Pelagic Organism Decline
The Interagency Ecological Program (IEP), a consortium of nine state and federal agencies, has been monitoring aquatic organisms and water quality in the San Francisco estuary for decades. Since late 2004, scientific and public attention has focused on the unexpected decline of several pelagic (open-water) fishes (delta smelt, longfin smelt, juvenile striped bass, and threadfin shad) in the freshwater portion of the estuary known as the Delta. This decline has collectively become known as the Pelagic Organism Decline (POD). In 2005, the IEP formed a multi-agency POD Management Team tasked with designing and managing a comprehensive study to evaluate the causes of the decline and to synthesize and report the results. The causes under investigation include stock-recruitment effects, a decline in habitat quality; increased mortality rates; and reduced food availability due to invasive species.
IEP POD Final Study Reports
2010
- POD 3-D Particle Tracking Modeling Study: Particle Tracking Model Testing and Applications Report (Gross et al.)
- Acute and Chronic Invertebrate and Fish Toxicity Testing in the Sacramento-San Joaquin Delta, 2008-2010 (Werner et al.), Appendix
- Effect of Ammonium and Wastewater Effluent on Riverine Phytoplankton in the Sacramento River, CA (Parker et al.)
- Effects of Microcystis aeruginosa in Threadfin Shad (Dorosoma petenense) (Teh et al.)
- Acute Toxicity of SRWTP Effluent to Delta Smelt and Surrogate Species (Werner et al.)
2009
- Acute Toxicity of Ammonia/um and Wastewater Treatment Effluent-Associated Contaminants on Delta Smelt – 2009. (Werner et al.)
- The Role of Contaminants, within the Context of Multiple Stressors, in the Collapse of the Striped Bass Population in the San Francisco Estuary and its Watershed (Ostrach et al.)
2008
- POD 3-D Particle Tracking Modeling Study: San Francisco Bay-Delta UnTRIM Model Calibration Report (MacWilliams et al)
- Delta Smelt: Environmental Forcing and Growth-Selective Mortality in 2005 (Bennett et al.)
- 2007 Histological Evaluation and Viral Survey of Juvenile Longfin Smelt and Threadfin Shad (Foott and Stone)
- 2006-2007 Acute and Chronic Invertebrate and Fish Toxicity Testing in the Sacramento-San Joaquin Delta (Werner et al.), Appendix
- Temperature trends at several sites in the upper San Francisco Estuary (Jassby)
2007
- Biomarkers and the Pelagic Organism Decline (Anderson et al.), Appendix
- Histopathological Evaluation of Starvation and/or Toxic Effects on Pelagic Fishes (Teh)
2006
2005
- 2005 Fish Condition and Health Indices (Gartz)
- Summary of Delta Hydrology Data Water Years 1985 – 2004 (Simi and Ruhl)
- Pyrethroid Insecticides White Paper (Oros and Werner)
- Aquatic Herbicides White Paper (Siemering and Hayworth)
- 2005 Acute and Chronic Invertebrate and Fish Toxicity Testing in the Sacramento-San Joaquin Delta (Werner et al.)
