On International Seal Day, Expert Calls for Expanding Southern Ocean Protection

Michelle LaRue’s high-tech research focuses on Antarctic crabeater seals

On International Seal Day, Expert Calls for Expanding Southern Ocean Protection
International Seal Day
Michelle LaRue, with a crabeater seal in Antarctica.
Jesse Hiatt

The Weddell Sea, located in the Southern Ocean off Antarctica, is one of Earth’s last remaining wildernesses and is known for its exceptional biodiversity, which includes emperor and Adélie penguins and multiple species of whales and seals. But a changing climate and expanding commercial fishing in the Southern Ocean are threatening the region’s ecosystem and the thousands of marine species living there.

On this year’s International Seal Day, March 22, we caught up with Michelle LaRue by email, who holds a doctorate in conservation biology and studies populations of Southern Ocean species using high-resolution satellite imagery. With funding from The Pew Charitable Trusts’ campaign on protecting the Southern Ocean, she called on citizen scientists to help her analyze crabeater seal populations across the remote Weddell Sea by reviewing satellite images and sharing their opinions on whether they think they spot seals.

Results from this cutting-edge research may be taken into consideration in October when delegations from 24 countries and the European Union gather for the annual meeting of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) to decide if the Weddell Sea will be designated as a marine protected area (MPA). This designation would safeguard critical foraging and breeding grounds for crabeater seals and other species that thrive in this unique area. It would also serve as a major contribution toward the International Union for Conservation of Nature’s target of safeguarding at least 30 percent of the world’s oceans by 2030.

Q: What makes the Southern Ocean—and more specifically the Weddell Sea—special to you?

A: The Southern Ocean is special for all kinds of reasons: It’s super-cold and deep, and has therefore been home to many fish species that over millions of years have been isolated and adapted to these cold waters. The Southern Ocean is also beautifully dynamic, with sea ice distribution changing on a daily basis, moving in and out with the summer and winter—it’s beautiful to watch on time-lapse. And the Weddell Sea is this expansive, rugged, and harsh place. The pack ice there often hangs on through the summer and is home to many different animals, from krill to whales and crabeater seals.

Q: What environmental changes have you seen in the Weddell Sea? What are the biggest threats to this ecosystem, and what should be done to address them?

A: The Weddell Sea, due to the heavy pack ice, is very difficult to access and is therefore still relatively undisturbed. Without giving away unpublished data, I can say that I have seen massive swings in some of the wildlife populations there—something I would not have expected. I think the biggest threat to the Weddell Sea is probably altering the food web due to fishing. The pack ice remains heavy through the summer, and so I would expect it to be a rare refuge for wildlife as the climate changes. But that can only be the case if the food web is not irreparably altered.

Q: What benefits do you expect high-tech methods—such as the one you’re using—to have on research and conservation efforts?

A: I see high-resolution remote sensing as another tool for long-term monitoring of the environment and the animals within it. This imagery allows us access to some of the most remote places on the planet—places where we desperately need a better picture about what’s going on. Setting up standardized methods for using this technology is one of my goals, in collaboration with my colleagues, and I think we have a good set of practices in place to study long-term population trends.

Q: You invite people from around the world to take part in your research through online citizen scientist platforms. Why is this engagement important to you?

A: Engagement with the public is critical because I want people to see what I see. Citizen science, in my view, helps democratize science, and I hope it ushers in a fresh understanding and enthusiasm of how science works. Plus, by looking at images and voting on what you see, you’re helping us cover more ground—or, ice, really—than we could do on our own. So in our case, citizen science not only enhances interest in science itself and the ecology of the Southern Ocean, but it increases our efficiency in getting research done.

Q: This October, CCAMLR member nations will meet to consider proposals to establish marine protected areas in the Southern Ocean, including in the Weddell Sea. What impact do you hope your research will have on this meeting and on Southern Ocean conservation?

A: I sincerely hope our research can add detail about the life history of an important krill predator: the crabeater seal. Our study is focusing on a time in the seals’ lives when they are hauled out on the pack ice raising their young. To my knowledge, no one has been able to do this before, to see such high-resolution detail of the sea ice in the Weddell Sea during the springtime. If we can get a better handle on the distribution, density, and habitat requirements for crabeater seals during this important part of their life cycle, I hope this will add not only to basic knowledge of the species but to the conservation efforts needed to ensure the ecosystem functions like it should, in perpetuity.

Q: International communities are calling for the protection of 30 percent of the world’s oceans by 2030. What role do large-scale networks of MPAs in the Southern Ocean play in that quest?

A: I think large-scale networks of MPAs in the Southern Ocean would represent humanity’s ability to successfully set aside some of the most unique and still untouched pieces of ocean before they are spoiled. As a species, humans are often reactive rather than proactive, working to recover biodiversity and ecosystem function until after it’s been altered, sometimes beyond repair. I think if CCAMLR can set aside the Southern Ocean as soon as possible, those leaders will have demonstrated that they have the foresight to protect large sections of our coldest ocean before it got to be too late.