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Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phytoplankton biomass is a variable used in ecological studies and in monitoring potentially toxic cyanobacterial blooms. Biomass indicators of this community range from general and indirect, such as chlorophyll a concentrations, to specific and quasi-direct measures such as biovolume. Based on the results of a survey addressed to Latin American scientists and technicians as well as a bibliographic search, we discuss the relevance of using biovolume as the most appropriate indicator of biomass, the effort of quantifying phytoplankton using different counting units and the implications for interpretation of the results. Individuals, cells and biovolume were the quantitative units used to report phytoplankton. The individual represents the natural biological unit of the organism (cells, coenobia, colonies or filaments) and has a wide size range. We strongly advise that the phytoplankton reported as individuals per unit volume can lead to conceptual misinterpretation, such as the underestimation of the biomass of blooms. As cells have a large variation in their sizes, it poorly correlates with biovolume or chlorophyll a concentration. Considering all these aspects is crucial when selecting quantitative bioindicators to monitor potentially toxic cyanobacteria. We strongly recommend the use of biovolume as a biomass indicator for phytoplankton in general and consider it imperative for monitoring cyanobacteria. [ABSTRACT FROM AUTHOR]

Copyright of Ingeniería del Agua is the property of Universidad Politecnica de Valencia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study of the functioning of the high Andean ecosystems is of great importance since any change will influence the entire basin. However, knowledge of these environments is still limited. Therefore, we sought to determine the effect of seasonality on the macrobenthos assemblage of a high Andean River and to determine the limnological, geomorphological, and hydrologicalhydraulic variables that most influence it. In the El Salto River, located 4,500 meters above sea level, in high Andean environments in southern Peru, macrobenthos was collected in 2020 in 11 hydro morphological units, recording limnological variables (dissolved oxygen, saturation percentage, conductivity, TSD, temperature, pH, turbidity and SS), geomorphological (granulometry) and hydrological-hydraulic (flow, velocity, depth, channel width) in dry and wet seasons. The principal component analysis (PCA) of the physicochemical variables showed that the flow rate, conductivity, pH, and total dissolved solids explained the greatest variability of the data (70 %). The predominance of boulders and silt was found. The number of species and density were higher in the dry season than in the wet season. However, the diversity, richness, and equity were higher in the wet season. The ordination analysis (nMDS, stress=0.09) showed a different structure of the macrobenthic assemblage between both seasons. It is concluded that seasonality, given by various factors, mainly flow rate and flow velocity, determine variations in the macrobenthos assemblage, confirming the drastic changes to which these high Andean ecosystems with extreme climates are subjected. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Laguna del Caney in the Municipality of Chinácota, Norte de Santander, Colombia, is a place frequently visited by different species of birds, especially some ducks and herons. It’s due the birds find food and a place to rest and reproduce. However, the community of birds that visit this lagoon is unknown. Thus, both bird diversity and its community structure were determined through a rapid sampling of direct observation. The specific diversity of bird species was obtained, this was 19, which are grouped into 9 orders and 13 families. The most common species was Dendrocygna autumnalis (38%), followed by Jacana jacana (17%) and Columbina talpacoti (10%). In addition, the Shannon diversity was found to be 8.59, and the Simpson diversity was 5.11. Also, for the first time, the duck species Anas andium (3%) is reported in a lagoon located at an altitude of 1000 m.a.s.l. In Colombia. Currently, the factors that may be influenced the behavior of the species are unknown, so this work opens the door to new ecological research on this species of waterfowl. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Los ríos altoandinos presentan presiones antrópicas por la necesidad de abastecimiento de agua debido al crecimiento demográfico. En ese sentido, los elementos bióticos asociados a estos sistemas como la vegetación acuática y semiacuática, pueden verse afectados dados los cambios que la actividad humana ocasiona sobre las corrientes naturales de montaña. La presente investigación se desarrolló en tres ríos, en jurisdicción del municipio de El Carmen de Viboral en el departamento de Antioquia, se establecieron cuatro muestreos para las tres estaciones, se midieron algunas variables fisicoquímicas para determinar su influencia sobre la estructura de la comunidad de hidrófitos. Se encontró que las variables más influyentes sobre la vegetación fueron caudal, pH, conductividad eléctrica, nutrientes, temperatura del agua y turbiedad. Por lo anterior se corroboró la hipótesis planteada, de que las variables fisicoquímicas influyen en la distribución de plantas acuáticas en los ríos andinos. [ABSTRACT FROM AUTHOR]

Copyright of Dynamis is the property of Dynamis - Facultad de Medicina de la Universidad de Granada and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In April 2003, there was an oil spill in the Papallacta zone (Ecuador: northern Andes), after the disaster bioremediation work was carried out in the lagoon and in its tributaries. We analyze the phytoplankton community as bioindicator of the current quality of the water body, considering 28 places in tributaries and in the lagoon, both in the dry season, transitional and rainy season, from December 2010 to July 2011, we identified and counted the genera of phytoplankton found in each sampling point, also considering the natural history of each group of algae. Diatoms, cyanobacteria and green algae were the major groups, the first of them was the most widely distributed with higher values in richness and abundance. The correlations between genera and abiotic variables showed differences related to seasonality. However, there was the constant presence of certain genera as Synedra and Oscillatoria, high organic load indicators. This research also provides information about the genera that now dominate both in the lagoon and its tributaries and the characteristics that influence their distribution and allow to determine the ecological health of Laguna de Papallacta, now it can be classified as mesotrophic. The presence of oil is restricted on specific points on the bottom of the lagoon, allowing that primary productivity in the photic zone develops normally. [ABSTRACT FROM AUTHOR]

Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Morphological, physical and chemical characteristics of urban lakes of Conception were studied. The results indicate that these lakes are in an advanced process of eutrophication caused by excessive anthropogenic nutrient loads (mainly phosphorus and nitrogen). Furthermore, high concentrations of faecal and total coliforms in the water column and heavy metals in the sediments of these lakes were recorded. The principal component analyses showed that total phosphorus, ammonia, pH, conductivity, transparency and chlorophylla, are the variables that best explain the water conditions of all the lakes studied. It is recommended to orientate the lake management actions to decrease total phosphorus. Considering the particular situation of each lake, a series of complementary measures for reversing the current situation should be applied. This study provides new limnological information for the decision-making process focussed on the recovery of urban lakes of the City of Concepción. [ABSTRACT FROM AUTHOR]

In order to evaluate the quality of the water of the Locumba river, Tacna (Peru), water samples were taken from ten stations located along the Locumba river basin, during six periods in an annual cycle. The diversity and number of diatoms was also evaluated, together with eleven physiochemical parameters in order to determine the degree of water contamination. We found that as the basin advanced down the mountain, the diversity of diatoms decreased from 2.37 bits cell-1 to 0.71 bits cell-1 and the gradient of contaminants increased. In addition to this increase, the number of species tolerant to high levels of environmental disturbance rose. An increase in all physiochemical parameters used to evaluate the degree of contamination was observed. These results suggest that diatoms can be adequate bioindicators when evaluating the quality of water in this basin. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Científico Centro de Museos de Historia Natural is the property of Universidad de Caldas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)