South Pole 8. Avian Flu in Antarctica

In this episode of "South Pole," host Clark Marchese is joined by Dr. Meagan Dewar, a wildlife disease specialist from Federation University Australia, to explore the alarming spread of avian influenza to Antarctica. Dr. Dewar shares insights into how this disease has reached such remote regions, its impact on local wildlife, and the ongoing research aimed at understanding and mitigating its spread. As they discuss the broader implications of wildlife diseases exacerbated by human activity and climate change, this episode sheds light on the challenges facing Antarctica's unique ecosystem and the global efforts needed to address these emerging threats. Tune in to understand the complex interplay of natural and human-induced factors in wildlife health at the poles.

Episode Guest: Dr. Meagan Dewar

More information about Dr. Meagan Dewar here 

Browse Dr. Meagan Dewar’s publications on Research Gate

Follow Dr. Meagan Dewar on X

Read about strategies for controlling Avian Influenza here. 

Episode Transcript  and more information on the Pine Forest Media Website

Follow Pine Forest Media on Instagram @pineforestmedia

Hosted, produced, written, and edited by Clark Marchese 

Cover art and PFM logo by Laurel Wong. 

Theme music by Nela Ruiz

Transcript:

[00:00:09.290] - Clark

Hello, and welcome to South Pole, the podcast that explores everything Antarctica. I am your host, Clark Marchese, and today we are talking about wildlife diseases and how the avian flu made its way all the way down to Antarctica. You may have seen in the news in the last couple of years an increasing number of stories about the avian flu or the bird flu and how it's spreading across the globe. If you've been to the grocery store while this is happening, you may have seen all the eggs are either gone or the ones that are left are the price of diamonds. Well, avian flu would be the reason for that. Unfortunately, Unfortunately, this disease is spreading so far in part because birds have wings that fly, and they have used those wings to fly the virus so far down that it has now reached the pristine and remote environment of Antarctica. So today we're going to dive into this pressing issue with the help of Dr. Meagan Dewar, a renowned specialist in wildlife diseases in Antarctica. Dr. Dewar is a lecturer at the Federation University, Australia. Her research focuses on host microbiome interactions and the pathogens affecting Antarctica and subantarctic wildlife.

[00:01:29.760] - Clark

In this episode, we'll explore how the avian flu found its way down to Antarctica and the effects it's having on the region's wildlife and the mitigation strategies being implemented to combat this spread. With that, let's get started. All right. Welcome, Dr. Dewar. Thank you for coming on the show today. Maybe Today, I'll have you start by just introducing yourself and telling us a bit about your research.

[00:02:04.210] - Dr. Meagan Dewar

Yes. I'm Dr. Meagan Dewar. I'm a wildlife biologist from Federation University in Australia. Most of my research focuses on host microbes in marine wildlife. So mainly looking at penguins, flying seabirds, and sharks.

[00:02:19.430] - Clark

Okay, so the coolest job ever. One question I like to ask is, has your research ever taken you down to Antarctica? And if so, maybe you can tell us about some of the projects that took you down.

[00:02:29.620] - Dr. Meagan Dewar

Yeah, I've been down a few times to Antarctica and just see seeds, and I went down twice. So most of my research focuses on looking at the microbial community in animals, but to understand, I guess, who lives there and what organisms are present. We need to get a baseline understanding of who's there on a regular basis, and then we can start to look at how that community might change under different conditions. Also, I've started doing a lot of disease surveillance work as It enables us to see if there's any new and emerging pathogens that have arrived in the area. For the last few seasons, I've been heading down to Antarctica, mainly on the peninsula, working with some of the tourist vessels and going to different locations and collecting fecal samples from different wildlife species to study the microbes. Then this year as well, unfortunately, avian influenza was a big concern. I had an expedition recently in March to go down and actually survey for the presence of avian influenza.

[00:03:34.270] - Clark

So your research does focus on a number of different diseases and pathogens among the Antartic wildlife. But would you say then that the avian influenza is the most concerning at the moment?

[00:03:43.630] - Dr. Meagan Dewar

So a lot of my, I guess, work has been focused on doing disease surveillance in general, looking at all potential pathogens, trying to understand which ones might naturally occur within the population. But probably the two more recently that have been of concern is, of course, avian influenza, and the other one is pustrella multisida, which causes avian cholera. But some of our recent work has shown that it is a pathogen that seems to circulate within the populations, but doesn't necessarily cause outbreaks all the time. So understanding what factors causes that to start to become a pathogenic and a concern to animals.

[00:04:22.790] - Clark

If we're trying to understand where these diseases come from, how they enter the population, would you classify them as naturally occurring, or do we see a direct link between human activities and human influence?

[00:04:36.500] - Dr. Meagan Dewar

You have got some that will naturally occur and circulate within the population, but then certainly we have got some that are going to be of more concerned with climate change. As temperatures change around the world, species migration paths are changing. We have species moving down towards the Atlantic but never were there before. Also, some of the species that do come down there are acting with other animals they never would have normally. Therefore, they can start to get pathogens from each other that way. But we also have that risk of introducing things as well. When we visit, if we're not following really good biosecurities measures, but then also with our farming practices and things like that. Having diseases spread over from agricultural practices into wildlife and then that moving down towards the Atlantic. It's a combination of of natural, but also climate change in human-radiated.

[00:05:34.630] - Clark

Also, one thing I'm just super curious about is with climate change, obviously, there's a concern of ice melt. Is there a concern about pathogens that were perhaps once frozen in the ice, but now that it's melting, that they could potentially spread? Is that something that your research touches on at all?

[00:05:52.790] -Dr. Meagan Dewar

Yeah, we haven't done, I guess, as much research on this as the Arctic region. Definitely in the Arctic, they have found some pathogens like anthrax and so forth being exposed from carcasses that were buried for long periods of time in the permafrost. There is that risk that there are pathogens that managed to survive in those frozen habitats that could escape. But there hasn't been, I guess, a lot of research on those frozen landscapes.

[00:06:23.030] - Clark

Okay, well, then I suppose we will continue to watch this space. But back to the topic of the day, which is the avian influenza. Most people have probably heard of this in the news, partly because you go to the grocery store and the eggs are now $20. But for anyone who hasn't heard of it, can you just tell us a little bit about this disease? How it affects birds? How does it spread? Does it only affect birds? Maybe just a general understanding of what the disease is.

[00:06:46.530] - Dr. Meagan Dewar

Yeah. So avian influenza is a type of influenza A virus that predominantly does infect birds, but can infect other species as well. But predominantly birds, which is often why it's referred to as avian influenza. It's generally grouped into two main categories. We have low pathogenic avian influenza. These are variants that cause little to no disease in animal species. They're often found in many wild birds and seabirds, often are reservoirs of low pathogenic avian influenza. Then we have our high pathogenic avian influenza, which causes severe disease and illness in both poultry and wild birds. Often has a very high mortality rate were associated with it. So generally what happens is low pathogenic avian influenza over for wild birds into poultry, and then it mutates into a higher pathogenic variant. Normally, we have outbreaks just within poultry farms. Any outbreaks that you have, as you know, your eggs are now $20. You'll go through any infected flock, the entire flock will be killed to try and prevent the virus spreading out any further to other locations. Every now and then, you used to get some spillovers into wild birds, but you'd have local outbreaks, nothing really big.

[00:08:06.390] - Dr. Meagan Dewar

But then in about 2021, we started getting live spillovers into sea birds. We got a massive outbreak that's been happening globally around the world. So generally, it is spread by respiratory droplets, animals sneezzing, coughing, the normal way flu gets transferred, but then also what we call the fecal oral root. This is where infected birds will defecate into the environment, most likely, usually into water sources, and then other healthy animals go and either drink or bathe in that water source or in the environment and ingest the virus that way. For a lot of our scavengers, they will often get infected by eating infected birds. So they're the main routes that it travels. In terms of the only birds get it, no. Mouthles have always been susceptible, including ourselves. It is a zoon zoonotic disease, but generally it was more, again, when predators and so forth would eat infected birds, they would get the virus. However, we are starting to potentially see some other changes happening with the most recent virus.

[00:09:15.700] - Clark

Okay, vocabulary word, zoonotic disease, simply put, is an infectious disease which can pass from animals to humans. Rabies, Lyme disease, and yes, COVID-19 are famous examples. But then I guess the reason we're We're talking about this today is because the avian flu has made its way all the way down to Antarctica. Can you tell me what we need to know about it? Is it contained? Is it not contained? Yeah.

[00:09:40.510] - Dr. Meagan Dewar

So, sadly, in February, we confirmed our first case in Antarctica. On my recent expedition in March, we confirmed it at four new locations. We have confirmed cases down pretty much both sides of the entire peninsula in skewers. That's a large predatory scavenging sea bird that we get down there. Unfortunately, it's not contained. It's not something that's easily contained in the wild areas. Unfortunately, when we were down in March, we did detect a mass mortality event in skewers. There was around 50 birds that were dead out of about 130 that were on the island that we were at.

[00:10:20.800] - Clark

Oh, my gosh. What are the potential consequences of continued uncontrolled spread?

[00:10:26.630] - Dr. Meagan Dewar

If we have a look, the best example of understanding What might happen is what we saw in South Georgia, sub-Antartic Island, just South America, where we've seen, unfortunately, large mass mortality events in Southern Elephant's Hill pop-ups and a number of sea birds there, and it spread quite rapidly throughout this season. It's very dependent on the species that it gets into and which ones will be more susceptible. Because although the species haven't been affected before, it's difficult to predict exactly which ones are going be the most susceptible. But given penguins live in very large, dense colonies, it has the potential to cause severe losses at many colonies. If we look at to the north, the great skewers had 60 to 70% of their populations lost at some location. If we got those losses down in Antarctica, that could have significant impacts on a lot of species that are already under threat from things like climate change, fisheries, habitat destruction. We could have huge consequences.

[00:11:32.940] - Clark

Yeah, 60 to 70%, that's alarming. You mentioned that it can also spread to mammals. Other than elephant seals, do we know of any other antartic mammals that have been affected by this yet?

[00:11:43.950] - Dr. Meagan Dewar

Some antartic firs seals as well have also been affected. They're the two main seal species that have been impacted that we do know of at the moment. The other species we get down south, like the Leopard Seals and Prabeida Seals and Wadel Seals, often breed or congregate in large groups like the other two species do. It can be quite difficult to know if they've been impacted unless you find a carcass. Unfortunately, many animals will die at sea, and we won't ever get to count those or know what happened.

[00:12:18.750] - Clark

Okay. I know the ocean is really big, but I'm going to ask because you said one way that the disease spreads is by entering a water source. If it enters the ocean or marine mammals carcasses enter the ocean environment, is Is that a concern for wide scale marine contamination?

[00:12:34.360] - Dr. Meagan Dewar

Probably not at this scale. The ocean is very large, so it'll be quite diluted, and it often fresh water sources, pools of water, and so forth. So smaller bodies of water will be affected. The ocean should dilute it quite a bit more. The risk of, I guess, animals dying at sea is scavenging on those that otherwise potentially wouldn't have been affected.

[00:12:56.120] - Clark

Okay, so we also mentioned how climate change can increase disease risk, and we know that climate change is human generated. But I guess the question of the day when it comes to the avian flu is, did humans cause this? Is this our fault?

[00:13:09.120] - Dr. Meagan Dewar

In one part, yes. So especially with our farming practices and things like that. As we know, the virus is generally from low pathogenic avian influenzas spilling over into poultry farms and then where our high path viruses then come from. And then you're having, I guess, large mass scale farming practices, poultry, and these being close or near water sources where wildlife are. It does, I guess, help create the high pathogenic forms and then the spread as well.

[00:13:45.510] - Clark

Are there any public health implications for humans with the spread of avian flu throughout Antarctica or elsewhere?

[00:13:52.250] - Dr. Meagan Dewar

It is a zoonotic disease, as we said. So humans are susceptible to this virus, and sadly, people have been infected. However, those have generally been people working in farms, people working in live animal markets, and so forth. So generally, people with close contact with infected animals. For the general public, the World Harbor Organization still considers the risk quite low. Generally for tourists visiting Antarctica, there are a lot of security measures and safety guidelines in place. As long as tourists are following the approach limits that we have, so generally guests are to stay 5 meters from wildlife. That's generally to reduce the stress and disturbance on the wildlife. But that actually also helps to reduce your risk as well because you're not up close and personal with the animals. For people working with wildlife in close proximity, as long as they're wearing the appropriate personal protective gear, the risk is very low for them being infected. There is the risk, but there are measures in place to reduce those risks.

[00:14:56.420] - Clark

I suppose that those measures to protect ourselves can also serve as basically the best that we can do to limit our contribution to the spread, at least through our immediate interactions with these wildlife. But aside from minimizing our own risk and minimizing how we contribute to the spread in a direct sense, is there anything that we can do to try and control the spread among wild populations?

[00:15:18.740] - Dr. Meagan Dewar

Yeah, unfortunately, once it arrives in the populations, there's not a lot we can do to stop the spread amongst the wildlife. Unfortunately, we just have to watch and monitor what's happening with the populations, so certainly reducing our spreading of the virus or the potential that we could do that does assist, but also looking at strategies back home. Potentially, hopefully, we're going into winter now. Most of the wildlife populations have left Antarctica, but then there's the risk it will get reintroduced next year. Looking at strategies and ways of reducing the spread of the virus back home so that a new variants and things don't make their way down.

[00:16:02.980] - Clark

All right. Well, as we start to round out the episode, is there anything that we missed today that you think is important to talk about with the avian flu or wildlife diseases in Antarctica more broadly?

[00:16:15.120] - Dr. Meagan Dewar

I guess the big thing is there's not a lot that it has been done. It's still an area that we don't fully understand, which has been one of the biggest challenges in preparing for avian influenza that we We don't have a lot of knowledge and research on pathogens down there. Historically, everyone thinks it's so isolated, it's one of the most pristine places in Earth, but now we know that's not the case. We do need to start to look at wildlife disease in more depth and get a better understanding of how pathogens might arrive. So new pathogens, unfortunately, bird flu is probably not going to be our last outbreak we see. So starting to learn from this outbreak, but continuing that research as well. So that's probably the biggest thing is advancing our research and getting more investment into that.

[00:17:14.510] - Clark

Okay, well, then I'll also thank you for the work that you are doing to advance our knowledge in this space. To try and end on more of a positive note, I'm going to ask you, what is your favorite thing about Antarctica?

[00:17:27.720] - Dr. Meagan Dewar

Well, I think It's a combination between the wildlife that you get to see down there. Amazing, massive colonies. You can go to places like the Danger Islands where there's colonies of nearly 300,000 penguins. But then as you sail past massive iceberg, and it's just a crazy, amazing landscape and wildlife colonies that you don't get to see anywhere else. It's very hard to explain, but it's something that does draw you in and you get addicted.

[00:18:02.930] - Clark

Well, I mean, who wouldn't love a Penguin? But also this is a podcast so people can't see, but the background of your Zoom is a bunch of penguins and seals and birds. So it's clearly a passion of yours. That's amazing.

[00:18:13.330] - Dr. Meagan Dewar

Yeah.

[00:18:13.760] - Clark

I guess the last question I have for you is where can people follow your work and stay up to date on this topic?

[00:18:19.900] - Dr. Meagan Dewar

Yes. I guess website, Federation University Australia. Also on Instagram, Dr. Meagan Dewar. These are the main areas that We post and also on X as well. I post a fair bit of my research stuff there. Yeah, hopefully some new stuff to come out soon.

[00:18:39.870] - Clark

Okay, perfect. Well, I'll put links to that in the episode description so that people can find you easily. This is the part where I say thank you again so much for coming on today, for teaching us about this, and for the work that you're doing in this space.

[00:18:51.140] - Dr. Meagan Dewar

Thank you.

[00:19:06.050] - Clark

Okay, a major thank you to Dr. Meagan Dewar. I guess the major takeaway is we really got to change our farming practices because it seems like the outbreaks in Antarctica are fairly likely to occur again next season. I really don't want a bunch of penguins to die, and I really don't want to get stuck inside my house again for two years. Irresponsible animal agriculture has really caused a lot of problems for us, and we really to take this seriously. As I said, there will be some links in the show notes to follow this issue going further. I think that's all I have for you today. So thank you for listening, and I'll see you next week. You've been listening to South Pole. You can find more information about this week's guest and links to their work in the episode description. Cover art for the show was done by Laurel Wong, and the music you're listening to was done by Nila Ruiz. I am your host, Clark Markese, and this episode was produced and engineered by me. So if you found it interesting, send it to someone you know. South Pole is part of a larger network of sciencey podcasts called Pineforest Media.

[00:20:18.880] - Clark

We've got one on plastic, one on drinking water, and a couple of new ones coming out soon. You can find more information about us in the episode description or on our website at pineforestpods. Com. We are also on Instagram and TikTok at Pineforest Media. If you love the show and you want to support science communication like this, a five-star rating across platforms and a review on Apple podcast is one of the best things you can do to help us reach more people and for the entire network to grow. All right, thank you to all of you who have made it this far, and we'll talk soon.