The influence of wave regime in phytoplankton biomass present in São Vicente bay.

• Grant number: 08/00699-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2008
• End date: December 31, 2008
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Aurea Maria Ciotti
• Grantee: Renato de Traglia Tonini
• Host Institution: Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Ecological information regarding the general biological productivity in estuaries is of extreme importance, as these environments are highly productive and potentially affected by human activities. Estuaries hydrodynamics are regulated by tidal flow, continental runoff, wind and wave fields, where the main primary producers, phytoplankton, respond rapidly to physical changes that regulate both nutrient and light availability. In estuaries that are eutrophic, light can become the limiting factor to phytoplankton growth and hence biomass accumulation. In this work, we will quantify the chlorophyll-a concentration, weekly, and verify its relationship with wave height and water transparency. Three points will be sampled with a small boat at slack water levels during the ebb and flood tides. This sampling strategy allows comparing observations at different stages of the tidal cycle and during distinct sea states resulting from the action of waves and local winds. Our hypothesis is that wave action in São Vicente bay will decrease chlorophyll-a concentration due to light limitation, and their effects are comparable to those originated by rainfall and tidal currents.