Spring 2008 Seminar Series

Dr. Steven Colbert

Abstract

Phytoplankton blooms commonly occur in coastal waters when nutrients (e.g. ammonium, nitrate, phosphate) are available.  While most blooms are benign, some are toxic or otherwise harmful to marine life.  To predict which algal species will bloom, the availability and composition of nutrients must be known.  In this talk, I will characterize the input of nutrients to San Pedro Bay, CA, from seawater flowing through permeable shelf sediments.  During much of the year, seafloor nutrient inputs equal or exceed local river inputs.  Seawater circulation through the seafloor also alters the composition of nutrients as nitrate is removed by denitrification.  Overall, predicting nutrient fluxes is a multidisciplinary endeavor, requiring physical models of sand ripple formation by waves and ecosystem models of the supply of organic carbon to the seafloor.