Much research in the Delta has focused on foodweb dynamics, stimulated by evidence that low productivity of plankton is linked to declines in several fish species including the endangered delta smelt. Pseudodiaptomus forbesi is the most abundant copepod (small crustaceans) in the Delta in summer. It is an important food source for many fishes and makes up about half of the food of delta smelt. This study focuses on the feeding, reproduction, and growth of copepods as essential foodweb support for fishes. This work investigates four diverse habitats including two open-water channels and two shallow habitats. The researchers will measure copepods' feeding rates on microscopic plants and animals, and relate feeding to their rates of growth and reproduction. Computer models will be used to estimate their movement and death rates. These results will show the sources of nutrition used for growth and reproduction of these key organisms. Results will inform how food webs respond to large scale changes in the Delta ecosystem, for example, restoration and the Sacramento wastewater treatment plant upgrade.
Assessing the success of tidal marsh restoration is a top priority for coastal managers across the US. Estuarine habitat restoration has been prioritized due to the importance of the ecosystem functions (Callaway et al. 2012) and services (Costanza et al. 2014) they provide and the threats to them by climate driven sea-level rise (hereafter SLR; Craft et al. 2009, Donnelly & Bertness 2001, Schile et al. 2014) and other stressors (Mariotti & Fagharazzi 2013). Given the importance of management for estuarine habitats to survive SLR (Kirwan & Megonigal 2013) and the importance of public responses to approve and fund restoration projects, it is critical to understand how to broadly assess the success of restoration from the perspectives of both ecological performance and public perceptions. However, the San Francisco Estuary (SF Estuary), stretching from the Lower San Francisco Bay through Suisun Marsh to the Sacramento-San Joaquin Delta, encapsulates diverse social and environmental dynamics (Moyle et al. 2014) and varying perceptions by sociodemographic group (Rudnick et al 2022). Our project is focused on the Suisun Marsh and Delta and seeks to understand these complexities by integrating social, environmental, and management perspectives.
