Limnological characteristics and planktonic diversity of five tropical upland lakes from Brazilian Amazon

Abstract

A limnological investigation involving physical, chemical and biological aspects was undertaken in five tropical upland lakes (Violão À Vl, Amendoim À Am, and Três Irmãs À TI1, TI2 and TI3) from Serra dos Carajás, Brazil. Results show that these lakes are shallow, weakly stratified, and of polymictic type. These characteristics may have caused vertical mixing of limnological parameters. Seasonal changes were minor for most parameters, except for chlorophyll-a (Chl-a) and cyanobacteria, which also showed considerable variation between lakes. In general, waters of these lakes were mostly acidic in nature (avg. pH 4.9-5.9), with high total Fe (up to 1.52 mg/L) and low electrolytic conductivity (avg. 8.13-14 mS/cm) and total phosphorus (TP) (avg. 10-35.5 mg/L). Although the water bodies have good quality and classified as class I and II types according to CONAMA Resolution No. 357/05, trophic state index (TSI) varies from ultra-oligotrophic to eutrophic state, with higher trophic state observed for Vl, TI1 and TI2. Limnological characteristics of these lakes is highly influenced by lithological and morphological parameters. Principal component analysis (PCA) reveals that Chl-a and cyanobacteria are not solely influenced by TP and lower concentrations of all these parameters in Am lake are probably due to specificities of its catchment lithology. Phytoplankton taxa in the lakes are characterized by small chroococcales groups and desmids together with filamentous algae, more commonly observed in the dry season. The zooplankton community in the lakes is mainly dominated by rotifers, followed by cladocerans and copepods. Regarding species richness, zooplankton was highest in Vl, while phytoplankton is highest in TI1, and this aspect is most likely related to lake water levels.

Upland Lakes of the Carajás Region: Origin and Development through Time

“…In closed lake basin, local geology and seasonal climate are the major factors controlling the physical and chemical characteristics of waters such as temperature, thermal stratification, lake levels and nutrient availability (Catalan and Rondon 2016;Sahoo et al, 2017b). These parameters can have a significantly influence on lake trophic states, phytoplankton assemblage as well as the overall planktonic abundance (Molisani et al, 2010).…”

“…The ULs sediments are highly influenced by natural and local characteristics of each catchment basins, including parent rock properties, source-area weathering, rheology, morphology and vegetation cover, as well as the primary productivity of the central basins (Sahoo et al, 2015(Sahoo et al, , 2016a(Sahoo et al, , 2017a. The interrelation of these factors have controlled the geochemical and limnological characteristics of these lakes through time (Sahoo et al, 2017b). In general, ULs present thick Quaternary deposits with relatively continuous records of paleoenvironmental changes, as such observed in the Morro dos Seis Lagos (northwestern Amazonia), Serras de Maicuru and Maraconaí (northestern Amazonia), and dos Carajás (southeastern Amazonia) (Colinvaux et al, 2001;Bush et al, 2004;Sifeddine et al, 2001;Guimarães et al, 2016;.…”

Nível de referência dos elementos associados à mineração de Fe, Ni e Cu em lagoas do platô S11 na região de Carajás (águas superficiais)

“…Estas CGFs apresentaram algumas variações entre os períodos secos e chuvoso, com as maiores CGFs de Al_d, Al_t, and Zn observadas no período chuvoso, enquanto que o Fe foi maior no período seco. Entretanto, este enriquecimento pode ser fortemente influenciado por processos geogênicos com o intemperismo das bacias de drenagens das lagoas (SAHOO et al, 2017). Figura 10 -Box-plot juntamente com o diagrama Q-Q mostrando a distribuição de Ba e Al_t, bem como valores anômalos no período seco.…”

“…Estas lagoas são isoladas da influência fluvial, e são situadas em um sistema de bacias de contribuição restritas ou fechadas formadas por processos estruturais e intempéricos dos perfis da canga . Conexão superficial é somente observada no sistema Três Irmãs (SAHOO et al, 2017).…”

Water quality assessment of a temperate urban lagoon using physico-chemical and biological indicators

“…The phytoplankton assemblage changes can reflect the presence of pollutants, especially nutrients [41] which cause an increase in the micro-phytoplankton abundance [1,52] and in the tolerant species [56] and a decrease in the sensitive species [26]. These assemblages are good indicators due to respond quickly to ecological changes, due to their fast growth rates [32,75,84,87] and permit detecting any possible alteration in water quality [13,23,54,75]. Traditional phytoplankton monitoring is based on biomass, chlorophyll-a or accessory pigments and composition and abundance of species [2,7,31,53].…”