Browsing by Autor "Paul Van Damme"

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Abundancia, distribución y preferencias de nidificación de Podocnemis unifilis (Chelonia) en el río Ichilo, Cochabamba-Bolivia
(1999) Ximena Daza; Wanderfey Ferreira; Paul Van Damme; Edgar Goïtia
ABUNDANCE, DISTRIBUTION AND NESTING PREFERENCES OF Podocnemis unifilis (CHELONIA) IN THE ICHILO RIVER, COCHABAMBA - BOLlVIA Se realizo un estudio de la abundancia y distribucion de la tortuga acuatica Podocnemis unifilis en el rio Ichilo y se establecio la relacion entre parametros morlometricos del rio (ancho, profundidad y abundancia de troncos) y de las playas (area y altura) con la nidificacion de esta tortuga. Se obtuvieron los resultados a traves de datos de campo y de una imagen satelital Landsat TM de agosto de 1998, que fue tratada numericamente y luego analizada a traves de un SIG con los modulos especificos de software PMAP y PCI. La abundancia poblacional en 78 km de trayecto censado fue de 5.1 ind/km. Se encontro una relacion significativa positiva entre la altura promedio de cada playa y la cantidad de huellas encontradas en las mismas, como tambien una clara preferencia de nidificacion en las playas mas alejadas de actividades antropogenicas. Por ultimo, se entrega un mapa de abundancia y porcentaje de desoves de P. unifilis. Palabras clave: Podocnemis unifilis, nidificacion, morfometria, SIG, rio Ichilo, Cochabamba, Bolivia. ABSTRACT The abundance and distribution of the aquatic turtle Podocnemis unifilis were recorded in the river Ichilo, and the relation between river width and depth, abundance of logs, morphometry of the sand beaches (surface and height) on the one hand, and turtle nesting on the other hand was investigated. Data were obtained by in situ observation and through a Landsat TM satelite image of August 1998, which was numerically treated and then analysed through a SIG with the specific software PAMAP and PCI. The population density along 5 stretches of in total 78 km was 5.1 indlkm. A significant and positive relation was established between the average height of the sand beaches and the number of footprints recorded. There seemed to be a preference for remote beaches far away from antropogenic activity. A map indicating the abundance and the spatial distribution of turtles was elaboraded as well as of the distribution of nests of P. unifilis. Key words: Podocnemis unifilis, nesting, morphometry, GIS, Ichilo rivet; Cochabamba, Bolivia.
ACIDIFICACION DE RIOS POR CONTAMINACION CON METALES PESADOS EN LA ZONA ALTOANDINA BOLIVIANA: INDICADORES BENTONICOS
(1999) C. Hamel; Paul Van Damme
ACIDIFICATION OF RIVERS CONTAMINATED BY HEAVY METALS IN THE BOllVIAN HIGH ANDES: BENTHIC BIOINDICATORS El efecto de aguas acidas en rios contaminados con metales pesados sobre la estructura de comunidades de macroinvertebrados fue estudiado en rios altoandinos de Bolivia, en los departamentos de Potosi, Oruro y Cochabamba. Treinta muestras de bentos fueron coleccionadas en rios entre 2600 y 4500 m.s,nm, Se midieron los parametros fisicos y quimicos: oxigeno disuelto, pH, conductividad, alcalinidad, caudal y 000. Los datos fueron analizados a traves de indices de similitud (Jaccard), analisis de agrupamiento y analisis de componentes principales, Se observo que el pH en los rios estudiados fluctuo entre 2.86 y 8,98. Rios con pH 7); rios ligeramente acidos (6 7); slightly acid rivers (6 < pH <7), strongly acid (contaminated) rivers (pH < 4f Benthic taxa were classified preliminarly according to their grade of tolerance/sensibility to river acidification This study represents a first step towards the development of chemical indices and bioindices for acidification and heavy metal contamination in the Bolivian high Andes. Key words: Acidification, Bolivia, andean rivers, macroinvertebates, benthos, bioindication
ACUMULACION DE METALES PESADOS EN LOS SEDIMENTOS y EN LARVAS DE QUIRONOMIDOS DEL RIO CAINE (COCHABAMBA, BOLIVIA)
(1998) Danilo Solis; Ana Romero; Lieven Bervoets; Paul Van Damme
ACCUMULATION OF HEAVV METALS IN SEDIMENTS AND IN CHIRONOMID LARVAE IN THE RIO CAINE (COCHABAMBA, BOLIVIA) Se estudio el efecto de la actividad minera sobre la acumulacion de metales en sedimentos y quironomidos en el rfo Caine (zona Mina Asientos). En un estudio preliminar; fueron colectados sedimentos superficiales en 8 puntos de muestreo a lo largo del rfo y en un estudio posterior; se colectaron sedimentos superficiales asf como larvas de mosquitos (Chironomidae, Diptera) en 5 puntos de muestreo. Se determinaron las concentraciones de los metales cadmio, cobre, cromo, niquel, plomo y zinc en sedimentos y organismos, mediante espectrometrfa de absorcion atomica. En el primer estudio, se analizaron las concentraciones de metales totales y en el segundo estudio, las muestras de sedimentos fueron tratadas por dos diferentes metodos de extraccion para conocer la concentracion total de metales(T) y de metal reducido (R). No se detectaron incrementos significativos en la concentracion de metales en los sedimentos hasta 20 km rfo abajo del centro de actividad minera. Probablemente, los metales no se sedimentan por ser arrastrados por el agua. Sin embargo, la concentracion de metales en las larvas de mosquitos se incremento hasta 4 km rfo abajo. Probablemente, las larvas acumulan metales por el agua, a traves de una ruta que no ha sido cuantificada. Palabras claves: Metales pesados, Rfo Caine, bio-acumulacion, polucion de rios, Chironomidae, Cochabamba, Bolivia ABSTRACT The effect of mining on metal accumulation in sediments and chironomids in the Rfo Caine was assessed. In a preliminar stud)f: surficial sediments were collected at 8 sampling sites and, in a subsequent stud)f: surficial sediments and midge larvae (Chironomidae, Diptera) were collected at 5 sites. Concentrations of the trace metals Cd, Cu, Cr; Ni, Pb, and Zn were measured in sediments and organisms by atomic absorption spectrometer In the first stud)f: total trace metals were detected while, in the second stud)f: sediments were subjected to two different extraction procedures to measure total trace metals and reducible trace metals. No significant increase in metal concentration in sediments could be measured over a distance of 20 km downstream from the mining activitr Probabl)f: sedimentation of metals does not occur in this area and metals are being carried further downstream. However; larval metal concentrations increased markedly within the first 4 km of the area under investigation. Probabl)f: larvae accumulate heavy metals by a non-measured exposure route such as the overlying water column. Key words: Heavy metals, Rfo Caine, bio-accumulation, river pollution, Chironomidae, Cochabamba, Bolivia
ANÁLISIS DE CORRESPONDENCIA CANONICA VS. REGRESION MUlTIPlE: ¿PUEDEN MOSTRAR DIFERENCIAS ENTRE HIDROECOREGIONES?
(2003) Melina Campero; Paul Van Damme; Boris Arévalo; Dora Claros
La regionalizacion de ambientes acuaticos es una herramienta ampliamente utilizada por su capacidad de simplificar diferentes estudios en zonas muy extensas o megadiversas, como es el caso de Bolivia. Sin embargo, son pocos los estudios o los metodos que demuestren que tales regionalizaciones son validas a nivel biologico y no herramientas ficticias creadas por el hombre. En este estudio, comparamos el uso del Analisis de Correspondecia Canonica y del Metodo de la Regresion multiple para determinar la capacidad de ambas herramientas para diferenciar tres subcuencas, situadas en diferentes hidroecoregiones en el Departamento de Cochabamba. El estudio se realizo sobre comunidades de macroinvertebrados bentonicos en tres cuencas: Alto Beni, Chapar e y Caine (sub cuencas al interior de la Cordillera Oriental). Las variables medioambientales fueron escogidas bajo criterios morfologicos y bioclimaticos, Yo sobre estas bases de datos, se aplicaron ambos analisis (CCA y regresion multiple). El CCA diferencio de mane.ra poco precisa las tres sub cuencas. Por otro lado, el metodo de la regresion multiple establecio diferencias numericas detectables entre las tres subcuencas, con la ventaja adicional de predecir de manera correcta la fauna al interior de la cuenca Alto Beni. Creemos que este metodo puede ser el mas efectivo al aplicarse, tanto en estudios de regionalizacion como de biomonitoreo. Palabras claves: Regionalizacion de ambientes acuaticos, regresion multiple, Analisis de Correspondencia Canonica, Bolivia. ABSTRACT Establishing ecoregions for aquatic environments is common because is simplifies studies in extents regions or were mega diversily exists, as is the case in Bolivia. Howevet; few studies have validated the method of delimitate ecoregions for biological studies. We compare the capacity of Canonical Correspondence Analysis and Multiple Regression to differentiate between three basins, located in different hydro-ecoregions in the State of Cochabamba. We studied macroinvertebrate communities from the Alto Beni, Chapare, and Caine basins (in the ecoregion of Andean Cordillera-Oriental Sector). The environmental variables were chosen based on bioclimatic and geomorpholgical Griteria. CCA and Multiple Regression were applied to both databases. The CCA did not differentiate the three basins clearlr Howevet; the Multiple Regression Method established significant differences between the three ba,sins and also predicted the fauna in Alto Beni basin. Thus, we conclude that Multiple Regression is more effective in identifying ecoregions and a more adequate tool for biomonitoring studies. Keywords: Establishment of ecoregions, Multiple Regression, Canonical Correspondence Analysis, Bolivia
Clasificación de Cuencas de Bolivia según la metodología de Pfafstetter / Classification of river basins of Bolivia using the method of Pfafstetter
(2013) Álvaro Martínez Crespo; Paul Van Damme; Milton Zapata
Hasta el momento, las cuencas en Bolivia no han sido clasificadas con un sistema estandar. Las clasificaciones existentes son subjetivas y generalmente no aplican sistemas de jerarquizacion. En este trabajo se aplico el metodo de Pfafstetter, reconocido a nivel mundial, el cual es de caracter numerico, topologico y natural porque sigue la direccion del drenaje del agua. Se ha podido clasificar las cuencas hasta el octavo nivel en algunos sistemas y para todo el territorio hasta el cuarto nivel. Se presenta un mapa de cuencas combinando diferentes niveles, y se discuten las posibles aplicaciones. Palabras clave: Cuencas, Pfafstetter, Bolivia, Clasificacion. ABSTRACT There does not exist a standard classification system for river basins in Bolivia. Most of the existing classification systems are subjective and do not consider hierarchical ranking of river basins. We present a classification system based on the Pfafstetter method, recognized internationally as a standard. This methodology is numerical, topological and natural because it follows the direction of the drainage water. Watersheds were classified until the eighth level in some regions and until the fourth level in the whole territory. We present a map combining different levels, and discuss possible applications. Key words: River basins, Pfafstetter, Bolivia, Classification
Contaminación orgánica en el río Rocha (Cochabamba, Bolivia)
(1998) Ana Romero; Paul Van Damme; Edgar Goïtia
Contaminación y eutrofización en la cuenca del río Rocha (Cochabamba)
(1998) Mabel Maldonado; Paul Van Damme; José Alejandro Romero Rojas
Diversidad acuática en la zona de influencia de un campo de gas y petróleo en la provincia Carrasco (Cochabamba, Bolivia)
(2000) Franklin Horacio Lozada Maldonado; Paul Van Damme; R. Sanabria; Fabio Araya Carvajal; Carlo Vandecasteele; Joel Rojas Acuña
AQUATIC DIVERSITY IN A RIVER ADJACENT TO A GAS AND PETROLEUM EXPLOITATION SITE IN THE PROVINCE CARRASCO (COCHABAMBA, BOLIVIA) El rio Izozog (Carrasco, departamento de Cochabamba) recibe desechos liquidos difusos de la actividad petrolera desarrollada en la zona. La diversidad acuatica en este rio fue estudiada, y los impactos posibles de contaminacion por los derrames sobre la diversidad acuatica fueron investigados. El efecto sobre la calidad del agua es poco apreciable tanto en epoca de estiaje como en periodo de lluvias: unicamente en la zona de muestreo rio abajo de las descargas, se detecto un incremento en conductividad, D00 (Demanda Quimica de Oxigeno) e Hidrocarburos Totales. Macroinvertebrados bentonicos fueron muestreados con un surber sampler en rapidos y con una draga Van Veen en pozas. La comunidad de peces fue muestreada con un equipo portatil de pesca electrica (Smith-Rooth) en rapidos. Los macroinvertebrados bentonicos del rio Izozog pertenecen a 19 familias. Los 497 peces que fueron capturados pertenecen a 17 taxas. Characidae y Loricariidae fueron las familias mejor representadas tanto en terminos de numero de especies como en numero de individuos. B imii>8cto de la contaminacion se evidencio sobre las comunidades de bentos rio abajo del area de contaminacion difusa durante la epoca seca; sin embargo, en epoca de lluvias el efecto sobre el bentos no fue significativo. No hubo un impacto detectable de la contaminacion sobre los peces. Empero, fue dificil discriminar entre variaciones naturales y cambios inducidos por contaminacion. Una discusion sobre estrategias de muestreo para detectar impactos ambientales esta incluida. Palabras clave: Contaminacion, petroleo, bentos, peces, rio Izozog, Cochabamba, Bolivia. ABSTRACT The Izozog River receives contaminated water from a number of non-point sources, generated by oil exploration activities in the Carrasco Province of the State of Cochabamba. The aquatic diversity in this river was studied and possible impacts of oil contamination on aquatic diversity were assessed. In general, the effect on water quality was minor in both the rainy and dry season. Only in samples collected downriver from the pollution source, was an increase in conductivity, 00D (Chemical Oxygen Oemand), and Total Hydrocarbon Concentration observed. In rapids, the benthic macroinvertebrates were sampled with a surber sampler while in pools, a Van Veen sampler was used. In rapids, the fish community was sampled with a portable electrical fishing apparatus (Smith-Root). The benthic macroinvertebrates recorded in the Izozog River belonged to 19 different families. A total of 497 fish, belonging to 17 different taxa, were collected. In terms of species number and number of individuals, Characidae and Loricariidae were most numerous. The impact of the contamination on the benthic community in the sample point immediately downstream from the non-point contamination sources was observed during the dry season, whereas the impact on the fish community was never detectable. The overall impact during the rainy season was small. However; it was difficult to distinguish between natural variation and contamination-induced changes in community structure. A discussion on sample strategies to detect environmental impacts of petroleum contamination is also presented. Key words: Contamination, petroleum, benthos, bio-indication, river Izozog, Cochabamba, Bolivia.
Fisheries of the scavenger species Calophysus macropterus: a case study in the Bolivian Amazon
(2023) Paul Van Damme; Paul Van Damme
Bolivian Amazon small-scale fisheries traditionally focus on large migratory fish species. However, in the last decade there has been a trend of increased landings of low-value medium-sized migratory species, such as blanquillo, Calophysus macropterus. This scavenger species is captured using chicken and bovine waste as bait, and occasionally carcasses from wild species. This study explores the boom of this specialized fishery in Puerto Villarroel, a small harbor on the Ichilo River, using a combination of historical landing data, fisheries statistics obtained by participatory fisheries monitoring, fish market studies and interviews with local key stakeholders. Additionally, mercury contamination of fish meat was evaluated. Blanquillo fishing started in 2008 and boomed around 2015, representing 30% of landings, after which it decreased to fluctuate around 15%. The capture and landing data suggest that this species is mainly captured by non- organized fishers. The market studies conducted between 2015 and 2018 in Cochabamba city and in lowland middle towns showed that on average more than 20% of consumption of Amazon river fish consisted of blanquillo meat. Mercury is accumulated in the muscle tissue at concentrations near the official limit established by WHO for human consumption, whereas in 15% of fish the concentrations exceeded this limit. The paper pieces together the evolution of the blanquillo fishery in Bolivia, and looks at different aspects, including the diversity of fishers involved, possible impacts on other vulnerable species and public health, and potential impacts and effectiveness of different public policy approaches. In conclusion, the present study shows there is an overall need for more consistent and inclusive fisheries regulations in the Bolivian Amazon, as a way to protect aquatic fauna, avoid environmental contamination and secure human health.