Mauricio Valderrama

Bio: Mauricio Valderrama is an academic researcher. The author has contributed to research in topics: Drainage basin & Endemism. The author has an hindex of 1, co-authored 1 publications receiving 19 citations.

Ictiofauna y desarrollo del sector hidroeléctrico en la cuenca del río Magdalena-Cauca, Colombia

Abstract: The Magdalena-Cauca River basin has 213 species of freshwater fish, of which slightly more than 50% are endemic. This basin accounts for 80% of the Colombian population, holds 80% of the national GDP and within its channels are located the 84% of the hydroelectric plants that supply energy to Colombia. The Andean mountains generate altitudinal gradients in aquatic systems as well as its associated biota along the Magdalena-Cauca basin. To analyze the interaction between the altitudinal gradient in the distribution of species of freshwater fish and the location of existing reservoirs, it was performed an analysis of the altitudinal distribution of endemic and migratory fish species and their implications for their conservation based on the current and future state in the formation of reservoirs, using a review of case studies at global and national levels. It was found that the number of species is inversely proportional to altitude, while the endemics are directly proportional and reservoirs below 700 m altitude affect the conservation status of migratory species. A reservoir creates new species richness gradients and modifies the channels that are used by migratory species as spawning areas. We conclude that the development of the hydropower based on the use of water in the Andean rivers and another activities associated with economic development of Colombian society, has led to changes in freshwater aquatic systems in the Magdalena-Cauca basin, influences in the structure of the assemblages of species of fish and in the dynamic of migration and spawning of freshwater fish species important for artisanal fisheries.

Basin-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia

Abstract: A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompos Depression wetlands, one of the largest wetland systems in South America at 3400 km 2 Annual large-scale inundation of floodplains and their associated wetlands regulates water, nutrient, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies In this study, we implemented an integrated approach focused on key attributes of ecologically functional floodplains: (1) hydrologic connectivity between the river and the floodplain, and between upstream and downstream sections; (2) hydrologic variability patterns and their links to local and regional processes; and (3) the spatial scale required to sustain floodplain-associated processes and benefits, like migratory fish biodiversity The implemented framework provides an explicit quantification of the nonlinear or direct response relationship of those considerations with hydropower development The proposed framework was used to develop a comparative analysis of the potential effects of the hydropower expansion necessary to meet projected 2050 electricity requirements As part of this study, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the floodplains water balance at a medium scale ( ∼ 1000 to 10 000 km 2 ) and evaluation of the potential impacts of upstream water management practices In the case of the Mompos Depression wetlands, our results indicate that the potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 976 and 80 %, respectively, from pre-dam conditions In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry years and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompos Depression

Assessing conservation priorities of endemic freshwater fishes in the Tropical Andes region

Abstract: Marcelo F. Tognelli | Elizabeth P. Anderson | Luz F. Jiménez‐Segura | Junior Chuctaya | Luisa Chocano | Javier A. Maldonado‐Ocampo | Lina Mesa‐Salazar | José I. Mojica | Fernando M. Carvajal‐Vallejos | Vanessa Correa | Hernán Ortega | Juan F. Rivadeneira Romero | Paula Sánchez‐Duarte | Neil A. Cox | Max Hidalgo | Pedro Jiménez Prado | Carlos A. Lasso | Jaime Sarmiento | Miguel A. Velásquez | Francisco A. Villa‐Navarro

Ecological niche modeling as an effective tool to predict the distribution of freshwater organisms: The case of the Sabaleta Brycon henni (Eigenmann, 1913).

Abstract: Ecological niche models (ENMs) aim to recreate the relationships between species and the environments where they occur and allow us to identify unexplored areas in geography where these species might be present. These models have been successfully used in terrestrial organisms but their application in aquatic organisms is still scarce. Recent advances in the availability of species occurrences and environmental information particular to aquatic systems allow the evaluation of these models. This study aims to characterize the niche of the Sabaleta Brycon henni Eigenmann 1913, an endemic fish of the Colombian Andes, using ENMs to predict its geographical distribution across the Magdalena Basin. For this purpose, we used a set of environmental variables specific to freshwater systems in addition to the customary bioclimatic variables, and species' occurrence data to model its potential distribution using the Maximum Entropy algorithm (MaxEnt). We evaluate the relative importance between these two sets of variables, the model's performance, and its geographic overlap with the IUCN map. Both on-site (annual precipitation, minimum temperature of coldest month) and upstream variables (open waters, average minimum temperature of the coldest month and average precipitation seasonality) were included in the models with the highest predictive accuracy. With an area under the curve of 90%, 99% of the species occurrences and 68% of absences correctly predicted, our results support the good performance of ENMs to predict the potential distribution of the Sabaleta and the utility of this tool in conservation and decision-making at the national level.

Aquatic macroinvertebrates as water quality bioindicators in Colombia: A systematic review

Abstract: The use of aquatic macroinvertebrates to assess water quality has been growing during the last 50 years in Colombia. We conducted a systematic review of 109 references to analyze scientific production related to the evaluation of water quality in Colombian freshwater ecosystems, using aquatic macroinvertebrates. We describe bibliographical, geographical, ecological, and methodological characteristics of these studies. In the last two decades, there was an increase of more than 50% of publications. The Andean region was the most studied, while the other regions had few research. Lotic ecosystems were widely studied, unlike the lentic ones. The main land use management was agricultural. BMWP and diversity indices were the most used in the analyses. Further research is necessary in lentic ecosystems since they are being severely impacted by anthropogenic pressures, but were not assessed yet. Different regions that harbor diverse aquatic ecosystems (e.g. Amazon, Orinoquia) have been little studied. There is a critical need to revisit traditional indices, aiming at avoiding wrong assumptions about the relation between aquatic macroinvertebrates communities and water quality. For this purpose, it is recommended that assumptions and conditions required for using the indices, high taxonomic resolution, and new approaches, such as effective number of species, are taken into account.Keywords: aquatic insects, biotic indices, BMWP, diversity indices, lentic ecosystems, lotic ecosystems, water pollution.

Potential ecological and socio-economic effects of a novel megaherbivore introduction: the hippopotamus in Colombia

Abstract: Introduced species can have strong ecological, social and economic effects on their non-native environment. Introductions of megafaunal species are rare and may contribute to rewilding efforts, but they may also have pronounced socio-ecological effects because of their scale of influence. A recent introduction of the hippopotamus Hippopotamus amphibius into Colombia is a novel introduction of a megaherbivore onto a new continent, and raises questions about the future dynamics of the socio-ecological system into which it has been introduced. Here we synthesize current knowledge about the Colombian hippopotamus population, review the literature on the species to predict potential ecological and socio-economic effects of this introduction, and make recommendations for future study. Hippopotamuses can have high population growth rates (7–11%) and, on the current trajectory, we predict there could be 400–800 individuals in Colombia by 2050. The hippopotamus is an ecosystem engineer that can have profound effects on terrestrial and aquatic environments and could therefore affect the native biodiversity of the Magdalena River basin. Hippopotamuses are also aggressive and may pose a threat to the many inhabitants of the region who rely upon the Magdalena River for their livelihoods, although the species could provide economic benefits through tourism. Further research is needed to quantify the current and future size and distribution of this hippopotamus population and to predict the likely ecological, social and economic effects. This knowledge must be balanced with consideration of social and cultural concerns to develop appropriate management strategies for this novel introduction.