Seasonal flowering of Ulva lactuca Linnaeus (Chlorophyta) near a phosphate fertilizer unloading terminal in Paranaguá Bay – PR Fernanda Ribeiro Freitas, Rayane Silva Bueno, Karina Gonçalves Capete

Abstract

Leafy macroalgae belonging to the genus Ulva are capable of absorbing high concentrations of nitrogenous and phosphate compounds dissolved in seawater, in addition to tolerating sudden variations in physical and chemical parameters of the environment in which they are located, being potential organisms in reducing eutrophication, acting as biofilters and environmental indicators. Eutrophic environments are conducive to the development of unispecific algal beds, characterized by an excessive increase in biomass in a short period of time. In this work, the population dynamics of a U. lactuca bank in front of a phosphate fertilizer unloading terminal located in the port complex of Paranaguá Bay (BP), southern Brazil, was evaluated. The BP Estuarine Complex has an area of ​​601 km2, with 456 km2 bordered by mangroves, areas of great ecological relevance. Macroalgal biomass was monitored monthly, through destructive random sampling during spring tides. The recorded data suggests that the accumulation of biomass in winter campaigns may be associated with low temperatures and the input of nitrogenous compounds, in which phosphate compounds did not appear to contribute effectively to the increase in algal growth.