A student at sea…

By Brijonnay Madrigal (SEC Program Assistant & Graduate Student at Moss Landing Marine Labs)

Fish Communicate

Figure 1. The Velero IV (Photo credit: Ryan Fields).

Did you know that fish make sounds? They do! Some fish species, like the rockfish you eat in your fish tacos, are soniferous (sound producing). Fish produce a drumming sound by striking the gasbladder (swim bladder) and the sonic muscle together. Rockfish (Genus Sebastes spp.) are a genus that produce low frequency sounds associated with agonistic interactions and territorial defense. Due to this ability, it is proposed that rockfish may elicit an acoustic response due to increased noise produced by survey vehicles used to study rockfish populations. This concept fueled NOAA’s desire to deploy hydrophones to record survey vehicle operations in Southern California and rockfish in these areas. This acoustic work was one component of the Untrawlable Habitat Strategic Initiative (UHSI) SoCal Project, a collaborative effort between NOAA Northwest, Alaska, and Southeast Fisheries Science Centers. The goal of the 2-year project was to assess rockfish response to survey vehicles and determine the biases in studying rockfish using vehicles such as AUV’s (Autonomous Underwater Vehicles- like the one displayed at the SEC) and HOV’s (Human Operated Submersibles). Cruises were conducted in the Channel Islands in October 2016 and this last month in October 2017. Last year I was a data analyst for the project but this year, I got the opportunity to be a part of the research team onboard. I worked along scientists from the SWFSC Fisheries Ecology Division in Santa Cruz, CA and NWFSC Fishery Resource Analysis and Monitoring Division in Newport, OR. My role was to handle all operations for the 3 hydrophones we deployed along with a variety of sensors including a turbidity meter, light sensors, and accelerometers. The cruise was 2 ½ weeks long and the longest duration of time I had ever spent at sea so I was excited to get away from land for a bit and live on a ship for 18 days!

Home at Sea

Figure 2. The platforms.

The ship that would be my home for the next 2 ½ weeks was the Velero IV (Figure 1), a shipping vessel from Seattle, Washington that had been modified for this project. An extra sleeping quarters had been transferred onboard as well as a lab for the scientist that consisted of a one room cubicle with benches that they had placed on the ship using a crane. We spent the first day docked in Ventura Harbor preparing the platforms we would be deploying. The 3 platforms (Figure 2) (each named after a different Fisheries Science Center) were fitted with DIDSON imaging sonar, that produce images of the fish used to quantify species and measure fish lengths. MOUSS cameras were also placed on the platforms which took pictures every 2 seconds and are used to assess fish movement, species diversity and abundances. While the research team worked on putting together the platforms, the submersible team was hard at work preparing the DeepWorker manned submersible which would be used to deploy the platforms on the sea floor (Figure 3). We departed from Ventura, CA on October 9th and set out to sea at sunset. I was nervous at first, wondering what the conditions would be like especially since I am prone to seasickness but fortunately, almost every day was beautiful and calm in sunny Southern California.

A Typical Day

Figure 3. The submersibles.

There was no need for my phone alarm in the morning because between the loud clanking of the anchor being pulled up and the smell of bacon, we were always up by 6:30am. The Velero IV would leave Smuggler’s Cove off Santa Cruz Islands and after a short journey to our survey area would arrive at site at 7am. Our survey area was Footprint Bank, an area between Santa Cruz and Anacapa Island where 3 sites had been determined as locations to deploy the platforms. Once on site, the science team turned on all devices, placed them on the platforms and then with the help of the crew and sub team, the platforms were lowered over the side of the vessel. The sub attached a line to the platform using a metal claw that would allow the platform to be descended to the bottom (Figure 4). Once at the bottom, the sub operator would un-attach the line and we would then continue to the next site. After all 3 platforms were deployed we would leave the area and return to Smuggler’s Cove for a 3-hour period while the NOAA Shimada vessel conducted AUV flybys and seafloor mapping. At approximately 3pm we would return to Footprint Bank and the sub might conduct some flyby passes near the platforms prior to retrieving the platforms before sunset.

Amazing Marine Life

Figure 4. Deploying the Alaska platform one morning. The sub is in the water preparing to take the platform down to the bottom.

Throughout the day we would always see marine mammal. I was the only marine mammal scientist onboard so if marine mammals were sighted, the crew and research team always called me to the top deck to identify species. We saw pods of bottlenose dolphin, long-beaked common dolphin, Risso’s dolphin and an extremely active lone humpback breaching and tale slapping one day. After we headed back in and anchored in Smuggler’s Cove for the night, I would go up to the bow of the ship to see the “show”. Bioluminescence glowed green in the water and even in the middle of the night you could see sea lions chased schools of fish and track the movements underwater as their bodies glowed green…it was like Fourth of July in October! One night, as we were heading into Santa Barbara to anchor up for the night, I was looking at the water from the top deck when suddenly, I saw these green glowing torpedoes moving in the water near the bow of the vessel, spinning and crossing each other as they glided through the water. I went down to the bow to get a closer look and saw they were dolphins bow riding! The bioluminescence in the water was causing their torpedo shaped bodies to be outlined by a green glow which allowed you to see their every movement in the dark water. It was the most amazing thing I had ever seen!

Rockfish are a dominant demersal fish species in benthic ecosystems and are of recreational and commercial importance in California. The UHSI project is important as it will shed light on some important implications for ground fish research and the anthropogenic impacts on these species. I was grateful to have the opportunity to be involved in the data collection process, so I could gain a better understanding of the project and perspective on the data. Going out to sea makes all the long hours of analyzing data and staring at a computer screen worth it!

Katie Harrington

Katie Harrington

I've taken a diverse approach to my passion for biology and being out in the field. I currently focus on studying the movement and feeding ecology of Striated Caracaras in the Falkland Islands. An amazing bird! They're social, gregarious, run as much as they fly, and fill a similar ecological niche as the North American raven. Birds of prey are sentinel species of the earth’s environment, so I have a deep passion for contributing scientific knowledge that can guide conservation and management programs.

For my Master’s thesis, I collaborated with Hawk Mountain Sanctuary to develop energy budget estimates for the striated caracara using 3D acceleration loggers. Knowing caracaras’ energy needs is essential to understand their ecological role and to better assess how human-dominated landscapes might affect their survival.

In addition to my research, I also work on sailing vessels as well as in small boat ops, assisting coastal California research efforts as experienced field crew, including operating vessels, performing marine bird and mammal surveys, and photographic ID work for long-term baleen whale studies.

The biological world stuns me, and I want to share that with others. I do that through writing about local research and science-based ecological restoration. I've published in Bay Nature, for NOAA Fisheries', and in Salish Sea Currents. I obtained my BA in American Studies from Stanford University and built my foundation in biology through additional coursework at the University of Washington's Friday Harbor Laboratories and the College of Marin.


Katie defended her thesis titled "Seasonal time-energy allocation of an island-restricted Falconid, the Striated Caracara, using a low-cost, open-source inertial movement GPS logger" in 2019. You can find her thesis results in this article published in the journal Animal Biotelemetry.

Shawn Hannah

Shawn Hannah

I graduated from California Polytechnic State University, San Luis Obispo, with a B.S. in Biological Science concentrating in Marine Science and Conservation. During my undergraduate studies, I took part in research with tropical coral fish, range-size studies of temperate fish, male elephant seal population surveys and pathology of marine mammals. It was my time working at The Marine Mammal Center (TMMC) doing animal husbandry and rescue that solidified my desire to pursue work with wild marine mammals. When I began interning in the Vertebrate Ecology Lab at MLML, I had the opportunity to assist other students in a variety of projects. This included humpback whale identification, UCSC elephant seal monitoring, Risso’s dolphin vocalization and identification, as well as the Marine Mammal Stranding Network. 

Currently, I am a third year graduate student at MLML. For my thesis I am studying northern elephant seals and their natural diving physiology. This includes recording their heart rate throughout natural dives and comparing it to their dive depth, duration, and movement. This research will give us insight into how these incredible divers are capable of long duration dives and how they are managing their oxygen.

Brijonnay Madrigal

Brijonnay Madrigal

My passion lies in marine mammal acoustics and the communication and behavioral function of vocalizations. In Spring 2016, I graduated from the University of Hawai’i at Mānoa with a B.S. in Marine Biology and a B.A. in Communication. As an undergraduate, I was selected as a NOAA Ernest F. Hollings Scholarship recipient. Through this program, I completed a research internship at the NOAA Southeast Fisheries Science Center, where I determined sperm whale abundance using passive acoustic data. This experience started marine mammal acoustics pursuits. I have since been involved in field studies, volunteer opportunities and internships to study and learn various aspects of cetacean acoustics, behavior, husbandry and psychology in Hawai’i, Florida and Puerto Rico. I served as a research assistant for a project conducted in collaboration with both the U.S. Navy and the Hawai’i Institute of Marine Biology Marine Mammal Research Program, to assess dolphin presence through whistle detection at sonar detonation sites.

My research at MLML was under the direction of Dr. Alison Stimpert and Dr. Gitte McDonald. My master’s thesis focused on characterizing acoustic behavior of odontocete species and is comprised of two parts: (1) A data analysis of passive acoustic data (provided by the NOAA Alaska Fisheries Science Center) of killer whales from the Bering and Chukchi Sea, Alaska to formulate a vocal catalog of pulsed calls. (2) A passive acoustic study of free-ranging Risso's dolphin whistle and burst pulse vocal repertoires in Monterey Bay, California.


Bri defended her thesis titled "Determining ecotype presence and the call repertoire of killer whales (Orcinus orca) recorded near Point Hope, Alaska" in 2019. You can read her thesis manuscript here.

Jenni Johnson

Jenni Johnson

I graduated from San Jose State University with a B.S. in Biological Science focusing in Marine Science. During my undergraduate studies, I was an animal husbandry and rescue volunteer for the Marine Mammal Center, while interning in the Vertebrate Ecology Lab at MLML. Through my experience as a volunteer I acquired a foundational skill set for working with wild pinnipeds which enhanced my curiosity about how these animals survive in extreme environments. As an intern in the Vertebrate Ecology Lab, I had the opportunity to assist in a variety of projects. This included being a member of the Marine Mammal Stranding Network, assisting with diet analysis of California Sea Lions, and volunteering with elephant seal demographic studies at UCSC.

Currently, I am a fourth year student under the direction of Dr. Gitte McDonald. My research aims to investigate the influence of maternal foraging strategy on reproductive output in Northern elephant seals using stable isotope analysis. This project is being done in collaboration with the Costa Lab at UC Santa Cruz.

Sharon Hsu

Sharon Hsu

My love for the ocean started at a young age. I grew up playing in the tidepools and I have never lived far from the water. I received my B.S. in Ecology, Behavior, and Evolution from UC San Diego, and then spent a number of years working abroad, first as Peace Corps volunteer in the Republic of Vanuatu and later as a project coordinator for a sea turtle conservation group in Costa Rica and volunteer coordinator for various conservation projects.


Sharon defended her master's thesis titled "Using stable isotopes to determine foraging areas of leatherback sea turtles: Limitations of the stable isotope tracking technique in the Western Atlantic Ocean" in December 2019. You can read her thesis manuscript here.

Heather Barrett

Heather Barrett

My interests in ecology began at a young age as I interned with the Lawrence Hall of Science and Berkeley Botanical Garden, teaching youth biology classes. I took a more marine focus as a student at UC Santa Cruz (UCSC) where I joined the Sea Otter Research and Conservation program (SORAC), partnering with UCSC, US Geological Service, and the Monterey Bay Aquarium. After receiving my Bachelor of Science in Ecology and Evolution, I continued with SORAC and pursued a career with the California Department of Fish and Wildlife. For six years I performed field-work and developed the photography catalogue for the long-term diversity database of Northern California.

During this time I was fortunate to live and work abroad. I assisted with a variety of research programs including whale shark photo identification in Bahia de los Angeles, Mexico, and participate in Wildland Studies Program of CSU Monterey Bay throughout the country of Belize. I am thrilled to be a member of Dr. Gitte McDonald’s Vertebrate Ecology Lab at Moss Landing Marine Laboratories, and am interested in the use and development of remote monitoring systems to better understand marine vertebrate behavior and physiology. For my thesis I worked with Sea Otter Savvy to assess the energetic cost of human disturbance on the southern sea otter.

Heather defended her thesis titled "The energetic cost of anthropogenic disturbance on the Southern sea otter (Enhydra lutris nereis)" in 2019. You can read her thesis manuscript here.

Mason Cole

Mason Cole

I graduated from UC San Diego in 2010 with a degree in General Biology (physiology focus) on a pre-med track. I soon decided I liked ecology more than people biology, and set out to South America with a one-way ticket and almost no plan. 1.5 years and my full savings account later, I returned to the US via many buses, taxis, and a couple planes, and sporting a handful of conservation/biology experiences. A few outdoor education and field biology jobs led me to pursue my own career in marine biology (particularly concerning large predators), and in 2014 I began an internship in this lab.

For my Master’s thesis, I am investigating the underwater movement and foraging patterns of wild California sea lions. I am approaching this goal from two angles. First, I am working with trained sea lions at SLEWTHS (here in Moss Landing) to understand how accelerometers can be used to identify when sea lions make feeding attempts.This study will provide a method by which researchers can figure out where, in a dive, wild sea lions catch prey.Second, I am analyzing movement, energy expenditure, and foraging data from wild California sea lions at San Nicolas Island, CA. The idea here is to get high-quality instantaneous measurements of metabolic energy expenditure from movement data (acceleration, magnetic compass bearing, rotational velocity) recorded by a small animal-borne datalogger. I hope this research will improve our understanding of sea lions’ underwater movements and foraging patterns, and how these patterns relate to energy expenditure during foraging trips to sea.

Stephanie Schneider

Stephanie Schneider

My interest in ecology is broad and I enjoy working with a diversity of organisms, both terrestrial and marine. I began my Master of Science at Moss Landing Marine Laboratory in Fall 2014.  As a graduate student, my research has focused on the interrelations between the local prey community, foraging effort and the ability to produce young for Common Murre nesting at Castle Rock National Wildlife Refuge over the last decade. This island is one of the largest seabird breeding colonies in the Pacific Ocean south of Alaska and is in an area of the California Current System where seabirds have rarely been studied.

Since 2009, I have supervised all aspects of seabird research at Castle Rock and have been fortunate enough to focus on an aspect of this larger project for my thesis project. Preliminary analyses show that Castle Rock is unique relative to other breeding colonies in the California Current System; the diet of murres nesting at here differs from other locations and murre behaviors suggest it is challenging to obtain adequate food to raise young. Access to the island is prohibited while seabirds are nesting and, to make detailed observations, I rely on a unique system of remotely operated cameras that are broadcast to the mainland using wireless technologies. You can watch live video of seabirds nesting at Castle Rock 24 hours per day during the breeding season (April to August)

If you want to learn more about seabirds nesting in northern California, including Castle Rock, check out the most recent and comprehensive report ever made for this region. And for an overview of environmental conditions of the California Current System and biological impacts to plankton, fish, and top predators read the most recent State of the California Current report.

Although I have dedicated a majority of my time to Castle Rock over the last decade, I have also assisted with various wildlife projects at Humboldt State University, Humboldt Bay National Wildlife Refuge, and H.T. Harvey & Associates Ecological Consultants.


Stephanie defended her master's thesis titled "Reproductive performance, foraging effort, and diet of an apex predator, the common murre, at one of the largest nesting colonies in the California Current System" in 2018. You can read her thesis manuscript here.


A day in the life of an elephant seal biologist at Año Nuevo State Park

BEEP! BEEP! I roll over to turn off my alarm and read the clock: 4:30 a.m. Begrudgingly I arise, slip into my field clothes, and head to the kitchen to make breakfast before beginning the forty-five minute commute to Long Marine Lab (LML). As I drive north, I mentally prepare myself for the day ahead. Today our focus is assisting with the annual weanling weighing effort. Upon arrival at LML, the field crew assembles all necessary gear, electronically checks into the park, and then piles into the truck. As we cruise up Highway 1 the sky begins to lighten, gradually revealing the charming California coast while the truck buzzes with conversation.

Twenty minutes later the truck pulls into the entrance of Año Nuevo and turns right down the limited access road. The progression is slow as we carefully survey the dirt road for endangered San Francisco garter snakes.I take this opportunity to observe the magnificent landscape, hoping to catch a glimpse of deer, coyotes, bobcats, or the elusive cougar. Alas, no such luck today. Instead, I admire the soft glow of the early morning light and the captivating shades of pink and orange spilling across the sky, signaling the eminent arrival of the sun. I feel excitement start to build as we park the truck.

Grabbing the gear, we hike to the beach, maneuvering through streams, marshes, and dunes along the way. Various animal tracks crisscross over the sand, reminding me that I am merely a guest. The elephant seal calls fill my ears, and I know we are close. We emerge onto the beach as the sun makes its morning debut atop the Santa Cruz Mountains and casts light onto the awe-inspiring scene before us.

Pelicans and cormorants congregate on the western point, paling in comparison to the demanding presence of the elephant seals. Nursing females, defensive bulls, dozing juveniles, and curious weanlings cover the beaches and play in the surf. We appreciate this scene for only a moment before setting off to find our first weanling.

Scanning the beach for a good candidate, I can’t help but notice the diversity of rocks, shells, and bones that decorate the sand; untouched by human hands and I absorb the beauty. Within minutes we find a prime candidate, indicated by its unique bleach mark. We set down our gear, delegate tasks, and establish a plan emphasizing the safety of the researchers and animals is paramount then get to work.

One group begins to set up the tripod, attaching the scale and come-along winch to the tripod before anchoring its feet into the sand. Meanwhile, I am tasked with capturing the weanling. For this, a custom-made canvas bag is used to help protect the seal and the researchers as we collect our measurements. Rolling back the seam of the bag, I slowly creep toward the weanling. Suddenly aware of my presence the weanling raises its head to maintain visual contact. Using this to my advantage, I swiftly sweep the bag onto its head. Another researcher steps in and together we carefully wrestle the seal into the bag taking extra care not to harm its flippers. In the process, we expose its belly and identify thesex as male before securing the bag. With impressive coordination, three people position the tripod over the weanling while I connect the bag to the come-along winch via a metal weigh bar. I crank the winch lever slowly lifting the seal until he is completely suspended, record his mass, and then immediately lower him to the ground. Once the weigh bar is removed one pair of researchers relocates the tripod assembly while I assist my field mate collect body measurements and a fur sample. Next, we add green flipper identification tags. Two tags are inserted to indicate he has been measured and weighed. Finally, I release the weanling from the bag and estimate percent molt as he galumphs across the sand. Despite what it may seem, the process lasted only ten minutes.

Nine weanlings later, my watch reads 9:15 a.m. and it’s time to depart. On our return hike we encounter a ranger, stop momentarily, say hello, and summarize the morning. Once again, the truck is filled with chatter, this time with questions and lingering thoughts regarding our morning. Upon returning to the labs the gear is cleaned, bags are restocked, and samples are stowed. For the team, this marks the completion of our morning. However, before my morning concludes, I must enter the data. Another forty-five minutes in the car flies by as I reflect on my Año Nuevo morning and silently appreciate the opportunity to experience this wondrous place.