Chesapeake Biological Laboratory

Navigating new waters

Loss of summer ice raises questions about changing Arctic

The public needs to understand things that are happening now. It’s not like you can change something in 10 years and it’s going to go back. It’s not going to go back, not in our lifetime or our children’s.

Jackie Grebmeier
Researcher Professor, Chesapeake Biological Laboratory

Jackie Grebmeier and Lee Cooper have worked in Arctic waters every summer for more than three decades.

There have been surprising sights and memorable moments, from up-close walrus encounters to the one summer the scientists were able to bring their daughter along. Their biggest surprise, however, was what they didn’t see this past summer.

“It was totally ice-free there,” Grebmeier said, freshly returned from three cruises in Arctic waters spanning July through mid-September. “I didn’t see any polar bears this year. Normally you see those around the ice. It was dramatic to me.”

Even sea ice melts back in the Arctic during the summer months, but the researchers from the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory have always seen some on at least one of their cruises. For their last trip Aug. 26 to Sept. 15, they were on board an icebreaker, USCGC Healy, that cruised through the Bering Strait and into the Arctic Ocean proper without having to break any ice.

Dramatic as it was, the missing ice was just another in a series of changes Grebmeier and Cooper have observed and are working to document after years of navigating and studying the same waters. Some changes were already apparent in the 1990s when they put out their first paper detailing a decade of research results.

They have had a front-row seat to a changing climate and have in turn been sharing their experiences and discoveries through research papers, community presentations, and providing leadership in addressing international scientific challenges in the Arctic.

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In 2013, they helped establish the Distributed Biological Observatory, an international collaboration—originally involving the United States, Canada, Japan, Russia, China, and Korea—that aims to share select measurements from a coordinated monitoring effort in the Pacific Arctic that will advance understanding of Arctic waters and the animals that live there.

Additionally, Grebmeier serves on the executive committee for the Pacific Arctic Group and was the former vice president and U.S. delegate of the International Arctic Science Committee (IASC), which is a non-government organization that helps to coordinate international scientific research in the Arctic. Cooper is now a U.S. delegate for IASC and chairs its Marine Working Group.

“I do feel we have a responsibility to society and the people that pay for our research to report back that things are changing and it does look serious, and we need to pitch in and do something, both personally and as a society, to slow down what appears to me to be irreversible climate change,” Cooper said.

During their summer cruises, Grebmeier and Cooper collect a variety of samples: water, mud, and zooplankton and phytoplankton (the tiny animals and plants at the base of the food web) living in the water.

Everything they collect can tell them about life below the surface. For example, electronic measurements are made of temperature and salinity in the water and samples are brought back or measured onboard the ship to determine the concentrations of nutrients or chlorophyll.

Aboard the Healy, they combed through several pounds of mud and creatures, such as brittle stars and sea cucumbers, scooped from the bottom. This simple survey, often done in the same locations each year, reveals what lives in the biological rich sediments and facilitates answering questions about the state of organisms amid changing ocean conditions. Also during that trip, Grebmeier incubated sediments that were cored in long tubes from the ocean bottom to see how fast life in that sediment metabolizes oxygen and exchanges nutrients with water on the sea floor.

The costs of handling storm and wave damage and coastal erosion are big issues. Sea ice is undeniably disappearing and there are costs associated with that.

Lee Cooper
Researcher Professor, Chesapeake Biological Laboratory


During the Healy cruise, the scientists had three weeks to collect their data. On board the 429-foot ice breaker, weather was sometimes rough, with winds whipping to 35-40 knots (40-46 miles per hour) at near freezing temperatures, and they worked in split shifts of either noon to midnight or midnight to noon.

The earlier cruises were on smaller vessels—the Sir Wilfrid Laurier, a 272-foot Canadian Coast Guard vessel, and the Norseman II, a privately owned 119-foot crabbing ship that has been refitted for science —and they work on deck regardless of the hour.

View the seafloor from their 2016 research cruise.
View the seafloor from their 2017 research cruise.

“On the Laurier, we have a limited complement of people, so we work around the clock, and sleep when we can,” Cooper said.

“If lunch happens when you’re sampling, you don’t stop sampling,” Grebmeier added. “You put in an order that says save my lunch and you collect everything.”

They didn’t even stop sampling when a barking walrus came up to inspect their equipment, she said, but it did make the work more exciting.

“You do what you have to do,” Grebmeier said. “It’s quite intensive. You’re running on your energy and fumes through those three weeks and then you come back and crash for a bit and then you start your normal work day.”

Changes on the Arctic

After collecting and analyzing years of samples, they have observed some long-term declines in populations of some of the animals that live in the mud on the ocean floor in the Bering Strait region. Such bottom dwellers as clams and the shrimp-like amphipods are key prey species for walruses, bearded seals, diving sea ducks, and gray whales, but also might not be getting as much food due to the faster currents—another change the scientists noted in their research.

“We’ve also seen some of the animals that we’re used to seeing at one point, move north a certain number of miles,” Cooper said.

Animals count on the ice. It is a resting spot for diving ducks, while walruses use it as a platform for riding, resting, and nursing calves. Walruses also use it to access the Chukchi shelf to feed.

With the disappearance of ice in the offshore feeding areas, “now what they’re doing is spending a lot of time swimming between the shore and where they have to feed,” Grebmeier said.

“They’re spending more energy to get the same bang for their buck, basically.”

When sea ice melts earlier and returns later, it’s thinner. Losing layers of ice built over years gives scientists another level of questions about the future of the Arctic in a warming world and any effects beyond the ecosystem.

Cooper said scientists are drawing connections between loss of sea ice and changes in the jet stream. Without ice, there is less of a gradient between the temperatures in the Polar region versus more temperate regions and that could lead to increased variability in weather patterns.

“Cold air isn’t bottled up north,” he said.

There is also potential for more storms and rougher waves, which pose a potentially costly threat to populated Arctic coastlines.

“The costs of handling storm and wave damage and coastal erosion are big issues,” Cooper said. “Sea ice is undeniably disappearing and there are costs associated with that.”

As summers without ice become more common, the open Arctic waters could attract more ships of people keen on exploring a new frontier, Grebmeier said. That has ramifications ranging from invasive species to overfishing, and increases potential for ship strikes on marine animals.

The changes they have seen call for action.

“We need to decide where are the places we can put our energy to understand the system and then society, through its policies, will have to make some hard decisions that I don’t think people want to make right now,” Grebmeier said. “The public needs to understand things that are happening now. It’s not like you can change something in 10 years and it’s going to go back. It’s not going to go back, not in our lifetime or our children’s.”