Coastal Ecuador Research Articles

Passiflora guayaquilensis (Passifloraceae): a new species of wild passion fruit from coastal Ecuador

Passiflora guayaquilensis (Passifloraceae), a new species of wild passion fruit in subg. Decaloba from the seasonally deciduous dry forests of coastal Ecuador is here formally described and illustrated. The new species is similar to Passiflora morifolia, but differs notably in the morphology of the flower and fruit. The conservation status of P. guayaquilensis is assigned here as Vulnerable.

Diversity in the invasive cacao pathogen Moniliophthora roreri is shaped by agriculture

AbstractFrosty pod rot disease of cacao (FPR), caused by the fungus Moniliophthora roreri, has severely impacted the production of cocoa in Latin America since its discovery. Prior to the 1950s, FPR was known only from Colombia and Ecuador. However, beginning in the 1970s, its geographical range has dramatically expanded throughout most of the cacao‐producing regions of the Americas. The origin of the pathogen remains unknown. In this study, we evaluated the genetic diversity of M. roreri from areas spanning, as much as possible, its current geographical range using simple‐sequence repeat markers and a publicly available single‐nucleotide polymorphism data set. Two hotspots of genetic diversity were found: coastal Ecuador and the inter‐Andean Magdalena Valley of Colombia, neither of which correspond to the Amazonian origin of the host. However, both areas were early centres of intense cultivation of cacao. Our results indicate that M. roreri was introduced into both areas from its centre of origin, where intensive cacao cultivation probably led to the increase of inoculum and further dissemination of the disease. Current invasions can be traced to two genotypes responsible for all known instances of the pathogen in Central America, the Caribbean, Peru and Bolivia. We also report for the first time M. roreri in Maynas (Peruvian Amazon), which is probably the result of a recent introduction from Colombia.

The importance of community during rapid development: The influence of social networks on acute gastrointestinal illness in rural Ecuador

Social networks are often measured as conduits of infection. Our prior cross-sectional analyses found that denser social ties among individuals reduces transmission of acute gastrointestinal illness (AGI) in coastal Ecuador; social networks can describe both risk and protection. We extend findings to examine how social connectedness influences AGI longitudinally in Ecuador from 2007 to 2013, a time of rapid development, using a two-stage Bayesian hierarchical model to estimate multiple network effects. A larger community network of people to discuss important matters with was consistently protective against AGI over time, and a network defined by people passing time together became a stronger measure of risk, due to increasing population density and travel. These networks were interdependent: the joint effect of having a small passing time network and large important matters network reduced the odds of AGI over time (2007: OR 1.16 (95% CI: 0.94, 1.44), 2013: OR 0.56 (95% CI: 0.45, 0.71)); and synergistic: the people an individual passed time with became the people they discussed important matters with. Focus groups emphasized that with greater remoteness came greater community cohesion resulting in safer WASH practices. Social networks can enhance and reduce health differently as social infrastructure evolves, highlighting the importance of community-level factors in a period of rapid development.

Obsidian acquisition networks in northern Ecuador from 1600 to 750 cal BCE

Since a pair of seminal studies in the mid-1990́s, obsidian provenience research in Ecuador has shown limited advancement with regard to analysis of archaeological materials. Investigations of the relevant sources have been the primary focus. While these are important, especially given the complex nature of the major Ecuadorian sources, more investigation is required to analyze how prehispanic populations acquired this material that frequently is used as a proxy for interregional interaction. This article advances our understanding on this front by presenting the portable X-Ray Fluorescence (pXRF) analysis of 401 artifacts from five sites in northern Ecuador with absolute dates spanning from 1600 to 750 cal BCE. The results permit a finer-grained reconstruction of procurement patterns than the typical relative period approach. Three principal findings are proposed: the utilization of Yanaurco-Quiscatola obsidian declined during the period of interest, the Mullumica source became the center of obsidian procurement as the utilization of these other sources fell, and two interregional networks existed that resulted in populations on the northern Ecuadorian coast acquiring obsidian.

Persistent companionships: The parasitic copepod community of the dolphinfishCoryphaena hippuruson the Ecuadorian coast

The common dolphinfish, Coryphaena hippurus, is an important and widespread fishing resource in tropical and subtropical latitudes. It harbors a diverse array of parasitic copepods, but data on their infection indices are quite limited worldwide. We analyzed its parasitic copepod community and infection indices based on the examination of 615 individuals of C. hippurus landed monthly on the coast of Ecuador, over a period of 1 year. Both the opercular cavities and gills of the sampled fish were examined for parasitic copepods, of which nine taxa were recorded: Brachiella quaternia, Caligus belones, C. bonito, C. coryphaenae, C. productus, Euryphorus brachypterus, E. nordmannii, Lepeophtheirus sp., and Lernaeenicus sp. The finding of five of these species (i.e., B. quaternia, C. belones, C. productus, E. brachypterus, and E. nordmannii) represents new geographic records. C. bonito showed the highest prevalence (83%), mean abundance (5.46 ± 4.99), and mean intensity (6.57 ± 4.99), followed by B. quaternia (prevalence = 32%, mean abundance = 1.89 ± 5.66, mean intensity = 5.89 ± 5.71). The infection indices of C. bonito decreased with increasing host length and were higher in females than in males. The parasitic copepod community of common dolphinfish in this study was similar to communities in other parts of its geographic distributional range, including the Atlantic Ocean, the Mediterranean Sea, and the Eastern Pacific, consistently dominated by a generalist parasitic species. This is the first and most detailed quantitative evaluation of the parasitic copepods associated with the dolphinfish and updates the extant parasitological data for this host.

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.