Scientists Study Dolphins As Model Of Human Health

IRA FLATOW, host:

You're listening to SCIENCE FRIDAY from NPR. I'm Ira Flatow, and for the rest of the hour we're going to talk about more parallels between humans and marine mammals, and we're going to focus on a marine mammal that, it turns out, has quite a bit in common with us, and those are those lovable dolphins.

Think about it. They have very big brains, like humans. They suffer, believe it or not, some very similar viral infections. They get common colds like we do, and the papiloma virus. I bet a lot of people didn't you didn't know that, these kinds of things that the dolphins are suffering from.

And they even have a condition this is really surprising. They have a condition that resembles diabetes, and they're not drinking all those milkshakes, eating the chips and the soda and the other junk food that's in our modern human diet, which makes you wonder: Why would dolphins even have this sort of diabetes if they're not eating that kind of stuff?

If there something beneficial that they would have diabetes, and does it tell us something about our own human diabetes and maybe a way to treat it or cure it if these dolphins can sort of turn it on and off, as they can, which we'll learn?

Let me introduce my guests. Dr. Stephanie Venn-Watson is a veterinary epidemiologist. She's also director of clinical research at the National Marine Mammal Foundation here in San Diego. Welcome to SCIENCE FRIDAY.

Dr. STEPHANIE VENN-WATSON (Director of Clinical Research, National Marine Mammal Foundation): Great to be here, Ira.

FLATOW: Nice to have you. Dr. Hendrik Nollens is a clinical assistant professor of zoological medicine at the University of Florida, and he's also based here in San Diego. Welcome to SCIENCE FRIDAY.

Dr. HENDRIK NOLLENS (Clinical Assistant Professor of Zoological Medicine, University of Florida): Pleasure to be here.

FLATOW: Let's talk, Dr.�Venn-Watson, first of all, about the dolphins you study. Where do they live, how do they get there, where do you study them?

Dr.�VENN-WATSON: Sure. Well, I get to brag about amazing population of dolphins with which we work. These are the marine mammals that work with the Navy Marine Mammal Program, and it's a population of about 60 to 70 dolphins, and their main job for the Navy is to find and detect underwater objects, whether it's objects lost at sea or mines or underwater swimmers and even recently some humanitarian de-mining efforts, looking for catching, getting some of those World War II mines that are lost in the ocean.

FLATOW: So they let you come in where they're housed here in San Diego, or...

Dr.�VENN-WATSON: They are...

FLATOW: And they let you come in and study them?

Dr.�VENN-WATSON: They live in San Diego Bay. Well, there's an exchange for that. In exchange, my job, as a veterinary epidemiologist, is really to take care of that population of dolphins.

What we're going to talk about with the diabetes, we'll get into an accidental mistake that's leading to an exciting new direction...

FLATOW: Well, tell us about it right now.

Dr.�VENN-WATSON: Okay, I couldn't wait.

FLATOW: Yeah, I know.

(Soundbite of laughter)

FLATOW: I find it very surprising. I love when these serendipitous things happen, right? How did you discover about this, the diabetes in the dolphins?

Dr.�VENN-WATSON: Sure, well, we started with a study that we thought was going to be quite boring. We were going to compare CBC(ph) and chemistry. So basically, when you and I go to the doctor, and we get that series of 30 blood tests run, we do the same things to look at the health of the dolphins.

And so we just wanted to determine some normal reference ranges, comparing the dolphins that had fasted overnight to those that had been recently fed, and when we got the results, we were very surprised to find that the changes during the animals that had fasted, they didn't match other animals' fasting states; they matched results from studies looking at people with diabetes versus those without diabetes.

And these are big studies comparing huge populations of people, and we're seeing these changes in the same population of dolphins, the same animals where, when they fast in the morning, they are diabetic-like, and when they eat, the all of a sudden aren't diabetic.

FLATOW: Is that how humans are, the same way?

Dr.�VENN-WATSON: That is not how humans are.

FLATOW: No, I think it's just the opposite, isn't it?

Dr.�VENN-WATSON: It's very interesting. It's usually comparing different groups of people with disease or without disease for these animals to be able to switch something on and off.

FLATOW: They can switch it on and off at will.

Dr.�VENN-WATSON: We think, or driven by something, whether it's food or diurnal rhythms, but it's quite amazing, and there appears to be a reason for that.

FLATOW: If you feed them junk food, do they go into the diabetes, like, Type 2 that we have in humans?

Dr.�VENN-WATSON: Very interesting question. Actually, 40 years ago, the father of marine mammal medicine, Sam Ridgeway(ph), did this work, where and we dug through the Navy archives and pulled out thousands of handwritten data points, turned them into an electronic database and found that when dolphins are fed sugar, their blood glucose goes up and goes way up and stays up for, like, 10 hours, and that's very similar, or actually is a hallmark, of diabetes in people.

FLATOW: Wow, 1-800-989-8255 is our number, talking about dolphins and the similarities they have to people. Also here in San Diego, if you want to step up to the microphone, always had a question about Flipper? No, or something like your dolphins are not named Flipper, are they?

Dr.�VENN-WATSON: No, we have no Flippers.

(Soundbite of laughter)

FLATOW: That's good. We had enough of one dolphin named Flipper, I think. 1-800-989-8255. So what can you learn about by studying the diabetes in the dolphins about how that might work with people?

Dr.�VENN-WATSON: Sure, so what does this all mean to us?

FLATOW: Okay, that's a good question.

(Soundbite of laughter)

Dr.�VENN-WATSON: Well, first of all, this genetic fasting switch, this potential for a dolphin to have a genetic fasting switch that can turn diabetes on and off is exciting. So if we could find that switch and control it in humans, it could potentially control the precursor for Type 2 diabetes, which is insulin resistance, and could lead to the cure for diabetes.

And we're a long ways away from that, but the dolphin genome has been mapped, and obviously the human genome has been mapped, and we can start looking for those fasting genes and when they switch on and off and potentially controlling them.

FLATOW: Do we know how they're able to are they cues, obviously, from the food, or is there other cues? Are there mental cues that might be happening?

Dr.�VENN-WATSON: It's we don't know the answer yet, but the potential is, or the most likely answer is, when they eat and when they don't eat. So when they fast - basically they eat fish, which have very little sugar in it, and we know that their big brains need lots of sugar. So how do they keep that sugar going in their blood when they're fasting?

And so the argument is, is that with Type 2 diabetes helps the liver create sugar and feeds that brain during the fasting state. So it may be the fasting.

FLATOW: Yeah, interesting. Hendrik Nollens, I didn't know a I guess I should've thought that a dolphin can catch a cold, right?

Dr.�NOLLENS: Yes, they sure can.

FLATOW: Yeah, we catch cold viruses. Are there viruses in the water that they swim around in?

Dr.�NOLLENS: Yeah, we well, let's backtrack a little bit. A few years ago, we didn't anything, or much, about viral diseases in any marine mammals, including dolphins, and over the last few years we have learned a lot really quick, and one of them is one of the viruses that we did detect and did work up was called a para-influenza virus, which is a virus that is associated with common cold in humans, among other species.

And actually, when we worked it up, it turned out that the virus causes an exact a very similar disease syndrome. Some animals do not show any clinical signs. They're fine. They just, you know, fend it off. Other ones are just more vague. They don't feel well and they want to stay in bed all day and don't feel like eating, and other ones do develop more obvious respiratory signs. So yeah, they do get a common cold.

FLATOW: Could they be sharing that with us? Can we can they pass you know, I'm thinking of the avian flu, the swine flu. Could there be flus out there or viruses out there that have a mixture of all those different genetic components, and maybe there's a bit of a dolphin in one of those that we catch?

Dr.�NOLLENS: Well, probably not so much this cold virus, but there are viruses one thing we have learned is that there are viruses in the marine environment, in the ocean, that do meet that have all the same characteristics of the recent, big, emerging diseases, the recent big, emerging disease viruses.

So if we think of HIV and SARS, West Nile virus, these are all RNA viruses that came from wildlife and that had the potential to jump hosts, and one of the things that we have learned is again, not this cold virus, but that some of these other viruses do have some means of interaction with human viruses and even recombine and swap pieces of genetic information. So it's not, it's not impossible.

FLATOW: But no one has been able to show it yet.

Dr.�VENN-WATSON: Well, there is a virus group, actually, from California sea lions. It's a calicivirus, it's called San Miguel sea lion virus, that historically has made its way onto land in the U.S. and actually set up shop and caused disease in domestic pigs.

And this virus has been found since in fish and amphibians, and even in humans it's associated exposure to this virus is associated with chronic, active hepatitis. So there are precedents.

FLATOW: You both work with dolphins. How do you tell when a dolphin is sick? I mean it doesn't come up with, you know, with its little Blue Cross card and say...

(Soundbite of laughter)

Dr.�VENN-WATSON: They're amazingly good at masking disease, and that would...

FLATOW: They mask the disease.

Dr.�VENN-WATSON: They are very good at it. It would work to their advantage out in the wild. You don't want to show a weakness out there. So a lot of times what's good about things like the Navy Marine Mammal Program is that they're able to watch. The trainers know their animals really well, and so when a dolphin is sick, usually the first sign is just the appetite is decreased. So even if...

FLATOW: Stop eating.

Dr.�VENN-WATSON: Yeah, they stop eating, and they just may seem a little tired.

FLATOW: Do they cough or sneeze or...

Dr.�VENN-WATSON: They can cough.

Dr.�NOLLENS: Yeah, sometimes they do. The main the most sensitive marker for telling us an animal is sick or not are the trainers. The trainers do work with these animals, and they know them every day, and they will even pick up on subtle things like saying this animal is slow. Usually he swims in front of me. Now he's behind me. These sort of things.

So they are key in picking up early disease in these animals because, exactly, they've been selected to hide their weaknesses. In the wild, you can't tell at all. You can't tell until they are on the beach or dying, really.

FLATOW: So they're not getting a runny nose and the eyes and things like that. Could you tell that that was happening?

Dr.�VENN-WATSON: Usually, infections are picked up the next - after seeing that dolphin doesn't have a very good appetite, would be taking a blood sample, and a veterinarian can go and look to see if there are changes that are very similar to that that we would see in people.

FLATOW: So you do take blood samples of them.

Dr. VENN-WATSON: We do. And I love to brag about that as well, that...

FLATOW: Are they're good patients?

Dr. VENN-WATSON: They are excellent patients.

(Soundbite of laughter)

FLATOW: Do they have a choice?

(Soundbite of laughter)

Dr. VENN-WATSON: Actually, what's amazing is these - the dolphins in this population give voluntary blood samples.

FLATOW: Now, is that like volunteering in a military? I need a volunteer for a blood sample, you know?

(Soundbite of laughter)

Dr. VENN-WATSON: Well, see, we have to - we get cookies and orange juice in exchange, and they do it with nothing and - nothing else in the exchange, so there's got to be something good going on there.

But if a blood sample is needed, even a urine sample, the trainers, the veterinary technicians can go down to these dolphins and they stick their tail out of the air and they give their samples. It's quite amazing. They live in the open bay and they stick with us. It's a great partnership.

FLATOW: Hmm. Do they get a lollipop when they...

Dr. VENN-WATSON: Well, then they might have high blood sugar levels.

FLATOW: But they get rewarded with their fish? You know, you see trainers giving...

Dr. VENN-WATSON: Well, sure.

FLATOW: Yeah.

Dr. NOLLENS: Maybe a big herring or something.

FLATOW: A big herring.

(Soundbite of laughter)

FLATOW: A little sushi. For doing this. Is there a season - now, we have cold and flu season. But are there seasons for dolphins getting sick in the water?

Dr. NOLLENS: There are. And it is the - it varies by disease. There's certain diseases that we see in the wild animals up and down the coast in spring such as the same calicivirus. Again, with this flu virus, we actually saw the peak of this virus around calving season and, again, with astroviruses, which is a virus that causes diarrhea in most other species. We can see the exposure peak in spring season, which is usually around calving, which makes sense because you have all these immunologically naive animals who come into the population that are susceptible to any other pathogens or viruses, bacteria that may be circulating.

FLATOW: Mm-hmm. Is the water that we think is, you know, as clean and beautiful and clear, is it swimming with viruses like the air, if we could see the viruses here?

Dr. NOLLENS: It actually is. Twenty, 30 years ago, we thought oceans were completely sterile, that they were dead zones. And we've known for quite a few years now that that's not true, that the ocean is actually packed with bacteria.

But even in more recent years, we've now learned that the seawater contains tons of viruses. One microliter seawater contains - can contain several million virus particles. Now, most of those viruses are only able to infect the bacteria that also float in the seawater, but some of them may very well have human or animal disease potential too.

FLATOW: 1-800-989-8255. Yes, sir.

Mr. CRAIG STEVENS(ph): Yeah, hi. Craig Stevens (unintelligible) about as far as you can get from marine mammal these days. I had a question for Dr. Venn-Watson. Do you think your findings would apply to wild animals as well or is it a result of the Navy diet or captivity?

Dr. VENN-WATSON: It's a good question. We are afforded an amazing opportunity to track these animals very closely and we're looking at very subtle elegant trends that you pick up over tracking these animals for 10, 20, 30 years. So -but it is a question that we have.

And - so we're looking - we do - we are looking at wild populations. The problem is, even when we get urine and blood samples, we don't know the health history of the animal, when did that animal last eat. So we're out there trying to answer the question, but we're also looking at dietary differences that may be between wild dolphins and dolphins at the Navy, like do wild dolphins fast overnight and if they don't, then are there things that we could change that could potentially decrease any negative side of diabetes?

But the exciting part of this research is that it seems - diabetes seems to be a natural healthy state for these animals.

FLATOW: Mm-hmm. We're talking about dolphins this hour on SCIENCE FRIDAY from NPR here in San Diego, where they have lots of dolphins, lots of dolphins and many places to see them. Talking with us, Dr. Stephanie Venn-Watson and Dr. Hendrik Nollens.

Did you ever find that there might be an ideal diet to feed dolphins in captivity? Can you - you know, they're here, they've (unintelligible) free, you know, we know wild animals are usually healthier when left in the wild.

Dr. VENN-WATSON: Well, we're looking at the diet in animals. And actually, we're really excited about the fact that when you're looking at health indicators of populations and when we look at it, there are many different ways that you can look at the health of a population, annual survival rates of animals and whatnot. And dolphins at the Navy, as well as other big institutions, are actually starting to show that survival rates of these dolphins are actually equal to or not(ph) higher than those in the wild.

But we are looking at, is their potential that our quality of our diet is actually too good for these animals. We're giving them very high protein fish and maybe we need to make it a little simpler for them sometimes.

FLATOW: Let's see if we can get a quick call before the break here. Let's go to Diane in Brooklyn, New York. Hi, Diane.

DIANE (Caller): Hi. How are you?

FLATOW: Hi there.

DIANE: I was wondering - I had heard that dolphins are one - are the only animal or mammal that consciously commit suicide, is that true?

FLATOW: Hendrik?

Dr. NOLLENS: I'll try to answer that one. To the best of my knowledge, no. The only scenario that would come even remotely to this, I would say, is actually the stranding events. So marine mammals, seals and sea lions are able to move around on land and freely. So they - for those animals who come on land is not a problem, is not uncommon.

Now, what we do find is that animals - dolphins or whales that are sick or out of place or whichever reason they do sometimes beach themselves on land, and actually, that reflex is almost the opposite of a suicide because what - we don't know. We - probably 99 percent of stranded animals, we actually never know what caused them to strand. But one of the thinking is - and it seems it's a very logical one, is that these animals are actually feeling weak. They feel they're dying, and so they're trying to prevent drowning.

FLATOW: Mm-hmm. One of the things I was learning from research is that just on the other side of flipside is that dolphins are one, among the few animals, you know, that have sex for fun, right?

Dr. NOLLENS: They do.

FLATOW: Not just to procreate.

Dr. NOLLENS: They do.

FLATOW: That's why Flipper was dancing on the water a lot.

(Soundbite of laughter)

Dr. NOLLENS: They do. There are some interesting YouTube videos out there.

(Soundbite of laughter)

FLATOW: And they mate face to face, right? Like people.

Dr. NOLLENS: They do. Yeah. Usually the female will swim on the surface and the male will come up underneath and roll over and - so, yeah. It's...

FLATOW: That's the good side of studying dolphins. And there are a lot of other things that dolphins do that are similar to people. And one of the most - thing that we think about all the time is the size of their brain. We have to take a break. When we come back, I want to talk about how that affects the research that you do. You know, we think that these are very intelligent creatures. We look at that from their brain size. Does that affect what kinds of research, thinking that they're intelligent and maybe they have different, you know, different consciousness that we would think than other animas have - does that affect the kinds of research that you might want to think about doing on them because you dont want to hurt them, their feelings, and things like that?

So we're going to take a quick break and come back and talk about lots more with Dr. Stephanie Venn-Watson, who's was a veterinary epidemiologist, and Dr. Hendrik Nollens, a clinical assistant professor of Zoological Medicine.

Our number, 1-800-989-8255. Stay with us. Please, come up here in the audience. I'd like to ask you a question. We'll be right back after this short break.

(Soundbite of music)

FLATOW: I'm Ira Flatow. You're listening to SCIENCE FRIDAY from NPR. We're here in San Diego talking about dolphins with Dr. Stephanie Venn-Watson. She is a veterinary epidemiologist at - and she's also director of clinical research at the National Marine Mammal Foundation here in San Diego. Dr. Hendrik Nollens is a clinical assistant professor of zoological medicine at the University of Florida and based here in San Diego. Our number: 1-800-989-8255.

And let me just - let me ask you, Dr. Venn-Watson, about this question I've always wondered about. If I live in the ocean all the time and I get a cut, it's going to be an open wound, you know? Here I can put a Band-Aid on it, put whatever - how does a dolphin deal with getting injured like that? And they have real skin like we do because they're mammals, right?

Dr. VENN-WATSON: They do. It's a great question that we're looking forward to answering even more. But what's observed out there, which is fascinating, is that dolphins in the wild, it's been well - they have been well documented to sustain injuries, and sometimes it's from propeller wounds that run deep because of interactions with boats or whatnot. And some of these animals do get infections and they die.

There are other animals that go on to heal these wounds and here they are sitting in the sea of bacteria and viruses that Hendrik was talking about. And they not only heal these wounds but they go on to reproduce, which is a sign of (unintelligible) is a kept as a productive member of society.

FLATOW: Do they have special healing powers that we dont have? Does their skin heal faster? Or

Dr. VENN-WATSON: It's believed that their immune - they might have a really neat immune system that's specific to their skin. So we're even looking at things collaborating with outside researchers looking at the potential for these regenerative cell or these cells that can help them heal quickly - that's present in their adipose tissue, their fat.

FLATOW: Mm-hmm.

Dr. VENN-WATSON: And humans and other animals also have these cells in their fat, but is there something special about the dolphin cells that can teach us some neat things about healing ourselves?

FLATOW: So they heal quicker than we do.

Dr. VENN-WATSON: We believe so. We believe that if we were well, we know - if we were in the same environment as them and sustaining the same wounds, we certainly will not heal the same way that our dolphins do.

FLATOW: Okay, let's go to the audience here. Yes...

MADELINE (Caller): Good. My name is Madeline(ph). And Dr. Venn-Watson, you mentioned that you didnt have any dolphins name Flipper. But I was wondering, if you do name your dolphins and how you feel about the phenomenon of naming research animals.

Dr. VENN-WATSON: Sure. Well, the first is yes, they have names and we care for them tremendously. These are highly valued animals both personally and for the mission that they do for the nation. Their job is not to be research animals. These animals are there to help do what they do. They find objects underwater and they help the Navy and protect our nation. A nice side effect of having this population is that our job is to take really good care of these animals. And as part of taking good care of them is monitoring their health.

What has happened is we have accidentally found these amazing simple discoveries just by monitoring health trends in animals and caring for them. So it goes much more into this one health approach where caring for one species, we can care for them all. Is the dolphin going to be a lab animal? No. It's not.

FLATOW: Why? Why?

Dr. VENN-WATSON: I just - I dont think it's going to happen. I think there is an affection that people have for marine mammals, including all of us here at the foundation in the Navy. These are very special animals, but there's a lot we can learn from them by working with them.

Dr. NOLLENS: Mm-hmm. Marine mammals are

FLATOW: Hendrik...

Dr. NOLLENS: Marine mammals are actually also the - one of the only animals that have a special protection act specifically dedicated to them. They're protected under the Marine Mammal Protection Act, so experimental research on it is very limited. And they're even protected to the point where in the wild you're actually not allowed to approach dolphins. They can approach you. They have permits, but you don't have permits to go after them.

(Soundbite of laughter)

FLATOW: Hmm. It's like penguins in Antarctica.

(Soundbite of laughter)

FLATOW: Do they - do they have any other special privileges that, you know, just about - beside not doing research on them? And I'm sure that comes because we think they're almost as intelligent as we are, right? Their brains are huge compared to their bodies.

Dr. VENN-WATSON: They do. They have - if you look at something called - a fancy word, encephalization quotient or EQ - this is the measurement of their actual brain size compared to their expected brain size for their body size. And humans are the biggest - we get that bragging right - at 7.4. Dolphins come next down on the line at 5.3. And it's amazing when you look at something like a rhesus monkey which we typically say is close to human, is down at 2.4.

FLATOW: Mm-hmm.

Dr. VENN-WATSON: So dolphins and humans do have these very similar large brains which, dating back to the diabetes picture, these large brains need really -need lots of sugar, available sugar to feed them. And so we think that's quite why dolphins and humans with something as obscure as a disease like diabetes, that might be why they have something in common.

FLATOW: Mm-hmm. Let's go to the audience here. Yes.

LAURA (Caller): Hi. My name is Laura and I'm a AAAS policy fellow in the NOAA Climate Program Office. I have a general question. So there are so many challenges associated with studying marine diseases - for example, trying to isolate pathogens out of the water column or understanding transmission rates when you have such an open system; what are some of the emerging areas of technology or maybe new collaborations that are being formed to get a more comprehensive understanding of diseases in the oceans?

Dr. NOLLENS: I think this is probably a question for me. The - I'd say there are a few things. First, you need to get the right people to come together. Working - learning diseases from wild animals is really hard, because usually you can only get to dead stranded animals on the beach, which, majority over time are too decomposed to even get a, you know, a cause of death of these animals.

In our case, we actually, for our program, we - our program or our lab is a product of a collaboration between the U.S. Navy Marine Mammal Program, the SeaWorld Parks, Hubbs Sea World Institute in San Diego and then University of Florida. And so, combined, there are a lot of - this is a big group of animals who are under human care and have medical records that go back decades and so on.

So this is an incredible resource for learning about which pathogens these animals are exposed to and then what it actually does to these animals. So that's probably key in...

FLATOW: Mm-hmm.

Dr. NOLLENS: Then the second part of what we do is, once we have an agent characterized whether this is a virus - in our case, a virus but other people will find bacteria or parasite or fungi - we go out and go and service some of these wild populations or auto collections to see - to get an idea for how well - how these agents behave in the wild versus, you know, animals that are under human care and receive medical care.

FLATOW: Mm-hmm. Thank you. Let's go to the phones to Tanya(ph) in Anchorage. Hi, Tanya.

TANYA (Caller): Hi.

FLATOW: Hi, there. Go ahead.

TANYA: I was wondering about picking up tuberculosis from a dolphin. And the reason for my question, just as a quick background, is I went to college in Texas and worked for the Marine Mammal Stranding Networks. Before I went, I took a TB time(ph) test. And the time test showed that I didn't - I mean, it was negative. I didn't have any TB exposure. After I was done working with the dolphins, I ended up getting sick after working with the dolphin - got pneumonia, took a TB time test and they diagnosed me with TB. And it was suggested, but they weren't sure, that I could have picked from the dolphin. I was wondering if there's any merit to that.

FLATOW: Andrew?

D. NOLLENS: Tuberculosis in humans is caused by a bacteria called mycobacterium tuberculosis. And various marine animals, both sea lions in New Zealand and cetaceans - so dolphins - sea turtles, get mycobacterium infections. So - a bacteria that belong to that same group of mycobacteria. Now, of all the reports of mycobacteria infections in dolphins, none of them are actually with M tuberculosis. None of them are the group of bacteria that causes these lung abscesses, such as M tuberculosis or M avium would do.

So, if you were to - on a serologic test - were to cross-react with a mycobacterium from a dolphin like M abscesses or verinum, I would not be surprised at that. But I would be very surprised if the M tuberculosis came from a dolphin. I would think that's just - I would expect that to be just a coincidence of timing.

FLATOW: Okay. Tanya?

TANYA: Thank you.

FLATOW: Thanks for an interesting call. But close enough, you're saying, that the different bacteria that...

Dr. NOLLENS: They do belong to the same bacterial family.

FLATOW: Yeah. Yeah.

Dr. NOLLENS: But the bacteria themselves are very different.

FLATOW: Yeah. Okay. Sir, right here.

BRIAN MOSELEY(ph): Hello. I'm Brian Moseley from the Kansas City Zoo. And my question was, do you ever find like, isolated populations of marine mammals that are susceptible to these diseases or is the water all mixed together, or do they have like, surfaces that they contact or something like that?

Dr. NOLLENS: That's a long and complicated answer. We do find there are - well, first of all, I should say we know very little about the dynamics of disease in wild populations, in part because - by and large because we don't get access to these animals, and also for a long time (unintelligible) exist to study them. What we do know is that some things, for example, a bacterial kidney infection in sea lions called leptospirosis, is very, very common in sea lions in Northern California. Down here in Southern California, it's very rarely seen. So there are differences.

Now, what these differences, you know, what is the reason for these differences, geographical differences, we don't know, because there's a pretty good water exchange between Northern California and Southern California. Animals migrate up and down the coast. I wouldn't be surprised to see differences between the Atlantic and the Pacific because, you know, they're geographically isolated. But there are smaller scale, geographical trends too.

FLATOW: Thank you. Another question about - you were intriguing me by talking about the sea of viruses that are swimming in the ocean. And one of those that I was thinking about and I've heard about is the genital papiloma virus. I know there's a human papiloma virus that might lead to cancer. Is there something similar in that sea of viruses that might be affecting the dolphins?

Dr. NOLLENS: There is. And it probably doesn't come from the sea water. It may more be related to their sexual behavior, maybe, which is purely hypothesis. But, no, dolphins do get genital papiloma virus infections. And what is actually unique about them is that they are the only other species other than humans that we see multiple type infections at the same time. So where you can find a - if you take aside over actually like a - the equivalent of a pap smear, you may actually be able to - you can find up to six, seven, eight, nine papiloma viruses in there at the same time.

And the only other species that has been reported is in humans. And in humans, there's actually the risk of malignant cervical neoplasias or cancer increases dramatically with the number of papiloma viruses present. In dolphins, there are no reported cases of cervical cancer.

FLATOW: So - no cervical cancers in...

Dr. NOLLENS: No. There are cancers, but no cervical cancers.

FLATOW: Well, you'd want to know why, wouldn't you?

Dr. NOLLENS: Exactly. It would be great to know why.

FLATOW: That's a great - would be great to know why they have the same claim(ph) where they're not getting the cancers from.

Dr. NOLLENS: Exactly. And maybe we can actually learn something from it to help prevent human disease.

FLATOW: Yeah. Let me ask you this. Stephanie, could - if you fed humans who eat a dolphin-type of diet, like very high in protein - we've heard of all - would that hurt us like - we feed dolphins junk food, they get something - if we eat a very high protein, would we get hurt? You know, our kidneys are sensitive to all those protein, right?

Dr. VENN-WATSON: Yeah. It's a good question as far as what are the - what happens when a person of type 2 diabetes then potentially eats a high protein diet? There have been some short-term studies, three to five-week studies, in which people of type 2 diabetes were fed very high protein, very low sugar diet. And in those cases, these are people who are not on any other treatment, blood sugar levels were under better control and it seem like they were heading in the right direction. These were only three to five-week studies.

FLATOW: Mm-hmm.

Dr. VENN-WATSON: So the flip side is, as you had mentioned, Ira, the high protein diets can have a very negative impact on kidney function. So there's a lot more that needs to be studied.

FLATOW: Mm-hmm.

Dr. VENN-WATSON: An interesting subpopulation are the Eskimos. Alaskan Eskimos has, for a long time, eaten very high protein. Our diet is much like those of dolphins. And those people, this population, has obviously sustained and thrived very well on this diet. Interestingly, now that they're starting to get more and more high carbohydrate-type of diet shift into them. The incidents of diabetes is starting to poke its head in that population.

FLATOW: Wow. Wow. It's a good figure. I want to thank both of you for taking time to be with us today. Dr. Stephanie Venn-Watson is veterinary epidemiologist and director of the clinical research at National Marine Mammal Foundation here in San Diego; Hendrik Nollens is a clinical assistant professor at - of zoological medicine at University of Florida, thank you.

And have you sit by here because we're now bringing in Flora Lichtman, our video producer, on SCIENCE FRIDAY from NPR.

I'm Ira Flatow.

And Flora actually went down and visited you, did she not? And we have our Video Pick of the Week with you photographing the dolphins, Flora. Very interesting stuff up there on our Web site.

FLORA LICHTMAN: Yes. We got to visit the population of dolphins, the Navy dolphin platoon. I don't know what...

(Soundbite of laughter)

FLATOW: Did you call it a platoon, Stephanie?

Dr. VENN-WATSON: That would be a new one. (Unintelligible).

(Soundbite of laughter)

FLATOW: Okay.

LICHTMAN: And see some of the health care that they get. And it really - I mean, it's something to be envied. It's a very thorough.

FLATOW: In this era of getting our own health care...

LICHTMAN: Yeah.

FLATOW: ...those dolphins are getting...

LICHTMAN: It's a pretty good. And we saw one of these blood tests. And also, we saw - let's see, what else - a mouth check. I was amazed at how giant the tongue of a dolphin.

FLATOW: Yeah?

LICHTMAN: It's huge, yeah.

FLATOW: Yeah.

LICHTMAN: And also, a dolphin ultrasound.

FLATOW: And they allowed you to take pictures of them, very happily.

LICHTMAN: They're very obedient, yes.

FLATOW: Yeah.

LICHTMAN: They didn't seem that shy. But they were sort of tremendously cooperative...

FLATOW: Mm-hmm.

LICHTMAN: ...with the trainers.

FLATOW: And you watched the - Stephanie or somebody or one of her assistants throwing blood from the dolphin?

LICHTMAN: Yes.

FLATOW: Just like she described?

(Soundbite of laughter)

LICHTMAN: Yes. They'd volunteered its tail willingly.

(Soundbite of laughter)

LICHTMAN: We were taken around by veterinarian Cynthia Smith, who works with Stephanie.

FLATOW: Mm-hmm.

LICHTMAN: And so, we got a full tour of how you give a dolphin a checkup. And you can watch it on our Web site.

FLATOW: Yeah, just go to our sciencefriday.com Web site and there's the Video Pick of the Week up there on the left side. And you were telling me that these are like - they're not sort of retired dolphins of a long time, right, Stephanie? They can live 20 or 30 years?

Dr. VENN-WATSON: They do. And, in fact, the Navy - 40 to 50 years.

FLATOW: Forty to 50 years. So these are sort of veteran dolphins.

Dr. VENN-WATSON: They are.

FLATOW: Veteran military dolphins.

LICHTMAN: Some are semi-retied, greatly. So we...

(Soundbite of laughter)

Dr. VENN-WATSON: That's right. Actually, we were. There's no term such as retirement, because they're happy working. So if we have - if we can (unintelligible).

FLATOW: Uh-huh. And how long did you spend there? You spend there a while, all day.

LICHTMAN: Yeah, we were there in the morning. It was, you know, it's a nice break from New York. I'm sure (unintelligible)...

(Soundbite of laughter)

LICHTMAN: ...(unintelligible) of snow. But one amazing thing that we heard about is how, you know, these dolphins are deployed occasionally to do work for the Navy and they have to be actually carried, you know, on a plane. So there are all these elaborate ways of transporting the dolphins that we had sort of never thought about.

FLATOW: Right.

LICHTMAN: They even have a beluga whale tank for the (unintelligible).

FLATOW: Wow, on the plane. And it's always a great stuff. Well, you can see Flora's adventure with the dolphins up there in San Diego on sciencefriday.com. Great film. And go over and click on our Video Pick of the Week.

Thank you very much, Flora.

LICHTMAN: Thanks, Ira.

FLATOW: And we'll see you back in New York next week.

That's about all the time we have for today.

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