While Dr. Tift, joined by UNCW Ph.D. students Anna Pearson and Alyssa Scott, UNCW Adjunct Professor Dr. Luis Huckstadt, University of California Santa Cruz Professor Dr. Dan Costa, and several researchers from the British Antarctic Survey, was studying and surveying the seals, he witnessed firsthand some major climate alarm bells going off.
“It’s a loud siren at this point”
According to the British Antarctic Survey, this past Antarctic winter was a record-breaking low for sea ice. They report that ice the size of Greenland broke off the continent. According to Tift, when these massive chunks of white ice start peeling off and move out to the dark ocean it starts to melt really fast.
“Unfortunately, when we were down there, we saw some really disturbing things. We experienced temperatures as high as 10 degrees Celsius, which is close to 50 degrees Fahrenheit in the middle of winter, in Antarctica [...] In terms of red flags, I would say it's more of a loud siren at this point,” Tift said.
He added that the captains and mates of the R/V Laurence M. Gould icebreaker, who have been going down there for 30-plus years, said they've never seen conditions this bad in their entire careers.
“They were able to travel further south, which is where it should be colder and a lot more ice, than they've ever been able to do in the past,” Tift said.
As for how this will impact the Cape Fear region, Tift said that large tidal floods are already starting to affect low-lying streets in the area, and scientists can already measure increasing sea level rise along the coast.
How melting ice impacts crabeaters
The name, crabeater, is a misnomer. Tift said about 90% of their diet is based on krill, which are tiny crustaceans that look like shrimp. The relationship between the krill and the crabeater can signal if climate change is affecting these animals.
The research team’s hypothesis is that as global warming starts to affect the ice conditions in Antarctica, the animals will move southward towards the South Pole. And so if their food is moving in this direction, the team anticipates the crabeaters to follow suit.
But traveling southward, where there’s likely more ice, could be problematic for the seals.
“Because it's just like having to take a longer trip to the grocery store. Basically, they’re spending more energy to go get the food and come back,” Tift said.
Tift said for the past two years, it’s been difficult to find the seals. Their initial goal was to work with 20 seals in both 2022 and 2023, but they only could tag and follow five the first Antarctic winter, and nine this past one.
“That's mainly due to the fact that these animals rely on hauling out of the water on these small ice floes. And these ice floes are just not there anymore. [...] Now, when you're down in Antarctica when we were in the middle of winter, there's little to no ice, so it's very scary,” Tift said.
And without those ice floes even present, Tift said the crabeaters don't have the habitat to take a break or nap, or give birth and nurse their pups.
As to why Tift and his team picked the crabeaters to study the effects of climate change, “We know that there are several millions of these animals, not only do they play a big role in the Antarctic ecosystem, but they also play a role in the entire world marine environment.” He added, that they, “also live in an area of Antarctica, the Western Peninsula, which is experiencing some of the fastest rates of warming on the planet.”
Tift and his team will compare the health measurements they collect from the seals from the last couple of years' worth of data with that from 20 years ago when the warming effect wasn't near as dramatic.
The researchers hope to have some of these results out in the fall, and are planning to publish the study’s conclusions about the following: Is the prey of crabeater seals shifting from 20 or more years ago? Is the diving strategy of crabeater seals shifting from the same time period? How do the oxygen stores in blood and muscle of crabeater seals compare to other marine and terrestrial mammals? How does the body condition (an indicator of overall health) of crabeater seals compare to other marine mammals?
The general public can follow the seals Tift and his team tagged over the past two Antarctic winters. The 2022 batch were given names from the Marvel Universe; in 2023 seals were named after fruit. You can follow the seals — including Black Panther, The Hulk, Clementine, Apple, and Kiwi — on an interactive map.
And, as of now, NSF doesn’t have more funding for them to return for the subsequent Antarctic winter, but after Tift and his team publish their results, there's the potential that they might be able to team up with other groups that have the available funding to continue working with these animals.
Sources
- UNCW researchers travel to Antarctica to study impacts of climate change and more, May 2022
- Antarctic sea ice reaches an early winter record low in June 2023, NOAA
- The mystery of the missing Antarctic sea ice, British Antarctic Survey
- Dr. Tift’s UNCW Comparative Physiology Laboratory (the link to his publications is here)
