Tobes, Ibon
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Tobes, Ibon
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Quito
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ibontobes@uti.edu.ec
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54950128400

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Microplastics in Two Tropical Andean Lakes: Contrasting Human-Impacted and Minimally Disturbed Watersheds

2026 , Andrés Arévalo-Moreno , Silvana Gallegos-Sánchez , Kevin Valencia , Tobes, Ibon

Microplastics (MPs) are emerging contaminants in freshwater systems, yet their sources and transport pathways in tropical high-altitude lakes remain poorly understood. This study quantified and characterized MPs in two Andean lakes in Ecuador with contrasting watershed conditions: San Pablo (2672 m a.s.l.), influenced by agricultural and urban land use, and Caricocha (3724 m a.s.l.), a protected high-Andean lake. Sixteen samples per lake were collected during four field campaigns. MPs were identified using visual and morphological criteria, and classified by shape, color, and size. MP concentrations were higher in San Pablo (238 ± 32 MP m−3, mean ± SD) than in Caricocha (32 ± 10 MP m−3). Fibers dominated (87.3%), followed by fragments, while microspheres were detected only in Caricocha. MP concentrations showed positive correlations with urban-agricultural land use (ρ = 0.87, p < 0.0001) and negative correlations with natural vegetation cover (ρ = −0.87, p < 0.0001). Principal Component Analysis linked fiber abundance and small size classes (<500 µm) and anthropogenic land use, consistent with surface runoff and wastewater-associated pathways. In contrast, MPs in the protected lake may originate from long-range atmospheric deposition. These results indicate that watershed configuration and protection status shape MP inputs in high-Andean lakes.

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Water quality assessment of the cutuchi river basin (Ecuador): A review of technical documents

2021 , Zapata D. , Oleas Gallo, Nora Helena , Páez-Vacas, Mónica , Tobes, Ibon

The Cutuchi River Basin extends over the inter-Andean valley south of the Cotopaxi Volcano, in Ecuador. It flows through two provinces, Cotopaxi and Tungurahua, and its waters are extensively used to irrigate crops that provide food to the main cities in the country. Unfortunately, the basin receives untreated domestic and industrial discharges. The need for an environmental quality assessment of the river has been acknowledged over the years. The aim of this study is to gather information about water quality of the Cutuchi River through a historical bibliographic review. A total of 57 works published between 2007 and 2018 were found, including books, articles, thesis and project reports. Only 18 documents provided biological, physical, or chemical data linked to water quality. The data obtained through the literature review were compared with maximum thresholds from national and international regulations. Unfortunately, revised studies were scattered on time and randomly along the basin and did not provide robust information to evaluate the state of the water-system. Some contamination was detected significantly exceeding safety thresholds. More exhaustive studies along the basin are needed as a baseline to help the decision makers to design management plans and mitigate human impacts. © 2020 Institute of Physics Publishing. All rights reserved.

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A new species of microglanis (Siluriformes: Pseudopimelodidae) from the pacific slope of Ecuador [Se describe una nueva especie de bagre para la cuenca del río esmeraldas, vertiente del pacífico, en el norte de Ecuador]

2020 , Tobes, Ibon , Falconí-López A. , Valdiviezo-Rivera J. , Provenzano-Rizzi F.

A new species of catfish is described from the Esmeraldas River Basin, Pacific slope, northern Ecuador. Tentatively included in Microglanis, represents the second species of the genus inhabiting the Trans-Andean region. The new species is distinguished from known congeners by a unique combination of external characteristics: head and body color pattern, uniform, pale brown, yellowish or grayish, without any kind of blotches, bands or dots, only a lunate transverse band, dark or black, at caudal-fin origin; adipose-fin origin and forward without lighter or luminous areas. Compared with M. variegatus, the new species has morphometric differences, such as the distances between dorsal and pelvic fins, and between posterior nostrils. Some osteological characteristics are compared with those observed in species of Pseudopimelodidae inhabiting the Pacific versant of Colombia and Ecuador and with some other species of Microglanis. © 2020 The Authors.

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Fish Ecology and Hydrological Responses to a Run-of-River Hydroelectric Project in Ecuador

2025 , Tobes, Ibon , Emily Conrad , Jordi Rivera-Albuja , Blanca Ríos-Touma , Rafael Miranda

Hydropower development is rapidly expanding in biodiversity-rich regions like the Ecuadorian Andes, raising major concerns about its ecological impacts. This study evaluates fish species composition and habitat characteristics in the Cristal and Dulcepamba Rivers, with a particular focus on the effects of the San José del Tambo Hydroelectric Project on the Dulcepamba River. Sampling conducted during the dry season (November–December 2023) at 15 sites incorporated fish surveys, habitat analyses, and environmental quality evaluation. The results showed marked declines in fish abundance, richness, and diversity in sections of the Dulcepamba River directly affected by water diversions, with species richness reduced to only three species at a site most impacted by discharge reduction. Conversely, the Cristal River, with its unaltered hydrology, supported considerably greater diversity, including 12 species at one site. Environmental integrity indices (Andean–Amazon Biotic Index, Biological Monitoring Working Party Index, Andean Riparian Quality Index, and Fluvial Habitat Index) further underscored the Cristal River’s superior conservation status. In the Dulcepamba River, reduced discharge in the environmental flow of the Hydroelectric Project—below mandated environmental discharge levels—led to river drying, disrupted connectivity, and impaired fish migration. This study provides essential insights into these highly biodiverse yet poorly studied ecosystems, which are increasingly threatened by anthropogenic pressures. The findings highlight the critical need to reconcile energy development with conservation efforts in these vulnerable Andean environments.

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Diagnosing stream ecosystem integrity in the Ordesa-Viñamala Biosphere Reserve, central Spanish Pyrenees

2016 , Tobes, Ibon , Gaspar S. , Oscoz J. , Miranda R.

This work studied the ecological integrity of river ecosystems inside the Ordesa-Viñamala Biosphere Reserve in the central Spanish Pyrenees. Despite its protected status, the reserve endures a considerable number of human stresses, thus the aim was to evaluate the conservation status of the two river basins inside the protected area: The Gállego River Basin, inside the transition zone of the protected area and which allows a wide range of human activities; and the Ara River Basin, inside the buffer zone where only sound ecological practices are authorised. The environmental status of river ecosystems was analysed by studying fish and macroinvertebrate communities, hydrochemical and habitat characteristics and by calculating environmental quality indices. From August to September 2011, a total of 14 sites were sampled. Fish sampling was conducted using electrofishing gear, and macroinvertebrate were sampled by applying the IBMWP and IASPT procedures. Results showed that, while the Ara River Basin maintains a solid ecological integrity, the Gállego River Basin endures important habitat alteration. Trout, the dominant and exclusive species in the Ara River, were absent and replaced by translocated native cyprinids in the Gállego River Basin. This colonisation was explained by the alteration of the stream ecosystems and their homogenisation. The study of macroinvertebrate communities and the diagnosis obtained with the environmental quality indices also enhanced the deficient ecological integrity of some sites in the Gállego River. The results suggest that the Biosphere Reserve is not providing adequate protection to streams inside its boundaries, leading to major degradation of their biological integrity. © 2016 Blackwell Verlag GmbH

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NEOTROPICAL FRESHWATER FISHES: A dataset of occurrence and abundance of freshwater fishes in the Neotropics

2023 , Tobes, Ibon

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications. © 2022 The Ecological Society of America.

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Environmental Patterns of Phytoplankton Community Composition Across Lentic and Lotic Systems in Ecuador

2026 , Andrés Arévalo-Moreno , Mabel Cadena , Kevin Valencia , Tobes, Ibon

Phytoplankton are key indicators of water quality and low-cost tools for freshwater monitoring, yet their diversity and ecological drivers remain poorly documented in the Tropical Andes. This study provides the first national-scale, multi-ecosystem assessment of net phytoplanktonic communities (including microalgae and cyanobacteria), across Ecuador, integrating physicochemical, multivariate, and geospatial analyses. Eighteen lakes and rivers from three biogeographic regions and a wide altitudinal gradient were surveyed, yielding 129 taxa, 77 identified at species level, the most comprehensive checklist reported to date for Ecuador. Community structure showed a clear lentic–lotic differentiation driven by hydrodynamic contrasts, while the absence of distance–decay patterns indicated high dispersal and environmental filtering pattern rather than spatial structuring. Anthropogenic pressure acted as a secondary gradient: pristine high-Andean lakes were dominated by desmids and diatoms, whereas agricultural and urban basins showed chlorophyte and potentially toxic cyanobacterial assemblages. Palmer’s Index detected organic pollution but underestimated eutrophication in endorheic, geochemically enriched lakes. Land-use effects presented strong basin-scale signals in lakes but weak correlations in rivers due to overriding hydromorphological constraints. These findings establish a robust spatial baseline for freshwater bioassessment in the Andes, demonstrating the value of phytoplankton as effective, low-cost indicators readily applicable to national water-quality assessment programs.

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Evaluating the influence of environmental variables on fish assemblages along Tropical Andes: considerations from ecology to conservation

2022 , Miranda, R. , Rios-Touma, B. , Falconí-López, A. , Pino-del-Carpio, A. , Gaspar, S. , Ortega, H. , Peláez-Rodríguez, M. , Araujo-Flores, J.M. , Tobes, Ibon

The lack of knowledge about freshwater biodiversity in remote areas like montane Andean rivers is noticeable and hinder the development of efficient conservation plans for aquatic ecosystems. Habitat requirements of tropical Andean fishes have been poorly analysed, despite the relevance of these ecological features on the fish conservation strategies. The present study aimed to examine fish assemblages along the altitudinal gradient in tropical Andean rivers and their relationship to habitat features to detect the most relevant abiotic factors and their implication on conservation. This study was conducted on a regional scale, along six basins located in tropical Andes (500 to 2,692 m a.s.l.). We studied fish diversity and distribution and their habitats along these elevation gradients. We found 6,320 specimens from 53 genera. Our analysis for the six most common and widely distributed genera (Astroblepus, Brycon, Bryconamericus, Chaetostoma, Pimelodella and Trichomycterus) underlines the relevance of hydromorphological variables on fish community structure in the Andean montane rivers, whereas human alterations seem to be less significant. These findings could be useful for current management and conservation strategies considering present threats over tropical montane rivers. © 2021, The Author(s).

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Upcycling the Banana Industry in Ecuador: A Methodology to Estimate Biowaste and Catalogue of Bioproducts

2023 , Jiménez M.P.S. , Tobes, Ibon

Ecuador is the leading exporter of bananas globally. This industry generates a large amount of organic waste since the plant is cut down for every crop, but only the fruit bunch is used. These residues can be converted into sustainable environmental products that could replace polluting materials. This investigation presents a GIS-based methodology used to estimate the biomass of the residues of banana agriculture in Ecuador and to determine how much organic waste could be used as raw materials to manufacture new biodegradable products. We estimated that more than forty million metric tons of waste are produced every nine months. Our methodology can be a low-cost quantitative complement to the survey-based estimations conducted by the Ecuadorian government to evaluate banana production. Additionally, our work presents five products that could be manufactured with organic waste, like disposable plates, bioplastics for food utensils, cardboard covers, fibers for hydraulic cement, and wallpaper. Finally, we offer a product catalog developed as a technical guide for future bio-enterprises to elaborate biodegradable products inspired by a circular economy scheme. In light of the estimated amount of banana waste generated in the country, we consider that Ecuador has the potential to develop an industry based on this raw material to generate products such as those proposed in our review, shifting the banana industry to a more sustainable, profitable process, and generating new incomes and sources of employment. © 2023,. All Rights Reserved.

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Hydrocarbon tolerance evaluation of the microbiota associated with the Roystonea oleracea palm from Santay Island (Ecuador)

2024 , Andrade, Jean Carlo , Santiago Mafla , Kelly Riofrío , José Hernández , Tobes, Ibon , Cristian Lara-Basantes

Soil contamination from hydrocarbon spills has resulted in significant environmental repercussions on a global scale. Bioremediation, which involves the use of living organisms such as microbes to remove contaminants from polluted ecosystems, offers a promising solution. In this study, tolerance tests on hydrocarbons present in Jet Fuel A1 were carried out, utilizing microorganisms isolated from four soil samples (M1, M2, M3, and M4) collected at varying distances from the rhizosphere of Roystonea oleracea on Santay Island, a RAMSAR wetland located in the Guayas River estuary on the Pacific coast of Ecuador. Sample M1 was closest to the base of the palm, while M4 was the farthest. Various soil ions, including potassium, phosphates, iron, and total nitrogen, were analyzed, and higher concentrations were found near the base of the palm. Additionally, a metabolic profile analysis of the samples was conducted using Ecoplate® kits, which revealed similar trends, with carbon sources being predominantly consumed near the base. A community-level analysis was performed using Denaturing Gradient Gel Electrophoresis (DGGE), followed by molecular characterization through amplification of the 16S RNA conserved region via the Sanger method. The identified microorganisms included Lysinibacillus fusiformis, Lysinibacillus boronitolerans, Alcaligenes faecalis, and Bacillus soli in the soil samples. Notably, strains isolated from samples near the palm's base were able to grow in media enriched with Jet Fuel A1 and demonstrated the ability to produce biosurfactants, as determined by the drop-collapsing method. The results obtained present opportunities for future research in the exploration of novel green remediation technologies.

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