local communities commonly envision and practice different discourses, values, and worldviews, based on contextualized notions of well-being and territoriality. Using a political ecology perspective, this article examines how the Daule-Peripa mega-hydraulic scheme—Ecuador’s “hydraulic heart”—has de- and repatterned the territory, producing new hierarchical relations and unequal distribution of socioenvironmental impacts. Though political discourses have changed throughout state-centralist and neoliberal époques, governmental policies and practices have continued and renewed their defense of mega-hydraulism. In turn, affected communities and families, through everyday territorial politics, respond and aim to rearrange the hydrosocial network in order to regain control over water, land, and territorial services.

Touristification, urban renovation and political ecology: contestation in three citites on the coast of Ecuador

La llegada del turismo internacional ha impulsado en las diferentes ciudades del Ecuador nuevos planes y políticas públicas de renovación para adaptarse a este modelo. De esta forma, han surgido nuevos espacios de calidad ambiental dentro de la ciudad: espacios de playa para el ocio, de manglar para el paseo o nuevos parques como forma de revalorización. La “renovación” de áreas para la llegada de turistas en zonas antes consideradas como espacios no urbanizables, ocupadas por las clases populares, produce un desplazamiento forzoso con distintos grados de violencia. Para mitigar las contradicciones sociales de esta violencia, los responsables de la toma de decisiones habilitan espacios de vivienda de interés social fuera de los límites de la ciudad, en espacios naturales, generando una pérdida de centralidad y de acceso a la ciudad para la población desplazada. La renovación urbana de Esmeraldas, Portoviejo y Guayaquil ecologiza las políticas de las áreas centrales y profundiza una periurbanización devastadora mediante la construcción de complejos de vivienda social, reordenando la espacialización de las clases sociales en la ciudad.

Small non-volant mammals from Bosque Protector Cerro Blanco, a fragment of tropical dry forest in western Ecuador

Basic diversity studies of small non-volant mammals are scarce in western Ecuador, evidencing a knowledge gap regarding the mammalian fauna in the region. These organisms play key roles in important ecological processes and may be affected by several anthropogenic factors. Herein we report the results of a rapid assessment of marsupials and rodents of Bosque Protector Cerro Blanco (Guayas province), a fragment of dry forest surrounded by urban development. Between October 2016 and March 2017, we trapped rodents and marsupials with Sherman and Tomahawk live traps; also, we conducted direct observations and searched for skeletal remains. We recorded nine species of small non-volant mammals, seven native and two invasive. The marsupial Marmosa simonsi was the most frequently captured species. We reported three previously unrecorded species for this reserve: Sigmodon peruanus, Aegialomys baroni, and Rhipidomys latimanus. We recommend continued monitoring of the mammalian fauna of Cerro Blanco using alternative techniques such as pitfall traps, canopy live traps, and analysis of owl pellets. These efforts will permit a better understanding of the marsupial and rodent assemblage in this important site for biodiversity conservation in coastal Ecuador, a region that unfortunately faces intense human pressure.

Biodiversidad de ecotipos y rangos de agresividad de Moniliophthora perniciosa, en Theobroma cacao L. nacional del Litoral Ecuatoriano

The objective of the work was focused on studying the biodiversity of ecotypes and aggressiveness ranges of Moniliophthora perniciosa, in Theobroma cacao. Plant material with the presence of the pathogen from 12 plantations of T. cacao L Nacional was sampled, analyzing its morphological characteristics, identification by PCR and the aggressiveness of the disease in national cacao EET-19. The basidiocarps differ in size and basidiospore production considering the strain MpLRBF-105 with the largest diameter of basidiocarp and basidiospore discharge. The basidiocarps differ in size and basidiospore production considering the strain MpLRBF-105 with the largest diameter of basidiocarp and basidiospore discharge. The content of lamelulas would be adding the increase of basidiospores in the strains (MpLRBF105 and MpBOLN107), with the largest dimensions between lengths of (11.58 to 12.01 µm) and width (6.23 and 5.95 µm) in the strains (MpLRBA-101, MpLRVE-102, MpLRMO-103, MpGUBA-104, MpLRBF-105 and MpBOLN-107). The genetic characterization of the ITS region of M. perniciosa showed genetic variability with the formation of three Sub-groups, this corresponds to their different agroecological zones of the Ecuadorian Coast. The highest degree of aggressiveness due to M. perniciosa infection gave rise to cotyledonal brooms with (4 to 11 axillary brooms) for the MpLRBF-105, MpGUBA-104, MpLRMO-103, and MpLRVE-102 strains. With 68% inhibition in fresh root weight, strain MpGUBA-104 (Balao). Consequently, the climatic conditions and the pressure to increase commercial plantations of T. cacao CCN-51, are generating changes in the ecology of M. pernciosa.

Метод гауссова обучения нейронной сети для решения задачи распознавания многоспектральных спутниковых изображений

The methods of Gaussian computer vision and machine learning used to process multispectral satellite images in the detection and recognition of research objects --- banana plantations in the area of El Porvenir on the coast of Ecuador --- are considered. Using computer vision and machine learning techniques, processing of multispectral satellite images and indirect raster data after calculating NDVI and NDWI vegetation indices, classification of vegetation and water objects was performed. The analysis of multispectral satellite image data is complicated by the presence of clouds and rasters that do not contain data other than the object of study. The machine learning method when labeling data with validation by vegetation indices is used in segmentation of classes that do not participate in the computer vision analysis in the detection and recognition of the research object. The probability of the given positive experimental results is ~ 96 %. The proposed methods of objects detection and recognition on multispectral satellite images can be implemented in agricultural systems to improve, analyze and assess the needs of crops, which are part of agriculture as the primary sector of the economy, to meet the needs of food and raw materials production. Thus, with the increased demand for agricultural products, it is necessary to introduce technologies that guarantee the quality and high productivity of agricultural machinery

Standing Water and Missing Data: The Murky Relationship between Flooding and Mosquito-Borne Diseases.

Standing Water and Missing Data: The Murky Relationship between Flooding and Mosquito-Borne Diseases.

Exploring Dental Modification from Coastal Ecuador from an Unprovenienced Museum Collection

In South America, most examples of dental modification come from Ecuador; however, none have been directly radiocarbon dated and few have associated cultural materials or context. In fact, many modified teeth and crania are housed in museum collections, divorced from their cultural and temporal milieus, and because of this it is generally assumed that this limits the interpretive possibility of these individuals. We used multiple methods to investigate temporal and geographic origins of seven crania with dental modification housed in the Museo Antropológico y Arte Contemporáneo in Guayaquil, Ecuador. We identified diverse forms of dental modification, including dental inlays and appliques, incised lines, and anterior dental avulsion. Additionally, teeth from four modified individuals were sampled for radiocarbon dating and isotopic analyses (Sr, Pb, O). The dates indicate that dental modification persisted for at least 600 years (cal. A.D. 990–1646). The relatively heavy oxygen isotopes in the sampled teeth are consistent with Ecuador as a place of origin for the four individuals assayed, but strontium isotopes are quite varied, from 0.70462 to 0.70777 indicating that they did not reside in the same geographical area. Interestingly, the observed variations in strontium isotopes in the four individuals are lower than the modeled 87Sr/86Sr for the region. The values suggest the individuals resided in terrains with volcanic bedrock, which are abundant in Ecuador, yet their influence on the strontium isoscapes is not well represented by the published regional models. This analysis highlights the utility of multiple methods in bioarchaeology and biogeochemistry to investigate “orphaned” museum collections.&#x0D; &#x0D; En Sudamérica, la mayor parte de los ejemplos de modificación dental surgen de Ecuador; sin embargo, ninguno de estos casos ha sido fechados utilizando análisis de radiocarbono y pocos están asociados con contextos o materiales culturales. De hecho, varios dientes y cráneos modificados están localizados en colecciones museísticas y han sido divorciados de sus entornos culturales y temporales originales, generalmente con la suposición que limitan la posibilidad interpretativa de estos individuos. Nosotros utilizamos varios métodos bioarqueológicos y biogeoquímicos para investigar los orígenes temporales y geográficos de siete cráneos con modificaciones dentales ubicados en el Museo Antropológico y Arte Contemporáneo en Guayaquil, Ecuador. Nosotros identificamos varias formas de modificaciones dentales, incluyendo incrustaciones y aplicaciones dentales, incisiones de líneas y avulsión dental anterior. Adicionalmente, los dientes modificados de cuatro individuos fueron muestreados para fechar con análisis de radiocarbono y análisis isotópico (Sr, Pb, O). Las fechas indican que la modificación dental persistió durante por lo menos 600 años (990–1646 DC). Los isótopos de oxígeno relativamente pesados en los dientes muestreados son consistentes con Ecuador como lugar de origen para los cuatro individuos analizados, pero los isótopos de estroncio son bastante variados, de 0.70462 a 0.70777, lo que indica que no residían en la misma área geográfica. Las variaciones observadas en los isotopos de estroncio son más bajes de los 87Sr/86Sr modeladas para la región e indican que estos individuaos residían en regiones con la roca de fondo volcánica. Las rocas volcánicas son abundadas en Ecuador y aparentemente no está bien representadas en los modelos. Aún más, esta es la primera evidencia bioarqueológica sugerente de avulsión dental en Ecuador prehispánico. Finalmente, este análisis resalta la utilidad de métodos mixtos en bioarqueología y biogeoquímica para investigar colecciones museísticas que han “quedado huérfanas”.

Seasonal-To-Interannual Variability of Sea-Surface Temperatures in The Inter-Americas Seas: Pattern-Dependent Biases in The Regional Ocean Modeling System

The Inter-Americas Seas (IAS), involving the Gulf of Mexico, the Caribbean and a section of the eastern tropical Pacific Ocean bordering Central America, Colombia and Ecuador, exhibits very active ocean-land-atmosphere interactions that impact socio-economic activities within and beyond the region, and that are still not well understood or represented in state-of-the-art models. On seasonal-to-interannual timescales, the main source of variability of this geographical area is related to interactions between the Pacific and the Atlantic oceans, involving to anomalous sea-surface temperature (SST) patterns like El Niño-Southern Oscillation (ENSO), and regional features in the Caribbean linked to the bi-modal seasonality of the Caribbean Low-Level Jet. This study investigates seasonal-to-interannual IAS surface-temperature anomalies in observations, and their representation in am eddy-permitting, 1/9o-resolution simulation using the Regional Ocean Modeling System (ROMS), interannually-forced by the Climate Forecast System Reanalysis. Here, rather than analyzing model biases locally (i.e., gridbox-by-gridbox), a non-local SST pattern-based diagnostic was conducted via a principal component analysis. The approach allowed to identify magnitude, variance and spatial systematic errors in SST patterns related to the Western Hemisphere Warm Pool, ENSO, the Inter-American Seas Dipole, and several other variability modes. These biases are mainly related to errors in surface heat fluxes, misrepresentation of air-sea interactions impacting surface latent cooling in the Caribbean, and too strong sub-surface thermal stratification, mostly off the coast of Ecuador and northern Peru.