Garza, Laura, Alyssa DeVincentis, Romina Diaz-Gomez, Hervé Guillon, Noelle Kathleen Kathleen Patterson, Francine van der Brandeler, Arthur Koehl, et al. 2019. “Mapping Water Resources Research in Latin America and the Caribbean”. AGU Fall Meeting 2019.
Publications by Year: 2019
2019
Goharian, Erfan. 2019. “Looking to the Past and Planning for the Future: Stormwater Systems”. In 2019 National Watershed & Stormwater Conference.
Hammock, Bruce G. (2024) 2019. “Hydrodynamic Modeling Coupled with Long-term Field Data Provide Evidence for Suppression of Phytoplankton by Invasive Clams and Freshwater Exports in the San Francisco Estuary”. Environmental Management 63 (6): 703-17. https://doi.org/10.1007/s00267-019-01159-6.
The San Francisco Estuary (California, USA) had abundant pelagic fish in the late 1960s, but has few pelagic fish today. A primary cause for this decline in fish is thought to be a trophic cascade, triggered by declining phytoplankton. Here, we describe the changes in pelagic community structure of the San Francisco Estuary. Then, we examine whether changes in hydrodynamics due to freshwater exports, which increased exponentially beginning in 1967, in addition to the 1986 invasion by the clam Potamocorbula amurensis, explain the phytoplankton loss. Hydrodynamic variables were reconstructed back to 1956 using statistical models fit to, and cross-validated against, output from a hydrodynamic model. Then, we regressed mean summer/fall chlorophyll a—-the season with the largest phytoplankton decline—-against the reconstructed hydrodynamic variables and the presence/absence of P. amurensis for 1969—2014. The regression model, which explained 78% of the interannual variation in chlorophyll a, was then used to quantify the influence of P. amurensis and exports on chlorophyll a. Based on monitoring data, chlorophyll a declined 22-fold from 1969—2014, zooplankton declined 32-fold from 1972—2014, and pelagic fish declined 92-fold from 1968—2014. Averaged over 1990—2014, the chlorophyll a model ascribed an 88% decline in chlorophyll a to P. amurensis, a 74% decline to exports (at minimum), and a 97% decline to the combined influence of P. amurensis and exports (at minimum). Thus, the decline in pelagic productivity in the San Francisco Estuary has occurred largely due to the combined impacts of the P. amurensis invasion and increased freshwater exports.
Gailey, R., E. Goharian, S. Maples, and G.~E. Fogg. (2024) 2019. “‘Conditions for Accomplishing Groundwater Recharge With Flood Flows: Indications from Study of Two Groundwater Sub-Basins in California’”. AGU Fall Meeting Abstracts.
Khatami, Farboud, and Erfan Goharian. 2019. “Renewable Myths and Non-Renewable Realities about Energy Portfolio Management”. AGU Fall Meeting 2019.
Hammock, Bruce G, Samuel P Moose, Samuel Sandoval Solis, Erfan Goharian, and Swee J Teh. 2019. “Hydrodynamic modeling coupled with long-term field data provide evidence for suppression of phytoplankton by invasive clams and freshwater exports in the San Francisco Estuary”. Environmental Management 63 (6): 703-17.
Fogg, Graham, Erfan Goharian, Robert Gailey, Stephen Maples, and Samuel Sandoval Solis. 2019. “Water Security, Drought and Climate Change: A California Perspective”. Earth and Space Science Open Archive ESSOAr.