Environmental factors driving phytoplankton biomass and diversity in a tropical reservoir

Abstract

We determined the spatial and temporal variation of phytoplankton biomass and diversity in 10 fortnightly sampling journeys verifying five sampling sites in El Peñol-Guatapé reservoir located in Antioquia, Colombia. In situ and ex situ physical and chemical variables were measured and phytoplankton samples were taken. Richness was dominated by Chlorophyta and biomass by Dinophyta. This variable was higher in the transition zone while in the riverine zone it showed average values, the lowest were registered in the lacustrine zone. Diversity was lower in the riverine zone, but it increased considerably in the transition zone and in the lacustrine zone where it showed similar values. At the vertical scale, biomass and diversity did not vary widely. Biomass showed a differential response to the effect of precipitation changes and water levels in the reservoir zones. Due to the low variability in environmental conditions, diversity was homogeneous time-wise. These results suggest that factors related to the hydrodynamic such as precipitation and water level resulting from the dam operation and inflow have a slight influence on the temporal variations of phytoplankton biomass and structure. There was a direct relationship between these attributes and physical variables such as turbidity and nutrients concentration at spatial scale while at the vertical scale, mixing patterns and the influence of the wind explained the absence of the vertical gradient of biomass and phytoplankton structure.

Interactions between Aquatic Plants and Cyanobacterial Blooms in Freshwater Reservoir Ecosystems

“…The river sections of the reservoirs are characterized by inputs of large amounts of nutrients, but light attenuation and general lotic conditions limit cyanobacterial growth, in agreement with the results of similar studies [81,82,84,86,89,90]. On the other hand, in the middle (transitional) and lower (lake) areas of reservoirs, conditions such as slowing down of water-flow speed, higher sedimentation of suspended solids, and, as a result, higher transparency, better penetration of light through the water column, and heating of water masses favour cyanobacterial growth.…”

“…On the other hand, in the middle (transitional) and lower (lake) areas of reservoirs, conditions such as slowing down of water-flow speed, higher sedimentation of suspended solids, and, as a result, higher transparency, better penetration of light through the water column, and heating of water masses favour cyanobacterial growth. Moreover, higher nutrient concentrations and ratios contributed to an increase in phytoplankton abundance and species richness, in particular of cyanobacterial species, as also found in previous studies [79,81,84,89,90]. Canonical correspondence analysis (CCA) showed that higher concentrations of nitrogen compounds and lower concentrations of phosphorus compounds contributed to the increase in phytoplankton biomass.…”

“…The results of the investigations conducted in nature reveal significant spatial variations in the quantitative (number of cells, biomass, and concentration of chlorophyll a) and qualitative (species composition) features of the phytoplankton in the ecosystems of the Kyiv and Kaniv Reservoirs; this trend can also be traced in earlier studies [78][79][80][81][82]. In reservoirs, such elements of hydrodynamics as flow speed, mixing, wave processes and water-level fluctuations are the main factors that influence physical and chemical conditions and determine phytoplankton biomass and diversity [79,80,[83][84][85][86][87][88][89][90][91]. During the research period, phytoplankton biomass was mainly formed by cyanobacteria and diatoms.…”

Interacciones e inestabilidad del plancton en cuatro embalses tropicales con diferente estado trófico

“…Interaction between the instability of the physicochemical variables and the instability of zooplankton density (based on artificial intelligence algorithms from the FCA analysis). Como se ha encontrado en diferentes estudios (Gil-Guarín et al, 2020;Ríos-Pulgarín et al, 2020), la comunidad fitoplanctónica de los embalses está estrechamente relacionada con la disponibilidad de nutrientes esenciales, como el nitrógeno para la síntesis de proteínas y la producción primaria (Roldán & Ramírez-Restrepo, 2022). En este sentido y según lo encontrado por Unrein (2001), el incremento en la densidad de Cryptomonas sp.…”

“…Trabajos basados en modelos estadísticos multivariados (Gil-Guarín et al, 2020;Pineda et al, 2022;Villabona-González et al, 2020) explican cómo las comunidades planctónicas responden a la variabilidad ambiental en los embalses. Frecuentemente estos estudios han empleado análisis estadísticos clásicos como Métodos: Se analizaron datos de variables físicas y químicas y de las densidades del fitoplancton y del zooplancton, medidas entre 2010-2018, en los embalses oligotróficos Punchiná y San Lorenzo y, entre 2013 y 2015, en el embalse hipereutrófico Porce II y en el embalse eutrófico Porce III (total N = 248).…”