Alaska Insight
Threats to marine mammal health | Alaska Insight
Season 2024 Episode 13 | 26m 46sVideo has Closed Captions
What challenges are whale populations around Alaska facing?
Whales used to be a common sight around Kodiak Island, but in recent years, locals have observed fewer of the iconic mammals. A necropsy of a dead humpback whale performed in Kodiak seeks to answer questions about the health of whales in the area, but what other challenges are whale populations around the state facing? We speak with marine biologists on this episode of Alaska Insight.
Alaska Insight is a local public television program presented by AK
Alaska Insight
Threats to marine mammal health | Alaska Insight
Season 2024 Episode 13 | 26m 46sVideo has Closed Captions
Whales used to be a common sight around Kodiak Island, but in recent years, locals have observed fewer of the iconic mammals. A necropsy of a dead humpback whale performed in Kodiak seeks to answer questions about the health of whales in the area, but what other challenges are whale populations around the state facing? We speak with marine biologists on this episode of Alaska Insight.
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Healthy and productive ocean waters are crucial to sustaining the food chain that marine mammals depend on.
What can scientists learn about predator pressure and environment Stress on Alaska Whales from a recent whale necropsy on Kodiak Island.
A bunch of divots along the abdomen, which are cookie cutter shark bites.
You can see healed wounds from previous encounters with orcas on the flippers.
This whales definitely had been through a lot.
We'll talk with biologists about how whales in Alaska are faring and what that may indicate for the larger ocean food web.
Right now, Unalaska Insight.
Good evening.
The health of the oceans is important for all of us.
A better understanding of the environmental stressors for marine mammals and other sea creatures helps scientists learn about the health of the entire ocean ecosystem.
We'll hear from biologists about what they're learning.
But first, here are some of the top stories of the week from Alaska Public Media's collaborative Statewide News Network.
More than 50 people have been charged in connection with an international drug ring targeting Alaska communities, according to an announcement from federal authorities on Thursday.
US attorney for Alaska Lane Tucker said the group conspired to bring fentanyl cocaine, heroin and methamphetamine from Mexico into the state between 2022 and 2023, sending drugs to more than a dozen Alaska communities.
Court records show some members of the drug ring were inmates at Alaska Correctional Facilities.
Among the indictments are charges for the distribution of fentanyl, resulting in the death of a North Pole resident.
Six people are dead after a residential fire in the northwest Arctic community of Noorvik.
On Wednesday, state troopers and public village public safety officers responded to reports of the fire on Wednesday.
The remains of six individuals were found at the scene, believed to be a woman and five children.
Officials say the fire apparently started near a Toyo stove that was allegedly in poor condition.
Although the cause of the fire is still undetermined, at least one warehouse roof, two residential porches and eight boats have collapsed or sunk in Juneau over the course of two January storms that brought more than 60 inches of snow to the state's capital.
These two storms make this month the second snowiest January in the city's history, according to meteorologist Rick Fritsch.
Warming temperatures and rain over the coming days could dramatically increase the risk of further collapses.
Juneau harbormaster Matthew Creswell encourages boat owners to shovel their boats as soon as possible.
You can find the full versions of these and many more stories on our website Alaska Public dot org or by downloading the Alaska Public Media app on your phone.
Now on to our discussion for the evening.
Whales used to be a common sight around Kodiak Island, but in recent years, locals have observed fewer of the iconic mammals.
Last year, several whales were found dead near the archipelago.
Their bodies were emaciated and in extremely poor health.
As KMXTs.
Brian Venua reports.
Scientists aren't sure why the population is struggling.
He joined researchers for a necropsy of one of the whales in an effort to learn more.
It was a windy September day when a juvenile humpback was found dead floating around Chiniak Bay near the city of Kodiak.
The whales corpse was then towed to nearby Puffin Island, a short boat ride from downtown for the necropsy.
It's just so lucky that this was and that we were able to actually lasso it and drag it in and then have everybody available at the drop of a hat, Van Dale says.
Dozens of dead whales were reported around the Archipelago's communities in 2023, but this is the first one they've been able to dissect and study.
He says live well sightings have been rare.
This summer around Kodiak was very strange because usually you see many humpbacks around and they just it seems like they just left.
They went somewhere else, probably because there wasn't a lot of food around here.
So they went to where there was food.
Once the tide is low enough, a team of federal and tribal officials and several volunteers get to work.
They measure blubber thickness and take samples of the baleen, which acts like a filter and strings as small shrimp, krill and other foods from seawater.
Vandals says the humpback was likely a female subadult weaned from her mother, but still too young to mate.
He says she probably lived a hard life.
There's a bunch of divots along the abdomen, which are cookie cutter shark bites you can see heal wounds from previous encounters with orcas on the flippers.
So this this whale's definitely had been through a lot and survived a lot.
Cathy Burak is a veterinary pathologist with Alaska Veterinary Pathology Services.
She says it's unlikely the humpback was killed by a predator because it still has its tongue.
A favorite target for orcas.
She sees a possible clue in damage around her left eye.
Burak says this whale may have been hit by a boat.
It could be some torn tissue like the jaw or the tongue.
And then just above it, you can see where there's a very distinct kind of linear area of hemorrhage.
So I think we were already getting a feel that there was some kind of trauma The team then makes its first cuts to the whale's organs, which they'll sample and test for signs of disease.
Van Dale says the crew is lucky the wind is blowing and summed up their thoughts on the aroma of a rotting whale's organs.
How would you describe the smell?
‘Whaly there's there's really, like, nothing, nothing else.
Full results from the necropsy samples likely won't be available until late 2024.
The scientists say their best guess for now is that the young humpback was too weak to get out of the way of a ship and was struck in the head.
This was one of two whales in Kodiak found dead in poor health.
Scientists don't know why the animals are struggling, but they hope efforts like this necropsy will offer clues in Kodiak.
Brian Venua Joining me tonight is Mandy Keough.
Andy is the marine mammal Stranding coordinator for NOAA in Alaska.
And Matt VanDaele is also on hand.
Matt is the natural resources director for the Sunaq Tribe of Kodiak.
Welcome, both of you.
Thanks so much for being here this evening.
And Matt, of course, we just saw you in this video story.
Mandy, I want to start with you, though.
This necropsy was on a humpback and of course, we'll be discussing that.
But let's first discuss gray whale populations.
They've been in trouble since 2019.
Describe how much loss there's been in that population and what's known about the cause.
Yeah, So we have had an unusual mortality event with gray whales and that was declared in 2019.
And that means that there was an increase in stranded or dead, stranded Marine mammal species higher than what we normally see for the gray whales that some they're somewhat unique in that we saw increased strandings all the way from Mexico where they give birth in breed along California and the west coast of the U.S., throughout Canada and then throughout the Alaska coast, we saw increasing numbers of stranded, dead right whales, including up in the Arctic.
So these animals make really long migrations every year where they breed in Mexico, and then they come up to the Arctic in some Arctic waters to forage.
And so that there's been a total about 690 whales that have been confirmed stranded in throughout that entire geographic range in those since 2019 680 strandings.
How many of those?
Describe what exactly that means as far as how many were dead and how many were just caught somewhere.
So all of those animals were dead stranding and they were similar to what Matt and the Zodiac try are this the Zodiac tribe of Kodiak did?
Some of these animals had necropsies or postmortem examination, and that really highlights why their work with this unique tribe of Kodiak and other stranding partners are so important because we have these reports of dead, stranded animals, but we don't know initially why they're stranding and what the cause might be.
And so the postmortem examination and the necropsy that our partners do give us information on why these animals might be dying.
Is it a lack of food?
Is it a disease process?
Is it something like vessel strikes or other stressors that might be in the environment?
And without the public reporting these dead, stranded animals and without our partners doing the postmortem examination, we wouldn't have an idea of what's causing that strandings that we're finding.
Many warming ocean waters affect food availability, of course, as sea ice retreats, what temperature variations are being documented in the Bering and Arctic Oceans?
And how does that affect prey and predators?
Yeah.
So off the top of my head, I don't know the exact temperature increase.
I do know that they've had a loss of long term sea ice and retreating of sea ice, and that has large implications for the ecosystem within that environment.
And that trickles to marine mammals both at the same time with the great whale unusual mortality event.
We had a simultaneous in 2019 and 2020, an ice seal, unusual mortality event.
And so both these animals, the ice seals and the gray whales are foraging within the Bering Sea and the upper Arctic.
And so we're seeing that shift where we're seeing increased animals that are showing poor nutritional status or poor body condition, and we're seeing a loss or a reduction in of sea ice, and that impacts the entire ecosystem within that environment and ships what food may be available.
And both of those unusual mortality events have been is indicating that or they're associated with this shift in ecosystems and loss of prey and stay with you just for a minute more, Mandy.
In the necropsy story, Mat notes there were not a lot of humpbacks seen near Kodiak last summer or in recent years saying they may have gone somewhere else for food.
What are your thoughts here?
Do whales usually have a very predictable pattern of feeding and migration?
And this is quite unusual?
Or do they sometimes wander off of their normal path?
I think it's somewhat depends on the species, like with the gray whales and our car that unusual mortality event, they have a very distinct or established migratory path where they breed in Mexico and they forage in the subarctic and Arctic.
We do see some of those animals stopping along the way and foraging, like in California or in Washington.
Near Sitka, we're seeing an increase in gray whales that might be stopping to forage, whereas other species like the humpback, they're not they don't have they do have a larger migration.
But they don't have such a definitive end point like we see with the gray whales.
So it is possible that the humpback whales are foraging in different areas in either they're finding food along their migratory path or they're looking for new areas to forage.
But I don't know if anyone has actually documented that yet.
All right.
Thank you so much, Mandy, for getting us started.
Matt, I want to turn to you now.
The story we watched noted that several emaciated whales were found dead.
Were you able to study some of the others that were washing up?
And what do you think happened to them?
Yeah, we know we actually were able to do two full necropsies this year on whales, which is pretty remarkable.
A number of factors have to line up and able to do a full necropsy and you need to be able to get volunteers out there.
You need to be able to get out in a timely manner before the whale starts to decompose.
And it has to show up in a very fresh state in order to warrant a necropsy.
And so this year, we actually had to this the one that we just watched with the humpback, the one over Thanksgiving was a fin whale, a juvenile female fin whale.
And she definitely appeared to be in extremely poor body condition.
She was one of the skinniest whales that I've ever seen or we've ever seen.
But before then, in 2019, we were able to do a full necropsy on a gray whale right at the beginning of the unusual mortality event.
But this one appears that it probably was killed by orcas because the lower jaw was broken.
Most of the flesh and the skin was missing from the lower jaw and the tongue was missing as well.
And then in May of 2022, we were able to do another full necropsy on an adult male gray whale.
And he was also an extremely poor body condition, very skinny.
The blubber, it almost atrophied.
But usually what happens is if we do get a report of a whale and we are able to respond to it, usually it's in a very remote area and with that we partner with the Coast Guard and they're able to fly us around to do surveys and as conditions permit actually land in and at least get a skin sample and photos of any dead whales that we see to try to better understand what may have happened to them.
But we have definitely seen a large number that are in poor body condition, meaning that they're skinny.
When you see that number of them washing up dead in very poor condition, are you do you suspect that the death was caused because they are too weak to get away from predators or just because they're starving or eating the wrong things and becoming ill?
It varies.
I mean, all of the above, I would say even just simply starving to death, too.
I mean, but of course, when you're when you're in that kind of a weakened state, you're not going to be able to evade predators as well.
You may be going into areas that have more predators.
You're probably going to be more susceptible to disease, and then you won't be able to get out of the way of vessels, for instance.
So I would say all of the above are correct.
It's such a terrible scene to consider.
The story Notes Live whale sightings have been rare, but dozens of dead whales washed up in 2023.
Tell us about the scene and how people react and discuss these types of events in Kodiak.
Yeah, people are people are concerned.
I like to point out to that last year, which seemed to be an anomaly to us because of the lack of humpback and fin whales sightings during the summer when normally we see a lot higher numbers.
But since 2019, the unusual mortality event of gray whales is pretty well known here because we've we've had numerous dead whales washing up.
People are used to seeing a lot more gray whales around than they have been.
But it's it's a cause for concern, you know, on the ecological level, on the psychological level and also on the commercial level, too, of of lack of abilities for whale watching cruises, for instance.
Are any of the whales either in the humpback or the gray whale population tagged so that you can get a sense of where they are moving and how they're moving?
Is it possible that they're taking a somewhat different migration route and that might be part of what's happening?
I'd like to onto Seward Amandi, if I may.
So there are some researchers that do tag animals, not actively the humpbacks and the gray whales, but one thing that's really unique for both of those species is that they have unique markings and so they can actually use photo identification.
So you don't you may not have to tag an animal to be able to track where it's moving.
And so for humpback whales, there's their sites like Happy Whale, where you as a public can upload your photos.
And those are often the underside of the fluke.
And it will tell you where your whale has been seen and it will add it to the record of that whale.
So that's one way we can track them.
Similarly with gray whales, the modeling that's on their back or their dorsal fin is unique between individuals.
And so researchers have been able to identifying those and tracking those and matching where they are.
The gray whales are a little harder to match, but the humpback whales, there's a very long history of researchers taking photos of the underside of the flukes.
So the public, if you're out there and you're taking photos, you can upload them to sites like Happy Whale, which provides you information about the whale you saw.
But then it also adds to what we know about where these animals are being sighted.
And when the young whale in the story, the necropsy was done on a juvenile whale.
Is it possible the suspicion was possibly a ship strike and that the young whale was too weak to get out of the way?
Is it possible that that weakness, because it was a juvenile, could have come from the length of the migration, or is it clearly a lack of decent food?
So humpback whales, there's different distinct populations segments and they have different migratory paths.
So there are animals from Mexico, from Hawaii and Central America, all within the Alaskan waters.
So just seeing where an animal is, we don't always know how far the migration wise photos and genetics can provide that information.
So some of the samples that Matt and the Sumac tribe of Kodiak collected might tell us where which DPS that was from.
And I did talk to Kathy Burak, who's a veterinarian, who did the necropsy, and there was evidence of trauma around the eye, but we're not sure whether or not that is potentially a vessel strike because there wasn't the associated when they got into the carcass, there wasn't the broken bones that you would expect.
So we do know that killer whales ramming animals.
And so we know that there's indication is of a blunt force trauma in this humpback whale.
But we didn't see enough to differentiate whether that was a vessel, a killer whale or something else.
But it's possible that that weakened state of that animal, whatever that trauma was caused by, made it more susceptible.
Are there particular types of creatures that whales thrive on that are most at risk in changing ocean conditions?
Or is it a general food abundance concern?
So within the marine environment, the ecosystem, there is a chain or a web across the different trophic levels.
So unfortunately, if one level starts shifting or changing, it will cascade to the other levels.
Both the gray whales and the humpback whales use baleen, and so they're filter feeders.
So they're feeding on the smaller animals for gray whales, animals that are within the sediment layer.
And then for humpback whales like you, forces in krill and smaller fish.
So they're kind of feeding on the lower trophic levels.
But we do see in some areas that it seems like when we see warming waters or shifts in sea ice extent, that the entire food web can be impacted and it carries up to the larger predators like whales or sea lions or seals.
Are there more orcas being observed in Alaska waters or are they just more seem to be more aggressive toward this whale population?
So and Matt, you can please jump in.
So the killer whales or orcas, there are different eco types.
And so we have the transient or the Big Big's whale that are known to prey or feed on other marine mammals, and they can specialize and large whales.
And like Matt mentioned, those animals seem to target the jaw and the tongue of those large baleen whales, or they might forage or focus on seals and sea lions or smaller cetaceans.
We do see an increase in that population.
The big killer whales in some areas of Alaska and Vancouver, we are seeing an increase in that population.
And so one of the things we are looking at and we can look at with this training records and the photos that our partners or the public take is trying to assess are we seeing an increase in killer whale predation or kind of a hotspot of killer whale predation?
And as Matt mentioned, they have this very within Alaskan waters.
They have a very characteristic injury.
When we when we find large whales that have been killed by a killer whale and its tearing the lower jaw peeling blubber off and they seem to focus on the tongue.
So if the public if you see a carcass and you refer to this training hotline and we can share that number, it's 8779257773.
Sometimes with just the photos, we can assess whether or not it was a killer whale predation.
But if we can connect with our stranding partners like this unique type of Kodiak, and they can actually get out to do a full postmortem exam, then we learn more information like was the animal also in poor body condition?
What was the age class?
You know, Clark Genetics that find out.
Is it one of the listed endangered species of whales we have in Alaska, or is it more of an established population?
So both of those pieces of information are super helpful If the public finds either entangled or distressed marine mammals or dead stranded marine mammals, regardless of the condition that carcasses in.
We're interested in hearing about that.
And then we partner with local folks to see whether or not who are trained and experienced in doing necropsy or sampling.
Matt, are you seeing an unusual number or different behavior by orcas?
I wouldn't say an unusual number.
We've definitely been seeing having a pretty dramatic increase in sightings.
They're coming in front of town much more frequently than they used to in the past.
Whether this is an increase the population or a change in behavior.
I really can't say at this point, but I like to echo Mandy's point about the importance of public involvement and public outreach and, you know, letting us know when you see a dead or distressed marine mammal, even things she was saying about pictures of light as would be very helpful and trying to better understand what the population is doing, Is it is it increasing?
Are they going into new areas that they haven't really been seen before?
The public are our eyes and ears.
There's only so much that we can do and so many places that we can be.
And also with funding constraints too.
So having an engaged and interested public is very much appreciated.
Yeah.
And the interesting thing about water whales, sorry, is similar to the humpback whales.
There are researchers that do photo identification.
So if you take a photo of their dorsal fin with a white saddle patch behind them, there are sites or researchers you can share your sightings with and then they will know who that individual is.
Is it in an unusual area?
Are they venturing out to new areas or hanging out in certain areas?
And that's another way that the public can help our better understanding of these marine mammal populations.
All right.
Thank you for that.
And we only have about a minute or so left here.
Many the avian flu concern.
There's an outbreak among elephant seals in Argentina, Argentina.
Has this happened before?
An avian flu spreading to marine mammals and then spreading between them.
How concerning is this?
So there have Ben Stiller over events where avian influenza and there's two types of avian influenza and the one that we're talking about or concerned about, or the high path avian influenza which causes diseases in birds and in mammals, often the mammals, the terrestrial mammals that have been exposed are largely scavengers.
So they're eating dead or injured sick birds.
We have not found any high path avian influenza in marine mammals in Alaskan waters yet.
But with any increase or shifts in disease is it is a concern right now, all the samples that have been collected have demonstrated in bird to mammal infection.
And so we are interested in collecting more samples and hoping hopefully the Argentinean samples will also be able to show whether or not it's a mammal, a mammal.
But right now it seems to be bird to mammal, or at least that's what so far they found.
But again, it highlights the importance of us understanding when we are seeing dead marine mammals, regardless of whether it's a lack of food or a new disease or an expansion of a disease, we want to be able to track those dead carcasses and then when possible, sample.
Then people who like Matt and his volunteers who are trained to safely sample and authorize to sample marine mammals.
That's how we're going to learn or document whether or not avian influenza or another pathogen is in the marine mammals in Alaska.
All right.
Thank you so much to Matt and Mandy for being with us this evening for this important discussion.
The health of the oceans affects the health of the entire planet.
What scientists can learn from studying marine mammals will help us all better understand the challenges in the marine ecosystem and hopefully provide ideas for how to meet them.
So the oceans and the creatures who live in them can thrive into the future.
That's it for this edition of Alaska INSIGHT.
Visit our website, Alaska Public dot org for breaking news and reports from our partners stations across the state.
While you're there, sign up for our free Daily Digest so you won't miss any of Alaska's top stories of the day.
Thanks for joining us this evening.
I'm Lori Townsend.
Good night.
Alaska Insight is a local public television program presented by AK