Plankton Community Responses to Anthropogenic Pollution in an Argentinian Urban Reserve

VASCHETTO, PABLO; ANDRADE, VICTORIA; REGALDO, LUCIANA; GERVASIO, SUSANA; POLLA, WANDA; GAGNETEN, ANA MARÍA

WATER AIR AND SOIL POLLUTION

SPRINGER

Año: 2021 vol. 232

0049-6979

This study highlights the monitoring and management of urban water bodies, focusing on plankton biodiversity and its relationship with surface water quality. Physicochemical parameters and concentrations of potentially toxic metals were evaluated in an urban reserve in the Central East of Argentina, created for urban flood risk management. During 1 year, in seasonal samplings, environmental parameters, nutrients, chemical oxygen demand (COD), biological oxygen demand (BOD5), and concentrations of potentially toxic metals (Cu, Cr, Pb, and Cd) in water and benthic sediments were analyzed in four sampling sites. The heavy metal geo-accumulation index (Igeo) was also calculated. Quali-quantitative analysis of phytoplankton and zooplankton samples was performed and summarized in ecological attributes and indices: Total density, specific richness, Shannon?s diversity index, Simpsons? dominance index, and evenness index, as well as phytoplanktonic biovolume and functional groups. Except Cu, metal concentrations in water exceeded recommended limits for freshwaters in 37.5% (Cr), 31.3% (Pb), and 18.8% (Cd) of samples. Igeo revealed that sediments were moderately, highly, and very seriously polluted with Cu, Cr, and Pb, respectively. Phytoplankton showed the predominance of functional groups typical of eutrophic and low-flow environments, with high concentrations of nutrients. Cyanobacterial blooms occurred in 75% of the samples, considered high-risk events for the aquatic life and users of the urban reserve. The zooplankton community was dominated by microzooplankton, characterized by smaller species, more tolerant to polluted and eutrophic waters. This survey evidences the urgent need to develop a comprehensive management plan for the area.