Physiological Tolerances of Fishes of the Sacramento-San Joaquin Delta, California
Many fish resident to California's Sacramento-San Joaquin Delta (SSJD) have experienced precipitous declines in abundance over the last century (Bennett and Moyle 1996; Moyle 2002; Brown and Moyle 2005). Water management, and the subsequent development of dams, canals, and water pumping facilities, coupled with global climate change, have, in part, functioned in altering the physical habitat and chemical composition of the water (Ligon et al. 1995; Arthur et al. 1996; Brown 2000; Brown and Ford 2002). Climate change and a continued reliance on dams and reservoirs in the central valley of California will likely equivocate to further changes in water velocities, temperature, salinity, and dissolved oxygen levels (Young and Cech 1996). Similarly, increased agricultural, domestic, and industrial development has resulted in increased waste water and, subsequently, elevated concentrations of chemicals including trace metals, salt, sulfate, and nitrate (Nichols et al. 1986; Kratzer and Shelton 1998; Brown 2000). Changes in water quality and physical habitat have coincided with considerable population declines in most native fishes and alterations in species composition that have favored the expansion of non-native organisms (Jassby et al. 2002; Moyle 2002; Brown and Moyle 2005). Therefore, an absolute understanding of how fish respond to changes in their environment is necessary when restoring habitat to support native fish, to predict future SSJD species assemblages, likely outcomes of important native and non-native species, and the potential for invasion (Brown and May 2006). We are proposing to review and summarize the temperature dependent physiological tolerances and effects on metabolism of fish resident to the SSJD to water quality parameters likely to be impacted by water management facilities and global climate change.
Need and Benefit
Reclamation and the Science and Technology Office have made investigating the potential effects of global climate change on Reclamation facilities and impacted waterways a priority. A thorough review of the effects of temperature on the physiological tolerances and preferences of fishes of the SSJD will provide both Reclamation and non-Reclamation managers and scientists a single source when developing project and species management plans, working on threatened and endangered species consultation efforts, or when considering effects of current or future Reclamation projects on the fishery. Our monograph will not only minimize time (and cost) associated with a thorough species review when completing such projects, but we will also continue to display Reclamation's efforts to maintain ahead of the curve when considering effects of global climate change on aquatic ecosystems.
The following documents were not reviewed. Statements made in these documents are those of the authors. The findings have not been verified.
Physiological Tolerances of Fishes of the Sacramento-San Joaquin Delta, California (final, PDF,
By Zak Sutphin
Report completed on February 20, 2014