IEP News

Breaking News!

  • NEW! The 2024 IEP Workshop is coming soon so mark your calendars! The in-person workshop will be held April 23-25, 2024 at the California Natural Resources Agency Headquarters building in the aduitorium. A Data Training Course will occur the week prior, April 18. Registration for the workshop opens March 15. Visit the IEP Annual Workshop web page for more information. No registration is required to view the posters on the 2nd floor of the building but registration will be required for the following.
    • In-person registration (EventBrite) for attending the live presentations in the auditorium.
    • Remote registration (Zoom) for attending remotely to watch the presentations.
    • Data Training Course registration (MS Forms) for attending the remote training on April 18.
  • The Sacramento-San Joaquin Green and White Sturgeon: A Comprehensive Review 2023 (pdf) paper by CA Sea Grant Fellow (2023) Sam Pyros is now available on the IEP Sturgeon Project Work Team page.
  • The project leads for the Summer Townet Survey have published the Summer Townet fish catch and environmental data in the Environmental Data Initiative (EDI) Data Repository. This should also soon be discoverable in DataONE and Google Dataset Search. The citation for the data is as follows:

Featured Survey

  • Smelt Larva Survey:
    • When the weather turns cold and stormy it can mean it’s spawning season for many of our native Estuary fishes. The Smelt Larva Survey is out on the water during the wet winter keeping tabs on the reproductive activities of our endangered and threatened species of smelts. The Smelt Larva Survey began in 2009 and provides near real-time distribution data for Longfin Smelt larvae in the Delta, Suisun Bay, and Suisun Marsh. These data are used by agency managers to assess vulnerability of Longfin Smelt larvae to entrainment in south Delta export pumps. The gear is highly efficient at retaining small larvae, and the project also collects data on other larval fish species.

Featured Publications

  • The effects of long-term hatchery-based management of the Central Valley steelhead is the subject of an important new article published in The Canadian Journal of Fisheries and Aquatic Sciences. In their abstract, Huber and co-authors describe how: “The California Central Valley steelhead (Oncorhynchus mykiss) has declined precipitously since Euro-American colonization and has been listed as threatened under the United States Endangered Species Act since 1998. Hatchery-origin fish now dominate the population, and hatchery management is a key listing factor. However, scant release metric information is available. We compiled a time series of O. mykiss hatchery release data for all four Central Valley hatcheries releasing O. mykiss between 1948 and 2017. The biocomplexity of released fish has declined since the early 1980s.”
  • In a breakthrough captive culture endeavor, the North American Journal of Aquaculture reports that Tien-Chieh Hung and colleagues have successfully reared reproducing Longfin Smelt in captivity for the first time. This development creates new opportunities for conservation and research work for this imperiled native San Francisco Estuary species. The authors write: “The study represents a major breakthrough in the cultivation of Longfin Smelt, showing that it is possible to complete their life cycle under controlled conditions. It has provided valuable understanding of the maturation and breeding processes in these fish, with an emphasis on the influence of salinity. These outcomes are crucial for conservation strategies, offering the potential to help establish a refuge population and laying the groundwork for further research aimed at refining captive breeding methods for this species.”
  • Critical information characterizing the transition of Green Sturgeon from freshwater to brackish is the subject of a research article from Poytress, Polansky, and Gruber in the Journal of Applied Ichthyology. Transmitter-equipped age-0 green sturgeon were tracked in the Sacramento River to assess distribution, movement speed, and downstream migration for over 300 kilometers. The article asserts: “These data provide information that was previously unknown about the life history of the southern distinct population segment of the North American green sturgeon and can be utilized to assist with water resource management and recovery of this threatened fish species.”
  • Rogers and 8 co-authors published a very readable article titled: Evaluating top-down, bottom-up, and environmental drivers of pelagic food web dynamics along an estuarine gradient in the well-regarded journal Ecology. From the article abstract: “Identification of the key biotic and abiotic drivers within food webs is important for understanding species abundance changes in ecosystems, particularly across ecotones where there may be strong variation in interaction strengths. Using structural equation models (SEMs) and four decades of integrated data from the San Francisco Estuary, we investigated the relative effects of top-down, bottom-up, and environmental drivers on multiple trophic levels of the pelagic food web along an estuarine salinity gradient and at both annual and monthly temporal resolutions. We found that interactions varied across the estuarine gradient and that the detectability of different interactions depended on timescale.”
  • Temperature tolerance of laboratory-reared Longfin Smelt is the subject of an article by Yanagitsuru and others in a recent volume of Conservation Physiology. The article describes the use of a cardiac assay for evaluating larval fish performance when exposed to increasing temperatures and suggests upper limits to incubation temperatures for this species.
     

Featured Dataset Publications

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

  • March 21 Estuarine Ecology PWT Meeting 9:00 a.m. to 12:00 p.m.

Other Events or News

  • San Francisco Estuary Partnership (SFEP) launches Estuary Youth Council
    • In 2023, the SFEP kicked off a new youth-centered program called the Estuary Youth Council. This is a pilot leadership development program developed in collaboration with Mycelium Youth Network, Nuestra Casa, and Restore the Delta. The Estuary Youth Council will give young people, especially youth from underserved communities, opportunities to advise environmental managers with youth-centered perspectives, priorities, and concerns in the restoration and adaptation of the San Franciso Estuary as well as offer professonal development.
  • Got something new to share? Contact us at iep@wildlife.ca.gov.

Frontiers for Young Minds: Where the river meets the ocean - Stories from San Francisco Estuary

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IEP Playlist on YouTube - collection of videos from IEP activities (e.g. Annual Workshop, Monitoring & Synthesis, DS Model Workshop)

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