California DDT+ Research Needs Assessment

Updated January 13, 2023 
Media Contact: Leah Shore / / (213)-740-1960


In response to the critical gaps in our knowledge about the nature, extent, fate, and impacts of deep ocean DDT+ pollution, the University of Southern California (USC) and California Sea Grant Programs, with funding from the National Sea Grant Program, conducted A Deep Ocean California DDT+ Research Needs Assessment for the Southern California Bight in 2022 to generate a comprehensive list of DDT+ research needs, as well as context on what research is most critically needed to investigate DDT+ impacts on California coastal living resources and the communities who utilize them. Sea Grant aims for this report to provide a framework for a deep ocean DDT+ research agenda to inform timely future. 

Report and StoryMap
  • View the StoryMap of our assessment here.
  • Download the report here

Listening Sessions

USC Sea Grant and California Sea Grant hosted community listening sessions to provide feedback on the draft Sea Grant report: A Deep Ocean DDT+ Research Needs Assessment for the Southern California Bight. This report presents a framework for a deep ocean DDT research agenda to inform timely future California DDT+ research investments, based on input from the Sea Grant July 2022 California DDT+ Research Needs Workshop (more information on this workshop is provided below).  

California DDT+ Research Needs Workshop Overview 

A primary source of input for this Assessment, alongside literature review and community listening sessions, was Sea Grant’s California DDT+ Research Needs Workshop(July 18-19, 2022) that convened diverse communities managing, studying, or directly affected by deep ocean DDT+ disposal in the Southern California Bight. 

Thank you to the over 75 registrants from across academia, NGOs, and regulators at the state and regional level who attended our widely successful and informative workshop. The event was featured in California Ocean Protection Council Executive Director Mark Gold's online blog, AllWet. Read the article here.

This two-day interactive workshop aimed to synthesize California stakeholders’ perspectives on those critical research needs emerging from the recent discovery of the extensive scope of dumpsites of DDT and associated chemicals (DDT+) in the deep ocean waters of the San Pedro Basin. The workshop discussion will feed into the development of a California Stakeholder DDT+ Research Needs Assessment, further supported by a broadly administered stakeholder survey and synthesis of existing DDT+ assessment reports. 

The workshop supported four broad objectives:

  • Objective 1: Convene an inclusive, collaborative discussion among Sea Grant, academic scientists, and relevant California stakeholders;
  • Objective 2: Share high-level context of the history of DDT+ contamination in Southern California and its implications for human and environmental health;
  • Objective 3: Synthesize those DDT+ impacts of greatest concern to diverse stakeholders, building on the groundwork of previous scientific assessments of California DDT+ research needs; 
  • Objective 4: Provide continued opportunities for stakeholder engagement in the development of the Needs Assessment Report.

Workshop Recordings:

Presentations from the 2-day workshop were recorded and are available to view. To watch the presentations, click on the links below:

  • Day 1: To watch the Introduction and panel presentations from this day, click here.
  • Day 2: To watch the introduction and keynote speaker from this day, click here.

Resource Documents:

Updating and Reviewing Research on Continuing Ecological Effects of Deepwater Ocean Dumping of DDT Wastes into the Southern California Bight (Chartrand et al, 2022)

 Workshop Agenda



This workshop is jointly organized by California Sea Grant and University of Southern California Sea Grant, and funded by the National Sea Grant Office.


California Sea Grant:                                                                   University of Southern California Sea Grant:

Lian Guo, Research Coordinator,                         Amalia Almada, Science, Research & Policy Specialist,
Theresa Talley, Extension Director, Coastal Specialist                     Phyllis Grifman, Executive Director
Shauna Oh, Director                                                                       Linda Duguay, Director
                                                                                                      Charlotte Stevenson, Science Writer 

We would like to acknowledge the critical contributions of our Advisory Committee in the development of this assessment:

  • Lihini Aluwihare, Professor of Marine Chemistry and Geochemistry, Scripps Institution of Oceanography
  • Allan Chartrand, Principal Environmental Scientist, Chartrand Environmental LLC
  • Gabrielle Crowe, Tribal Council Leader/Environmental Educator, Gabrielino-Shoshone Nation/Ballona Wetlands Land Trust
  • Michael Quill, Marine Programs Director, Los Angeles Waterkeeper
  • Dave Valentine, Professor of Earth Science & Biology, University of California, Santa Barbara
  • Steve Weisberg, Executive Director, Southern California Coastal Water Research Project (SCCWRP)


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