Estuary News

September 2020

Science-in-Short ~ Podcast

Conversations with scientists actively doing research in the San Francisco Estuary. 

Drift, Drop or Floc? Tailing Sediment as it Moves Through Marsh Margins

This June two USGS scientists will be trying to get as close as they can to the edge of the South Bay’s Whale’s Tail Marsh to lay out their tools: tiles, filter paper, current profilers, and other sediment accretion measuring instruments. Estuary Reporter Ariel Rubissow Okamoto interviews reseachers Jessie Lacy and Karen Thorne about what they’re looking for at the marsh edge, and how it may help us answer burning questions about the future of the region’s wetlands. Is there enough sediment in the system to help them keep pace with sea level rise by buildng up their elevations naturally, or do humans need to sprinkle some sediment love around? What exactly does happen when sediment arrives on the marsh surface? What micro-changes in elevation, vegetation, and resuspension occur with tides, waves, and seasonal shifts? Lacy and Thorne have it covered. 

About Jessie Lacy

lacy in field

Jessie Lacy is a physical oceanographer in the Pacific Coastal and Marine Science Center of the US Geological Survey. She conducts research in hydrodynamics and sediment transport in estuaries and coastal waters, including San Francisco Bay, the Sacramento-San Joaquin Delta, Puget Sound, and Monterey Bay. Her research interests include sediment dynamics in estuarine shallows; hydrodynamic controls on sediment delivery to marshes; interaction between aquatic vegetation and hydrodynamics; and the role of the physical environment in defining habitat function in aquatic systems. Jessie worked for eight years in water quality regulation for the State of California before earning her PhD in Civil and Environmental Engineering from Stanford University.

About Karen Thorne

Karen Thorne is a Principal Investigator with the USGS Western Ecological Research Center, where her research focus is in climate change impacts to ecosystems. In particular, her work has included assessing sea-level rise and storms impacts to nearshore ecosystems, wetland ecology and wildife. She received her Ph.D. and MS from the University of California, Davis.


The Whales Tail Marsh study described in the podcast is a critical piece of the Regional Monitoring Program’s new Sediment Modeling and Monitoring Strategy. Read the latest on regional sediment science and monitoring in Okamoto’s recent article Sediment Paparazzi.

Sediment for Survival, SFEI Report Spring 2021

Listen to other Science-in-Short Podcasts

Uncut-Long Version of Beagle’s Interview by reporter John Hart

Predation in Wetlands with David Ayers

Remote Sensing for Invasive Weeds with Shruti Khanna

bicycle in mud rick lewis
Bicycle aptly named Free Spirit enjoys a final mud bath in the Emeryville flats. Photo: Rick Lewis

SCIENCE IN SHORT is co-produced by Estuary News and Maven’s Notebook, with support from the Delta Stewardship Council. Music courtesy Joel Kreisberg & Art Swisklocki. Production by Adriana Pera.

Co-published here on Maven’s Notebook.

In an effort to make science more conversational, these podcasts include thoughts and opinions on the part of scientists that are occasionally personal or informal. As such, these podcasts do not reflect the opinions or goals of their employers, institutions, or funders. 

Back to rest of issue

Receive ESTUARY News for FREE

About the author

Ariel Rubissow Okamoto is both today’s editor-in-chief and the founding editor of ESTUARY magazine (1992-2001). She enjoys writing in-depth, silo-crossing stories about water, restoration, and science. She’s a co-author of a Natural History of San Francisco Bay (UC Press 2011), frequent contributor of climate change stories to Bay Nature magazine, and occasional essayist for publications like the San Francisco Chronicle (see her Portfolio here). In other lives, she has been a vintner, soccer mom, and waitress. She lives in San Francisco close to the Bay with her architect husband Paul Okamoto.

Related Posts

subisdence on 4 delta islands map

Asked to suggest an appropriate future for four Delta islands owned by the Metropolitan Water District, it’s difficult not to want the moon.

Why not richer rice fields, more wetlands, better boat launches, extended trails, even eco-tourism? ? A new survey for the Delta Islands Adaptation Project, funded by a Prop 1 Watershed Restoration Grant, wants the public’s opinion on the importance of 10 possible land-use objectives leading to the selection of one...
chart by Hutton

An examination of 50 years of records reveals an apparent seasonal bias in estimates of freshwater flow from the Delta to the San Francisco Estuary.

The seasonal bias suggests flows were overestimated during the summer months and underestimated during the winter. Estimates of Delta outflow use a measurement called net Delta outflow index (NDOI), which is determined by taking the amount of Delta inflow, from sources such as the Calaveras, Sacramento, and San Joaquin rivers,...
diagram of fish net trawl

Fish monitoring surveys in the San Francisco Estuary net different numbers of different fish species depending upon when and how they sample.

According to a new study published in San Francisco Estuary and Watershed Science, even surveys that target the same part of the water column can come up with significantly different catches. The study’s authors analyzed decades worth of data from the California Department of Fish and Wildlife (CDFW) Fall Midwater...