Why Scientists Love Palmyra

An Interview with Jenn Caselle

"Palmyra is so much more healthy than other reefs. It has an intact marine ecosystem where the entire food web is still in place."

Palmyra Atoll, a Nature Conservancy preserve since 2001, recently celebrated its fifth anniversary as a Marine National Monument. Scientists say the expansion of the protected area to 13 million acres is helping establish Palmyra as a world-class research site. The goal: to discover solutions that will reverse the decline in reefs worldwide. 

“Because Palmyra is free from human pressures like overfishing and pollution, we believe lessons learned there about how reefs survive can help us save them in Hawai‘i and beyond,” said Dr. Eric Conklin, the Conservancy's Hawai‘i director of marine science.  “The Conservancy is dedicated to working with our partners to unlock the secrets contained in this natural reef ecosystem.”

Dr. Jenn Caselle agrees. She’s a marine ecologist with the University of California at Santa Barbara and a member of the Palmyra Atoll Research Consortium. Below, she provides a glimpse of what it’s like to be a researcher at Palmyra.

How long have you been doing research in Palmyra?

I first went to Palmyra in 2001 right after The Nature Conservancy purchased the atoll. As a marine ecologist, I started out studying Palmyra’s amazing bonefish population, for insights on what they eat, where they move, how often they reproduce, and how they survive catch and release. Studying this important recreationally fished species in an environment with little to no fishing pressure can tell us a lot about how to keep bonefish at healthy levels in other places.

What research have you enjoyed the most at Palmyra?

For the past nine years, we have been tagging sharks, jacks and other top predators to follow their movements, because this is what makes Palmyra unique in the world. It’s a predator-dominated ocean, where big fish rule the reefs.

How does Palmyra compare to the other places you’ve done research?

Every time I get into the water at Palmyra I have to take a minute or two to reset my thinking. It is just an overwhelmingly special place. You see sharks all around you right away, and this just doesn’t happen in other places. Palmyra is so much more healthy than other reefs. It has an intact marine ecosystem where the entire food web is still in place.

Palmyra is uninhabited and in the middle of the Pacific Ocean faraway from people, so why is it such an important research station?

Many scientists have come to the conclusion that studying degraded reefs will not give us the answers we need to restore them. We’ve got to study healthy reefs like those at Palmyra to understand how coral reefs used to be and how they should be in the future. That’s the only way we are going to restore reefs worldwide.

What are the key threats to Palmyra’s marine life?

The major threat is a global threat, and that’s climate change. We aren’t sure how healthy coral reefs will respond to increasing water temperatures, and we want to find out if they are more resilient than degraded reefs to that sort of threat.

What lessons does Palmyra offer for other reefs, coasts and islands?

First, it is important to make people aware that there are still really healthy ecosystems out there so that people are encouraged to protect the natural world in their own backyards. Second, we can’t effectively restore coral reefs if we don’t know what a healthy one looks like. Palmyra provides a baseline for how a healthy reef functions, so we can set the right conservation and restoration goals for other reefs that have been damaged by pollution and overfishing.

You have been conducting research at Palmyra for a long time now. Describe one of your best days on the atoll. 

We had an interesting, and accidental, breakthrough one year while gathering data on bonefish movements. One evening we were beyond Dudley Island, about halfway out the big channel, fly fishing for bonefish so we could put monitoring transmitters on them. While there, we witnessed hundreds of bonefish amassing in the shallows, and we believe this was a very rare sighting of bonefish reproduction. This is a very mysterious and wary fish, but there they were, the “ghosts of the flats,” hundreds of bonefish swimming around our feet. Bonefish spawning aggregations have never been scientifically documented, and we know very little about how long they last or when they occur. But we seem to have stumbled upon one at Palmyra. It was magical to witness it. 

Dr. Caselle’s research at Palmyra Atoll is done in collaboration with Dr. Alan Friedlander (University of Hawai‘i), Dr. Chris Lowe (California State University), and Dr. Yannis Papastamatiou (Hawai‘i Institute of Marine Biology) under a partnership of the Palmyra Atoll Research Consortium, The Nature Conservancy and the U.S. Fish and Wildlife Service.