Dr. Michael Tift of UNCW, a recent recipient of the university’s Rising Research Excellence Award, and doctorate. Student Anna Pearson was stationed in Patagonia, Chile, for two and a half weeks to self-quarantine before embarking on her month-and-a-half trip to Antarctica on the Nathaniel B. Palmer, a large research vessel icebreaker.
Their research grant of more than half a million dollars over three years is made possible by the National Science Foundation.
Tift and Pearson are joined by Dr. Luis Huckstadt, assistant professor at UNCW and senior lecturer at the University of Exeter, Dr. Dan Costa of the University of California, Santa Cruz, UCSC Ph.D. student Arina Favilla and UNCW student Zaahir Santhanam.
The polar location is important for their research on the impacts of climate change.
“It is one of the regions that has experienced one of the fastest rates of warming in the world. And that’s why we’re going to the West Antarctic Peninsula,” Pearson said.
They study these impacts through a sentinel species, animals that detect risks to humans, warning in advance of danger – in this case, the danger of warming seas.
“We know that crabeater seals have a fairly exclusive diet of krill. And so that makes it a really great species to understand what’s happening to the whole ecosystem in terms of climate change, and where krill species can move in response to certain climate warming, as well as where predators could move in response to changes in krill,” Pearson said.
Dr. Tift said these sentinel species are those that can be studied “to learn more about the multiple levels of health within other populations and/or the environment. Since these are top predators, their overall health can tell researchers how their environment as a whole is.If the environment has changed so much that it is affecting small organisms and conditions that impact crabeater seals’ food (e.g., the krill), then they might see it in the health of the crabeater seals.
Tift said their name was a bit of a misnomer – scientists believe it was a mistranslation.
“So crabeater seals, they don’t really eat crab, they eat krill, which is a crustacean. So they’re like a little shrimp basically,” Tift said.
And there are millions of these seals, according to Tift, “Most people on Earth don’t know about crabeater seals because they really only exist in Antarctica. Few people are lucky enough to see them or even know them.
Tift and Pearson build their work on the research of Dr. Costa and Dr. Huckstadt. They studied the health of crabeater seals about 15 years ago.
“And so our job is to go down and try to repeat some of these measurements to see if there are any differences. We will also do health measurements in animals trying to understand body condition, diet, just mass differences, things like that,” Tift said.
While in Antarctica, researchers hope to tag seals to understand their migration patterns. They will only have about five months of data because the tag falls off when the animals molt.
“It will also transmit the location so we can sort of see where the animals are going and how much time they spend traveling, looking for food, things like that,” Tift said.
It is Tift’s hypothesis that crabeater seal populations change location in Antarctica.
“The idea is that as the western Arctic gets warmer, it potentially causes a lot of animals to want to move south, where it will be colder, a little closer to the South Pole,” said Tift.
According to Tift, it could also mean they have to search deeper – or they have to search longer.
Tift’s research on deep-diving mammals and CO
Tift and his team will also study carbon monoxide (CO) levels in these joints. His area of expertise is how high levels of gas help protect these deep-diving marine mammals – and how that ability has implications for human health.
“Recent research has shown that small and low doses of carbon monoxide have quite powerful protective effects for cells and tissues. And the most promising protective effect is anti-inflammatory or anti-apoptosis,” Tift said.
This part of the research focuses on the ability of marine mammals to regulate blood flow, limiting it during deep dives.
If a cell is injured, the body can “mark” it to be destroyed, so the body can make new cells. This is called apoptosis and it’s usually a natural and controlled part of growth and development, but too much apoptosis or cell death could lead to problems for organic tissues.
This can occur in so-called ischemia-reperfusion events: ischemia is the restriction of blood flow and reperfusion restores that blood flow. Apoptosis can be triggered during ischemia and continue during reperfusion, causing inflammation.
Enter CO, which can help reduce this inflammation, which translates into potential treatments for those having a stroke, heart attack, or organ transplant — all situations where blood flow is reduced or stopped, then restarted.
“And so carbon monoxide, in many cases, reduces the number of organ transplant rejections. But what’s unique about these marine mammals is that right now they’re the only species in the world known to have sustained high levels of carbon monoxide throughout their lives It is not natural for a human or laboratory animal to have high levels of carbon monoxide, even when ‘they show us that it protects them,’ Tift said.
The coolest part of this evolutionary trick, according to Tift, is that when a marine mammal dives “it will reduce blood flow to most organs like the spleen, liver, kidneys and intestines so they can maintain a constant flow of oxygenated blood to organs like the heart and brain, which require lots of oxygen.”
And then, when they come to the surface, these deep-diving mammals “reperfuse” the tissues that had been severed – that is, ischemia – during the dive. And so these marine mammals are constantly going through ischemia-reperfusion events.
“And so we wonder, is it an evolutionary advantage for them to maintain permanent high CO levels in order to prevent injury to their tissues? We don’t know that yet. We’re starting to address those questions right now,” said Tift.
Tift said it was important for the public to know – that the CO produced by cigarette smoke is in no way beneficial.
“While cigarettes can deliver low to moderate amounts of CO, they also introduce a plethora of extremely harmful chemicals into the body that can have very negative effects. The same goes for car exhaust,” Tift said.
Impacts of climate change
Potential health benefits aside, Pearson and Tift ultimately hope their study of seals will help show how much climate change is happening.
“Even though we don’t see what’s happening in Antarctica on a daily basis, I think this project will help us really understand what we’re doing and how it impacts other species as well,” Pearson said.
Tift said many scientists believe the biggest threat to society is climate change.
“It’s happening globally. This impacts animals all over the world. And for the most part, a lot of them can’t keep up with the rate that their environment is changing and that’s unfortunate,” Tift said.
What is of most concern is that these animals that live in Antarctica are rapidly losing their sea ice habitat.
In April 2022, The Washington Post reported on a study which showed that approximately a third of all marine life could disappear within 300 years. Princeton University researchers Justin Penn and Curtis Deutsch published their findings in the journal Science.
In the article, the researchers pointed out that the oceans absorb excess carbon dioxide, thereby depleting the oxygen in the water.
“And that will change the pH of the water making it more acidic,” Tift said, which in turn will start to affect species like krill, the main food source for crabeater seals.
The big picture of stopping the impact of climate change, according to Tift, needs to be pushed by lawmakers to make decisions to stop carbon dioxide emissions into the atmosphere.
Tift and his team continue to build the scientific record of climate change impacts with this study of seals.
“As scientists, what we’re trying to do on this trip is to focus on a few species, mostly crabeaters and their krill, and try to understand how they change,” Tift said.
The researchers will spend the next month collecting data – then they will return in May 2023 to reassess crabeater seal populations.
Want to follow their journey to Antarctica?
Twitter: @uncwtiftlab @LuisHuckstadt
*Editor’s Note: This original article incorrectly identified the ship’s name as Daniel D. Palmer. It’s the Nathaniel B. Palmer. Dr. Tift also clarified some of the science behind CO – and the impacts of apoptosis and ischemia on marine mammal organs. He also further explained the impact of sentinel species. Also, CO is best defined as a gas rather than a chemical. This article reflects those updates.
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