News & Special Events!

  • 2025 IEP Annual Workshop March 4-6, 2025 at the CNRA Headquarters Building
    • Workshop Registration opens February 3, 2025! Subscribe to the workshop listserv to receive updates.
    • IEP is hosting a Scientific Presentations and Posters Training Course February 7. Registration is required.
    • Want to attend the Early Career Scientist Luncheon? Or be a volunteer? Registration is open for those as well!
    • Visit the IEP Annual Workshop web page for registration links and more information.
  • Call for IEP Newsletter Articles for Volume 44, Issue 1! Submission deadline is February 15, 2025.
  • Invasive Non-Native Golden Mussel Discovered in Sacramento - San Joaquin
    • On October 17, 2024, Golden mussels (Limnoperna fortunei) were found attached on a float near the Port of Stockton. Golden mussels are native to rivers and creeks of China and Southeast Asia. They are similar in appearance, biology, and impacts to quagga and zebra mussel, and pose a significant threat to water conveyance systems, infrastructure, and water quality. On October 31, 2024 a press release on Golden mussel detection in the California Delta was distributed by the California Department of Fish and Wildlife. This release can be shared with water managers across the state to inform them of this discovery. More information on Golden Mussels is available on the CDFW’s Invasives web page, and questions can be directed to invasives@wildlife.ca.gov.
  • Got something new to share? Contact us at iep@wildlife.ca.gov.

IEP Calendar

Check out the IEP Calendar for upcoming Project Work Team, Stakeholder Group meetings and other IEP related events!

  • January 8 Predation Project Work Team Meeting from 1:30 p.m. to 3:30 p.m.
  • January 15 Sturgeon Project Work Team Meeting from 1:00 p.m. to 4:00 p.m.
  • January 16 Estuarine Ecology Team Project Work Team Meeting 9 a.m. to 12:00 p.m.

IEP Blogs and Videos

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Featured Survey

  • Enhanced Delta Smelt Monitoring (EDSM)

The Enhanced Delta Smelt Monitoring (EDSM) program started its 2024 Phase 3 sampling program for juvenile and sub-adult Delta Smelt on July 1, 2024. In order to improve our ability to make inferences about the population, sampling effort is being focused on geographic areas where Delta Smelt are likely to be caught based on historical data. Sampling locations are generated using a generalized random-tessellation stratified (GRTS) design (Stevens 2004) with stratification and equal probability sampling. Trawling gear similar to that used in the California Department of Fish and Wildlife’s Spring Kodiak Trawl Survey is used to conduct multiple tows per site. More information regarding this survey and past reports can be found at website maintained by the U.S. Fish and Wildlife Service.

Featured Publications

  • Patterns in Anthropogenic Nitrogen and Water Quality Leading to Phytoplankton Blooms in Urban Estuaries is the title of a recent article in the Journal of Marine Science and Engineering. From the abstract by Dugdale, Parker, and Wilkerson: “For blooms to occur, NH4 must first be reduced to non-repressive levels, then NO3 uptake can occur and is accompanied by more rapid carbon (C) uptake and chlorophyll accumulation…. We apply the statistical relationship to a 40-year time series from the SFE during which there was an ecosystem-scale change in the estuarine foodweb with a drastic decline in pelagic fishes (the pelagic organism decline) and suggest that this period aligned with the lowest annual primary production and highest NH4.”
  • Paerl and 6 co-authors share a publication found in Science of the Total Environment titled Dual nitrogen and phosphorus reductions are needed for long-term mitigation of eutrophication and harmful cyanobacterial blooms in the hydrologically-variable San Francisco Bay Delta, CA. This important paper concludes the abstract by noting “… it appears that internal supplies of “legacy P” ensure P availability throughout the summer bloom season regardless of hydrologic variability, while N enrichment plays a key role in stimulating algal production and CyanoHABs under hydrologically variable conditions. Once N was added, P further stimulated biomass production in some cases, indicating potential N+P co-limitation. We conclude that under varying hydrologic conditions, long-term dual N and P input reductions are needed to control eutrophication and CyanoHAB outbreaks throughout the SFBD.”
  • Long and others have published an article detailing the use of elastomer tags in Delta Smelt. “Our results suggest that visible implant elastomer tagging is a suitable method for marking adult Delta Smelt (>50 mm fork length) for up to 165 days and can be useful for conservation monitoring efforts.” You can find their article: Evaluation of visible implant elastomer (VIE) tags for use in supplementation of an endangered fish in the North American Journal of Fisheries Management.
  • San Francisco Estuary and Watershed Science (SFEWS) has published two articles by Hartman and co-authors in a recent edition (volume 22, issue 1).
    • The first, Amazing Graze: shifts in jellyfish and clam distributions during dry years in the San Francisco Estuary discusses “ We investigated the population responses of these invasive species to dry years and their potential effects on the pelagic food web using data from the Interagency Ecological Program’s monitoring surveys. We found M. marginata rapidly moves upstream with changing salinities during dry years, though it sees its highest abundance during high-outflow years in Suisun Bay and Suisun Marsh…. M. marginata, P. amurensis also shifts upstream during droughts, but because adults cannot move immediately with a change in salinity, the population center of distribution shifts upstream the year after a dry year as a result of juvenile recruitment.”
    • In the second SFEWS article, Hartman and others from the IEP Drought Synthesis Team released (in a special issue on drought from earlier this year) Dry me a river: ecological effects of drought in the Upper San Francisco Estuary. The abstract indicates that: “ Our models showed droughts decreased Delta outflow, project exports, zooplankton in Suisun Bay, and some fish species. We also found that droughts increased water clarity, salinity, nutrients, chlorophyll in the South Delta, zooplankton in the South Delta, and water residence time.”

Featured Dataset Publications

Featured Websites