Cyanobacterial blooms have serious adverse effects on human and environmental health. In Latin America, one of the main world's freshwater reserves, information on this phenomenon remains sparse. To assess the current situation, we gathered reports of cyanobacterial blooms and associated cyanotoxins in freshwater bodies from South America and the Caribbean (Latitude 22° N to 45° S) and compiled the regulation and monitoring procedures implemented in each country. As the operational definition of what is a cyanobacterial bloom remains controversial, we also analyzed the criteria used to determine the phenomena in the region. From 2000 to 2019, blooms were reported in 295 water bodies distributed in 14 countries, including shallow and deep lakes, reservoirs, and rivers. Cyanotoxins were found in nine countries and high concentrations of microcystins were reported in all types of water bodies. Blooms were defined according to different, and sometimes arbitrary criteria including qualitative (changes in water color, scum presence), quantitative (abundance), or both. We found 13 different cell abundance thresholds defining bloom events, from 2 × 10³ to 1 × 10⁷ cells mL^-1. The use of different criteria hampers the estimation of bloom occurrence, and consequently the associated risks and economic impacts. The large differences between countries in terms of number of studies, monitoring efforts, public access to the data and regulations regarding cyanobacteria and cyanotoxins highlights the need to rethink cyanobacterial bloom monitoring, seeking common criteria. General policies leading to solid frameworks based on defined criteria are needed to improve the assessment of cyanobacterial blooms in Latin America. This review represents a starting point toward common approaches for cyanobacterial monitoring and risk assessment, needed to improve regional environmental policies.

Ypacaraí Lake is the most renowned lake in landlocked Paraguay and a major source of drinking and irrigation water for neighbouring towns. Beyond its socioeconomic and cultural significance, it has great ecological importance, supporting a rich biodiversity. Rapid growth of human presence and activities within its basin has led to its environmental degradation, a heartfelt matter of high political concern that compels intervention. Here, by reconstructing the history of scientific and management-oriented research on this system, we provide a comprehensive assessment of current knowledge and practice to which we contribute our recent, novel findings. An upward trend in total phosphorus concentration confirms ongoing eutrophication of an already eutrophic system, evidenced by consistently high values of trophic state indices. Downward trends in water transparency and chlorophyll-a concentration support the hypothesis that primary production in this lake is fundamentally light limited. Statistical and other analyses suggest high sensitivity of the system to hydraulic, hydro-morphological and hydro-meteorological alterations arising, respectively, from engineering interventions, land use and climate change. By discussing knowledge gaps, opportunities for research and challenges for management and restoration, we argue that this case is of high scientific value and that its study can advance theoretical understanding of shallow subtropical lakes.

Trichoderma, un género de hongos filamentosos es ampliamente utilizado en la agricultura debido a sus propiedades y usos diversos, destacando su habilidad para funcionar como un agente biocontrolador contra diversos fitopatógenos. El éxito de Trichoderma se basa en múltiples mecanismos de acción, que incluyen antibiosis, micoparasitismo, competencia por espacio y nutrientes, producción de enzimas y metabolitos secundarios con actividad antimicrobiana y la estimulación de la respuesta de defensa de las plantas ante los patógenos. Esta mini revisión se centra en los mecanismos de acción de Trichoderma como biocontrolador y sus potencialidades para el uso en la agricultura. Este género de hongos filamentosos con capacidad para inhibir el crecimiento de patógenos, estimular el crecimiento de las plantas y mejorar la calidad del suelo lo convierten en un recurso valioso para los agricultores. El conocimiento de estos mecanismos puede ayudar a mejorar aún más su uso en la agricultura y promover prácticas agrícolas sostenibles.

The objective of this research project was to evaluate the implementation of a phytoremediation system for the effluents generated by the National Cancer Institute (INCAN), Central Department, Paraguay to contribute to the management of the liquid waste that it generates. The system consisted of...

El zooplancton es un integrante importante dentro de la comunidad biótica en un ecosistema acuático ya que actúan como bioindicadores, es por eso que el objetivo del presente trabajo fue determinar el efecto de los factores ambientales sobre la diversidad zooplanctónica en las lagunas del Parque Ñu Guasú. Para ello se tomaron muestras de agua, se midieron in situ el pH, la conductividad, la temperatura y el oxígeno disuelto y en el laboratorio la DBO₅, la DQO, la turbidez, el Nitrógeno Total y el Fósforo Total. Para los análisis biológicos se determinaron la riqueza específica y la abundancia y se emplearon el coeficiente de correlación de Pearson y el análisis de redundancia canónica (RDA). Se registraron diez morfotaxas siendo los rotíferos los más abundantes. Se identificaron 8 especies en la Laguna 1 y 7 especies en la Laguna 2. La abundancia en la Laguna 1 y 2 fue de 90 y 87 individuos respectivamente. Los factores ambientales tuvieron mayor influencia sobre las especies en la Laguna 1 fueron el Fósforo Total, la transparencia y la temperatura frente a Philodina sp. Macrothrix elegans y Sida crystallina, mientras que en la Laguna 2, el Nitrógeno Total, el Fósforo Total y el pH tuvieron mayor relación con las especies Keratella cochlearis, Alona sp., Sida crystallina y Eudiaptomus gracilis concluyendo la comunidad de zooplancton de ambas lagunas respondió de distinta manera a los factores ambientales.