Students

The VEL rung in the New Year and the start of the semester with a group dinner at the Whole Enchilada in Moss Landing.

We hope you had a restful winter break and spent time with your loved ones!

Congratulations to VEL student Taylor Azizeh for advancing to candidacy!

Taylor's thesis will focus on investigating the foraging ecology of late chick-rearing emperor penguins (Aptenodytes forsteri) off Cape Crozier, West Antarctica. Specifically, Taylor will use machine learning to identify potential foraging events from biologging data. By combining foraging attempt and dive data, Taylor can estimate what potential costs and benefits of different foraging strategies might be. Ultimately, Taylor hopes that her work will offer novel information to the seabird ecology world, and that eventually, this work can be used in management strategies to better protect ice-obligate species like penguins.

Congratulations to VEL student Taylor Azizeh for becoming a National Science Foundation (NSF) Graduate Research Fellowship Program (GRFP) fellow! Her MSc thesis will focus on researching the foraging ecology of emperor penguins in the Ross Sea, Antarctica, using biologging.

Welcome to the Vertebrate Ecology Lab, Sebastian and Vicky!

Sebastian Caamaño graduated from UC Santa Cruz with a B.S. in Marine Biology. He also worked with the Pinniped Cognition and Sensory System's Lab where he got to experience working with marine mammals for the first time. Working as an intern, he got to contribute to the daily care and training of the resident seal and sea lion species. Simultaneously, he assisted in several of research projects. These opportunities ranged from hearing tests with a California Sea Lions to physiological work with two arctic seals and even developing some human trials along the way. This volunteership, led him to the Alaska SeaLife Center where he continued his behavior and physiology work with arctic seals as a Research and Animal Care Technician. Ultimately, these experiences led him to the Vertebrate Ecology Lab here in Moss Landing. Since joining, he has enjoyed working for the Marine Mammal Stranding Network and hope to continue working on the physiology of marine mammals.

Vicky Ooi completed her bachelor's degree in Marine Science and Zoology from the University of Queensland, Australia. She then entered an honors research year investigating dugongs along the coast of Southeast Queensland with Drs. Janet Lanyon and Lee McMichael. During this period, I successfully pioneered a fecal DNA extraction protocol that allowed amplification of both mitochondrial and nuclear DNA from free floating dugong feces. This development enabled single nucleotide polymorphisms (SNPs) to be amplified from dugong scats, representing a breakthrough for non-invasive population genetic studies in this species.

She relocated to the United States around mid-late 2022, completing an internship program at Hubbs SeaWorld Research Institute (Species Preservation Lab) with Karen Steinman, further acquiring laboratory skills on semen quality assessments, cryopreservation, enzyme immunoassays, and hormone analyses. Her thesis will focus on the foraging ecology of emperor penguins in Antarctica, simultaneously working part-time as a naturalist on the Sea Goddess whale-watching cruise.

Congratulations to our very own Parker Forman and Daphne Shen for recently defending their theses'.

Parker Forman

Thesis Abstract:

I described the at-sea behavior of emperor penguins (Aptenodytes forsteri) during late chick-rearing at Cape Crozier. Analyzing data from eight penguins, I investigated how intrinsic factors, including sex, size, and body condition influenced their behaviors. Penguins exhibited mean trip durations of 10.6±3.4 days, covering a daily distance of 55.7±8.0 km. Penguins predominantly performed dives within the upper 200 meters of the water column (90.7±26.5%), with a smaller proportion of dives (9.3±2.0%) reaching greater depths. Deeper dives were typically associated with shallow bathymetry. Penguins conducted an average of 1,860±681 dives with maximum depths of 455.8±32.6 m and durations of 12.9±2.4 minutes. Penguins spent 66.4±14.8% and 43.9±4.4% of their time at sea resting and diving.

Penguins with similar behaviors were categorized into groups: Group I foraged near the continent and traveled to the Ross Bank, and Group II predominantly foraged near the continent. I found significant differences in foraging behaviors between the groups and sexes. The composition of these groups was influenced by sex. Group I mostly comprised males, while Group II were females and one unknown sex. Females displayed higher dive frequencies per day (Females (F):186±17, Males (M):151±4), shallower maximum depths (F: 432.2±29.4 m, M: 476.8±12.8 m), and shorter durations (F: 3.2±0.7, M: 3.9±0.3). Possible explanations for the observed differences between male and female penguins include energetic requirements, prey preference, physical characteristics, and niche differentiation, which can shape their distinct foraging behaviors.

Furthermore, results from this study indicate that penguin behaviors were also influenced by the physical characteristics and condition of their bodies. This finding suggests that there may be an optimal body condition for achieving greater diving depths. Penguins with intermediate body conditions may possess a more efficient physiological adaptation for sustained deep diving, enabling them to access resources inaccessible to individuals with lower or higher body compositions.

This study advances our understanding of late-chick-rearing penguins and the influence of intrinsic factors on their behavior. The findings indicate that emperor penguins exhibit divergent strategies influenced by sex and physical condition, leading to variations in dive behavior and bathymetry use. These sex-based disparities in penguin behavior highlight distinct ecological roles for each sex within the species. These findings provide a novel description that underscores the remarkable adaptations of emperor penguins in successfully navigating dynamic environments at Cape Crozier.

Daphne Shen

Thesis Abstract

Understanding how marine mammals respond to and recover from acoustic stressors is crucial if underwater noise increases. The use of an animal-borne biologger that combines a speaker with a motion sensor allows for the collection of whole-dive and fine-scale data over repeated exposures under identical experimental parameters. This study determined whether northern elephant seals (Mirounga angustirostris), a model for deep-diving marine mammals, exhibited a stereotypical behavioral response when exposed to killer whale whistles, an acoustic stressor. I examined changes in dive characteristics, measured duration of altered response, and observed behavior in response to repeated exposures. When exposed to the playback on ascent, the elephant seals performed an escape response consisting of a dive inversion during which they increased activity and displayed more variation in swimming direction. However, the seals returned to baseline diving behavior immediately after the exposure dives, suggesting they recover quickly from disturbance. After repeated exposures, the seals continued to perform dive inversions but reduced the extent of their responses over time. Even though northern elephant seals appear to recover quickly from this acoustic stressor, the initial strong behavioral response still causes an increase in energy expenditure that could be detrimental over time, especially if they are continuously faced with disturbances. Integrating behavioral responses with physiological measurements will help us fully comprehend how these animals change their diving behavior in response to increased sounds in the ocean.

As of Fall 2022 these students in the Vertebrate Ecology Lab have received approval for their Theses Proposals and are now moving into Master's Candidacy

Jack Barkowski

Jack’s thesis work will investigate patterns in humpback whale vocalizations along the U.S. West Coast. Jack will look at the spatiotemporal variation in humpback whale song activity over a 3 year span within the Olympic Coast National Marine Sanctuary, Monterey Bay National Marine Sanctuary, and the Channel Islands National Marine Sanctuary . He will also report the presence and acoustic characteristics of 5 specific non-song calls that have been documented in humpback whale populations around the world, suggesting that these 5 call types play an important role in social interaction. Jack hopes his work will reveal spatiotemporal differences in peak song activity that will allow for more effective management decisions aimed at reducing entanglement risk in fishing gear and ship strikes from large vessels, the two leading causes of anthropogenic-caused mortality for large whales.

Kali Prescott

Kali's thesis work will be focusing on exploring how Computational Fluid Dynamics can be used to estimate drag incurred by biologgers and other externally attached devices.  She will be examining Northern Elephant Seal, Mirounga angustirostris, as a model species using 3D scans collected during the seal's haul out periods at Año Nuevo State Reserve. These scans will be used to build 3D models of the seals along with 3D models of the biologgers generated using Computer Assisted Design Software (CAD). Using a fluid dynamics program originally designed by Engineers, Kali will simulate drag and drag coefficient by placing the tagged seals models into a computer generated flow through chamber. These models will be used to identify what factors associated with biologger attachment (size, location, and number of loggers) will most impact the incurred drag. These proxies for drag will then be compared to foraging, dive, and reproductive data collected from animals tagged in real life to determine if there are any measurable impacts.

Many beach goers love to watch coastal animals resting, playing, and swimming along the shoreline, including my typical study species, the southern sea otter. However, some species are much harder to find and require extensive efforts to see them, even for the experts! During the months of August and September I worked with a small team of scientists from NOAA and the affiliated organizations Upwell Turtles and Moss Landing Marine Laboratory to survey the Oregon and Washington coastline and locate, capture, and gather valuable information on the endangered leatherback sea turtle.

As a part of the aerial team, I assist with locating these five- to six-foot, 800- to 1400-pound leatherback turtles, but it’s not as easy as it may seem!

My role as an aerial observer involves scouring the seas for any signs of turtle habitat, food, and other associated species - plus on our very best days the turtles themselves! The Western Pacific leatherback sea turtle population has declined by approximately 80 percent since the 1980’s^1,2. Leatherbacks face challenges all throughout their lives. Although they are largely protected at their primary nesting beaches, they still face threats at secondary nesting beaches, where adults are occasionally still harvested, and eggs poached. Upon leaving their nesting grounds, juvenile and adult leatherback turtles face a maze of fisheries as they pass through the Exclusive Economic Zones (EEZs) of many fishing nations and international waters while traversing the entire Pacific Ocean to reach the western coastline of North America. Once in North American coastal waters, adult leatherbacks spend the summer and fall months feeding on blooms of jellyfish that annually occur with upwelling events of cold, nutrient-rich water being drawn to the ocean surface¹. How these leatherbacks select and re-locate these patches year after year is still unknown, and part of what we hope to investigate with our surveys. But fear not, we have figured out some clues to help us in our search.

On “fly-days” our lead researchers Scott Benson and Dr. Karin Forney have undergone intense weather monitoring and decided we face good wind and cloud conditions that should provide calm, white-cap-free waters. In our ideal weather days, the waters are so calm that we can see the airplane’s reflection on the water from 650 feet in the air! Once we get the go-ahead, we pile into our cars, head to the airport to meet our NOAA pilots, and prepare our recording equipment before strapping in and taking off!

On our first few flights, we hoped to get a coarse understanding of the environment along the Oregon and Washington coastlines and to identify areas where we might have the best luck turtle-spotting. Over the course one week, we spent 28 flight hours flying transect lines that extended from Newport, Oregon to just south of La Push, WA. With these long flight days, we collected data on water conditions, jellyfish blooms, and marine species presence within 25-30 miles of the coast. Our initial transects were spaced every four miles of latitude, which narrowed to a more fine-scaled 1-mile spacing as we focused in on the main target area. Non-turtle species data we collect not only assists with our project but can also be used in other studies such as harbor porpoise population surveys.

But how did we get this information? We stuck our faces (almost) out of the plane of course! But not how you might think...

For these surveys we are flying a specially modified Twin Otter plane owned by NOAA that has a large “bubble window” on either side just behind the pilots and an additional belly window in the back of the plane. These windows combined allow our observers an almost 180-degree view of the water below! While surveying, each observer spends approximately 45 minutes sticking their entire head and shoulders into the windows and calling out every species of animal they see. Then when you finally start to feel a kink in your neck and think you may never make it out of the window, you rotate! My personal favorite spot in the plane is the belly window, where you lay in the back of the plane, stick your head into the small window, and watch the water, algae, and animals as you fly by. If you’re lucky enough to be in the belly on a perfect day, you can even spot your own reflection hundreds of feet below!

Although these views sound glamorous, much of our time is spent looking through sun glare, counting tens to hundreds of animals (sometimes in the span of a few minutes), and making sure you don’t lose focus waiting to find the elusive turtle hidden amongst the algae and ocean sunfish (Mola molas).

Over the last several years of leatherback research, a trend has appeared that leatherbacks are often found in association with dense aggregations of large Mola mola, or ‘molas’, as we call them for short. Large molas are typically four to eight feet in diameter or longer and feed on the same food as leatherback sea turtles: blooms of jellyfish species including brown sea nettles (Chrysaora fuscescens) and moon jellies (Aurelia spp). While flying over the water, when we hit an area of ‘Mola mayhem’ it’s a period of excitement, focus, and a little bit of insanity – especially for the data recorder. I had the eye-opening experience of data recording through my first section of ‘Mola mayhem’ during this field season, where every observer was calling out mola sizes and numbers every second and my entire job was to record them on our digital data log as fast (and accurately) as possible. My fingers were flying so fast I even knocked a key off the keyboard! Don’t worry though, I replaced it at the end of the mayhem.

To get an idea of the mayhem picture this, you’re standing in the middle of an auction house where three different auctioneers are calling out their bids at the same time and your job is to write down everything each auctioneer is saying simultaneously and correctly. Mayhem is the only description. However, it’s extremely important data to collect to really narrow down where our turtle habitat may be, as this helps us find the few leatherbacks that are still making it through the maze of fisheries to our coastlines each year. The proof is in the results.

At the end of our third survey day, with only an hour of fuel left, our team was flying through Mola mayhem calling out large molas left, right, and center when the belly observer calmly called out “turtle” and all chatter stopped for what felt like the longest second. In this time, our pilots and data recorder marked the coordinates as fast as possible, and everyone instantly went on high alert. This was our chance. The pilots circled back, once more flying over the area while every observer was trying to look past the glare of the sun sitting low on the horizon. The pilot started a count down, “You should see it in three…two… one…” and to our amazement the turtle popped out of the glare. The entire crew erupted with excitement and started calling out directions, “turtle at your nine-o’clock, just under the wing!” We managed to circle it for approximately 15 minutes, relocating it between shallow dives and getting a good look to confirm there was no tail (which means it was not an adult male). It was a large, round female and our first aerial sighting in the Pacific Northwest since 2011!

It was the perfect ending to what had been my longest day of flying so far, and a sense of hope for the rest of our survey efforts. Now that we know where to find ‘turtle water’, we have our zone of Mola mayhem, and we know there’s still turtles out there, we hope we can find more turtles for Stage 2: boat capture and tagging. Hopefully I’ll have more updates for you all at the end of the field season, until then I’ll be one pair of the eyes in the sky!

References

1. Benson SR, Eguchi T, Foley DG, Forney KA, Bailey H, Hitipeuw C, Samber BP, Tapilatu RF, Rei V, Ramohia P, Pita J, Dutton PH. 2011. Large-scale movements and high-use areas of western Pacific leatherback turtles, Dermochelys coriacea. Ecosphere. 2(7):art84. doi:10.1890/ES11-00053.
2. Benson SR, Forney KA, Moore JE, LaCasella EL, Harvey JT, Carretta J V. A long-term decline in the abundance of endangered leatherback turtles, Dermochelys coriacea, at a foraging ground in the California Current Ecosystem. Glob Ecol Conserv. 2020;24:e01371.
3. Tapilatu RF, Dutton PH, Tiwari M, Wibbels T, Ferdinandus H V, Iwanggin WG, et al. Long‐term decline of the western Pacific leatherback, Dermochelys coriacea: a globally important sea turtle population. Ecosphere. 2013;4:1–15.