Phytoplankton composition from Araca Bay and Sao Sebastiao Channel, Sao Paulo, Brazil

Author(s)

Tocci, B. R. C. ; Moser, G. A. O. ; Ciotti, A. M.

• Document type: Journal article
• Source: Biota Neotropica; v. 23, n. 2, p. 12-pg., 2023-01-01.

Abstract

Despite its small area, Araca Bay (AB) holds cultural, historical, and economic value and displays great benthic biodiversity. Thus, it is crucial to monitor its environmental health, including knowing the main groups of phytoplankton and their temporal variability. The shallow waters of Araca Bay are continuously modified by the complex hydrography of the adjacent Sao Sebastiao channel (SSC), challenging standard experimental designs for phytoplankton collection. Here we report changes in phytoplankton composition at intervals of five to six weeks from September 2013 to August 2014 in both Araca Bay and SSC. Samples were collected twice daily for three consecutive days to increase taxonomic resolution. Our goal was to provide an inventory of species occurrences to aid future public policies and environmental management of the area. Analyses revealed high species richness and 166 different phytoplankton taxa. Diatoms and dinoflagellates were always numerically dominant, but taxa occurrence changed markedly. Diatoms of the genera Pseudo-nitzschia were abundant during spring and summer concurrently to signatures of South Atlantic Central Water in the SSC, while Thalassiosira occurred when waters displayed relatively lower salinity. The inventory demonstrated several potentially harmful species of microalgae and cyanobacteria, strongly suggesting investments in monitoring programs in this area that currently experience an increase in population. (AU)

• FAPESP's process: 11/50317-5 - Biodiversity and functioning of a subtropical coastal ecosystem: a contribution to integrated management
• Grantee: Antonia Cecília Zacagnini Amaral
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants