Sailing Scholars

It all started one bright October day in the fall of 2022 when Tammy Russell (then a PhD student at Scripps) participated in a research cruise off the coast of California under the CalCOFI (California Cooperative Oceanic Fisheries Investigations) program. Struck by the rich biodiversity, from whales to seabirds, over the so-called Santa Lucia Escarpment located just outside the proposed boundaries of a new national marine sanctuary near Point Conception and Morro Bay, Russell put together a UC Ship Funds proposal to lead an expedition to study the escarpment.

Established in 1995, the UC Ship Funds program, supported by UC San Diego, Scripps Institution of Oceanography and forward-thinking philanthropists, enables graduate and undergraduate students (as well as early career researchers like postdoctoral scientists), to pursue independent research at sea. Every year, the program funds about 55 days at sea aboard Scripps’ different research vessels on cruises that can range from one-day trips off San Diego to month-long expeditions in international waters. The program offers the opportunity for students to practice writing research proposals and gain experience doing science at sea.

Awarded a week of ship time aboard Scripps research vessel Robert Gordon Sproul, and after COVID forced us to postpone the cruise by a few months, a team of graduate students set out for the Santa Lucia Escarpment in spring 2024. Unfortunately, strong winds and swells made sampling very difficult aboard R/V Robert Gordon Sproul and we were forced to return home without much of the data we had hoped for. 

But what do you do when Mother Nature throws a wrench in your scientific plans? You dry out your foul weather gear and try again. Thus, in fall 2024 Grace Cawley, a PhD candidate in the lab of marine biologist Moira Décima, led an even larger team of interdisciplinary graduate students on another UC Ship Funds proposal for a follow-up expedition to the escarpment. This time, the group was composed of Scripps students working on everything from phytoplankton to zooplankton, seabirds, acoustics, marine mammals, internal waves physics, and even included a couple of UC San Diego students in visual arts and ethnography. 

Fast forward to February 2025 and 15 graduate students and now postdoctoral researcher Tammy Russell stepped aboard R/V Sally Ride for round two of Santa Lucia Escarpment Science. Bigger boat, even bigger scientific goals. 

Since Russell’s first student proposal was written, NOAA had decided in November 2024 to designate the Chumash Heritage National Marine Sanctuary. Thanks in large part to Russell’s advocacy, the final sanctuary boundaries were redrawn to now include parts of the escarpment. This added even more impetus to our goal of collecting data on the ecological conditions and biodiversity in the region to be able to offer information about the state of the sanctuary to the Chumash Peoples and NOAA, who co-manage it. 

The plan was to conduct rigorous sampling at 12 stations across the escarpment. At each sampling location, we started with a CTD (conductivity, temperature and depth) cast using the shipboard apparatus known as a rosette. We took water samples at multiple different depths to measure various seawater properties such as nitrate and chlorophyll concentration. We also collected samples of environmental DNA (eDNA) to help identify what marine species might be present. The eDNA method is based on being able to pick out traces of DNA left behind in the water from animals such as fish and whales when they pass through without having to physically see or capture them.

The CTD cast was followed by three different types of trawl nets for sampling zooplankton: the Manta net (for sampling the surface layer), the Bongo net (for quantitative analysis of the upper ocean), and the Isaacs-Kidd Midwater Trawl (IKMT, which targeted the deeper waters in search of deep-sea squid). All types of nets brought back an abundance of organisms, from long-toothed deep-sea fishes to vibrant red crustaceans to multiple kinds of squid and Velella velella. 

With science happening 24/7, it didn’t matter if we reached the station mid-afternoon or 2 a.m. The shift in charge was out on deck hauling nets overboard or in the lab filtering water samples and identifying all the critters being brought back on board. During daylight hours, the dedicated marine mammal and seabird observers witnessed a captivating diversity of birds, whales, dolphins and large fishes thriving in the productive ecosystem.

One part of the escarpment in particular provided a rarely seen display of what appeared to be humpback whale courting behavior between pairs of cetaceans, which earned the region the nickname “the Humpback Motel.” The last few days of the cruise were dedicated to investigating the physics underlying the region. Using the CTD rosette in “yo-yo” mode (continuously profiling up and down through the water column in a fixed location), the physical oceanographers onboard collected ocean current velocity data that will hopefully help us tie together the physical processes with the biological samples to understand how they connect.

For some of the students onboard, this was their very first experience of going to sea while others marked their 200-days-at-sea milestones. As anyone with a couple of research trips under their belts will tell you, however, each cruise is unique. During this particular one, the team got to practice both teamwork and creativity navigating everything from severe seasickness to rapidly adapting the sampling plan due to unplanned restrictions issued by the U.S. Navy. 

Nonetheless, spirits stayed high the entire time, whether we were doing facemasks and playing charades in the lab between net trawls, or trying to fight off numbness in our fingers while stitching together a torn trawl net on the back deck as the sun slowly rose above the horizon. The incredible team is what made this cruise a success and for all of us this was a truly unique learning experience getting to be part of such an interdisciplinary and all-student team. And although R/V Sally Ride is back in port, the story of the Santa Lucia Escarpment goes on as we now have an abundance of data to analyze, documentary films to make and papers and thesis chapters to write to try to solve some of the mysteries of this unique marine sanctuary. 

The EAT-SLE 2025 science team consisted of Grace Cawley, Tammy Russell, Kerstin Bergentz, Dante Capone, Victoria Boatwright, Freya Hammar, Joe Riley, Katrina Johnson, Kristina Fleetwood, Luisa Watkins, Lin Hou, Lindsey Kim, Michaela Alksne, Charlene Ruiz, Clarissa Chevalier and Yurim Lee. 

We wish to thank the UC Ship Funds for their support in making both Santa Lucia Escarpment cruises possible, as well as the crews and captains aboard R/V Robert Gordon Sproul and R/V Sally Ride for getting us safely out there and back to do our science.

Kerstin Bergentz is a fifth-year PhD student with the Multiscale Ocean Dynamics lab and Lagrangian Drifter Lab at Scripps. She researches air-sea interactions, upper ocean dynamics and various types of waves.