Field Notes: A Field Guide to Field Work – Island Edition

So, you want to work as a field biologist on an island? As a first step, read this essential what-to-bring list and lesson plan created by Claire Nasr, a self-proclaimed nomadic marine mammal ecologist who specializes in island ecosystems.

Islands moving clockwise: St. George Island (Alaska, USA), Corsica (France), Southeast Farallon Island (San Francisco County, USA), and Maui (Hawaii, USA)


Cold Weather Islands:


Fisherman’s Bay on the Southeast Farallon Island (left). The Farallons (30 miles west of San Francisco) are home to thousands of breeding seals, sea lions, and seabirds, including the Northern Elephant Seal (right).

While working on the Southeast Farallon Island (SEFI) and St. George Island in the Bering Sea, I had the privilege to work as a research technician studying “pinniped population dynamics.” We aimed to understand long-term population trends of marine mammals according to current oceanic conditions1 and predict future events which might affect these populations2. On SEFI, northern elephant seals (Mirounga angustirostris) are perfect candidates for this type of research because they aren’t very sensitive to human presence, allowing researchers to approach individuals with minimal disturbance3. Our team deployed hundreds of flipper tags into elephant seal pups and adults. These tags are only about 1.5 inches long, and an adult male elephant seal can be 14 feet long and weigh up to 5,000 pounds—that is a tiny tag! Tagging adults can be difficult, so it is best accomplished while the animal is sleeping. Two researchers silently approach the back end of a sleeping seal, one person delicately spreading the webbing of the seal while the other slides in the tagging shears with a loaded tag. With a carefully coordinated seal-tagging team, the tag is deployed through a quick blast of the tagging shears. This process has been conducted by researchers for decades, and yes, typically awakens the sleeping seal, but is very similar to getting an ear pierced – it’s over quickly, and only creates temporary disturbance. In my experience, the seal falls back asleep within 30 seconds of the event, seemingly unaware of what even occurred. This flipper tag has a unique number for each animal, doesn’t impair its survivorship, and is a vital tool when conducting population-based research with pinnipeds because it lasts the lifetime of the animal.

 Tagging shears (left) and a perfectly-placed tag on an adult male elephant seal. The numbers on the tag help researchers monitor long term population trends.

Want to know what’s even more challenging to tag? A 30-day old elephant seal pup (affectionately named “weaners” because they are recently weaned from milk from their lactating mothers). The hardest part of tagging a weaner is that they exhibit a very frustrating behavior: they rarely sleep. Because of this, tagging a weaner typically involves brief (>1 min) restraint by a highly-trained biologist. If you think that a weaner is weak, terrified, and dreadfully helpless, you’d be unbelievably incorrect. Even at one month old, these seals are powerful, weigh up to 300 pounds, can move quickly, incredibly strong, and wield four sharp canine teeth. These little guys are incredibly brave, and they have a secret weapon that can deter even the most weathered field biologist: poop, poop and more poop. This is the reason why the most important field item is clothes that can be destroyed!

Recently weaned elephant seal pups (“weaners”) on the Farallon Islands

On Saint George Island (Alaska), Northern fur seals (Callorhinus ursinus) aren’t much different than elephant seals. Fur seals, however, are a bit more refined; instead of protesting their contribution to science through excrement, they exhibit defiance through biting…a LOT (see field item #3). Northern fur seals can be quite aggressive, and the pups have amazing tenacity and stubbornness. After a day of weaner wrangling or fur seal tagging, I guarantee that your clothes will be completely riddled with bite holes, and soiled in sweat, tears, and… I’ll let you guess the other thing… all the feces. Because remote islands are, well, remote, luxurious amenities like a shower are very limited. And if you plan to work on a remote pinniped-covered island for several months, know that you will eventually get intimately accustomed with the smell.


Fur Seals have up to 250,000 hairs per square inch on their body and were commercially hunted in the late 1800s for their dense fur.
Bonus tip: Take photos! Pinnipeds choose to haul out at some beautiful locations, such as Island of St. George, Alaska (Photo credit: Rebekah Leverty).

Warm Weather Islands:


As a marine naturalist working in Maui, Hawaii, my key role was ensuring passenger and environmental safety while interpreting marine science and advocating for ocean stewardship.  Working underwater amongst green sea turtles, vibrant fish, humpback whales, dolphins, coral reefs and endless sea grass beds is a humbling experience but a physically demanding one. When I worked on a large vessel in Maui, passengers would often remind me that I was “living the dream” and “working in paradise.” This was absolutely true, and I felt gratitude every day. However, the demands of free-diving multiple times a day (for science), running up to five daily boat trips, and working up to 75 hours a week is demanding on the body. Each trip’s success was completely contingent on my ability to dive very deep to tie up the 85-foot boat, lifeguard and monitor the safety of up to 129 passengers, work hundreds of feet of heavy line, participate in daily boat maintenance, and constantly clean up after passengers’ regurgitation events that landed on the deck instead of the ocean.

Working as an interpreter in Maui, I taught natural history concepts to thousands of coral reef tourists each week.


In Corsica, I worked on a research project investigating fish substrate preference, which was essentially asking a fish: “What’s your favorite kind of rock and seaweed to hang out on?” Another term for this kind of research is “habitat selection,” and it can be done at many scales and in any type of environment. Of course, when you’re studying fish habitat selection, that research occurs 100% underwater. When conducting research  underwater, taking care of your body is essential for a successful field mission. If you’re new to self-care, start with the easy stuff: protect your skin and drink water. As you gain experience, you’ll learn how to concoct home remedies for ear infections, potions for sunburns, antidotes for punctures from sea urchin spines, and homeopathic relief for seasickness. Don’t forget to enjoy your journey advancing through the wild experience of warm water field research!

Bonus tip: If seasickness takes over, go to the stern (back of the boat), and don’t aim into the wind. You’d be surprised how easy it is to overlook this key detail when you’re losing lunch.

Island ecosystems are sensitive to disturbance given their small areas and abundance of endemic species that have not co-evolved with mainland predators5,6. As such, oceanic islands rank as a high priority in our global biodiversity conservation efforts5,7,8. Whether in a cold or warm environment, island-based field research is remote, intense, and truly inspiring and is not for the faint of heart. I have missed birthdays, weddings, and countless holidays, but the revolutionary marine wildlife research on islands leaves me wanting more every single time. With these pro-tip checklists, great field team partners, and a passion for nature and science, you are well on your way to becoming an expert-island field technician and ocean advocate!


Claire Nasr earned her bachelor’s degree in marine biology from UC Santa Cruz in 2012. Her work has focused on marine vertebrate ecology primarily on islands, including elephant seal and humpback whale bioacoustics, northern fur seal demography, and most recently, marine wildlife spatiotemporal disturbance research. Claire is also dedicated to providing inclusive marine science education programs for K -12 students. Note that all activities described with marine mammals is done under strict marine mammal permit guidelines.

[1] Robinson, P. W. et al (2012). Foraging behavior and success of a mesopelagic predator in the northeast Pacific Ocean: insights from a data-rich species, the northern elephant seal. PloS one, 7, e36728.

[2] DeLong, R. L. et al. (1991). Impact of the 1982–1983 El Niño on the northern fur seal population at San Miguel Island, California. Pinnipeds and El Niño. Springer, Berlin, Heidelberg, 75-83.

[3] Le Boeuf, B. J. et al. (Eds) (1994). Elephant seals: population ecology, behavior, and physiology. University of California Press

[4] Downs, C. A. et al. (2015). Toxicological effects of the sunscreen UV filter, Oxybenzone (Benzophenone-3), on coral planulae and cultured primary cells and its environmental contamination in Hawaii and the U.S. Virgin Islands. Arch Environmental Contaminant Toxicology.

[5] Kier, G. et al. (2009). A Global Assessment of Endemism and Species Richness across Island and Mainland Regions. Proceedings of the National Academy of Sciences, 106, 9322–9327.

[6] Courchamp, F. et al. (2003). Mammal Invaders on Islands: Impact, Control and Control Impact. Biological Reviews, 78, 347–83.

[7] Pearson, R. G. et al. (2003). Predicting the Impacts of Climate Change on the Distribution of Species: Are Bioclimate Envelope Models Useful? Global Ecology and Biogeography, 12, 361–371.

[8] Hester, M. et al. (2013). Año Nuevo State Park Seabird Conservation and Habitat Restoration: Report 2013. (Unpublished Report). Ano Nuevo State Park, CA: Oikonos-Ecosystem Knowledge, 244–253.

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