Sienna White

Water quality in the San Francisco Bay Delta affects regional water resources, ecosystem health, and quality of life for any of the two million people who interact with the Delta or call its shores home. However, water management in the Delta has become a heavily politicized issue, as large-scale water withdrawal for agriculture and state water projects often comes at the cost of ecosystem protection measures.

The Delta receives large inputs of anthropogenic nutrients from wastewater treatment plants which result in elevated dissolved inorganic nitrogen levels (Novick et al., 2015). This nutrient-enriched status places the Delta at high risk for algal blooms (Paerl, 2009; Dahm et al., 2016), including risk for bloom events with toxic, or harmful algal species (commonly referred to as harmful algal blooms, or HAB events). These harmful algal blooms threaten public health and endanger the potability of the water supply. Furthermore, climate change, reduced sediment load, and increased nutrient delivery have accelerated algal bloom activity, resulting in increased harmful algal bloom events (Lehman et al., 2017).

My PhD research will focus on using numerical models to investigate the specific mechanisms that precipitate harmful algal blooms, which likely involves a "goldilocks zone" of wind-driven mixing, tidal forcing, river outflow, nutrient supply, and temperature. Better understanding what conditions allow Microcystis (a harmful algal species) to dominate over "beneficial algal species" (diatoms) will then be used to inform a prediction framework, providing water managers with much-needed visibility of where (and when) harmful algal blooms are likely to occur.