Use Care When Interpreting Correlations: The Ammonium Example in the San Francisco Estuary

Abstract

THE PARADOX OF A HIGH–NUTRIENT, LOW–PRODUCTIVITY ESTUARY Early studies of the San Francisco Estuary (estuary) revealed a paradox of high concentrations of nutrients nitrogen (N) and phosphorus (P), but low phytoplankton biomass and primary production. Annual primary production measured in 1980 ranged from 110 to 190 g C m 2 between Suisun Bay and South Bay (Cole and Cloern 1984), well below the primary production in other nutrient– rich estuaries such as Chesapeake Bay and Long Island sound (Cloern et al. 2014). Annual primary production in the Sacramento–San Joaquin Delta (Delta) has decreased to only 70 g C m 2 (Jassby et al. 2002), and low productivity at the food web base is a contributing factor to declining abundances of native fish and their food resources (Sommer et al. 2007). research four attributes of estuary that constrain phytoplankton light in South neap tides, fivefold multiple processes: winter–spring, rapid