In this episode
Colleen and Adam discuss:
- endangered sea turtle stranding in Cape Cod Bay and how the the New England Aquarium sea turtle hospital operates
- the effects of climate change on sea turtles
- the current science and research on sea turtle rescue and rehab operations
Timing and cues
Interview p1 (3:26-13:49)
Interview p2 (14:35-28:27)
Editing: Colleen MacDonald
Additional editing and music: Brian Middleton
Research and writing: Pamela Worth
Executive producer: Rich Hayes
Host: Colleen MacDonald
Colleen: Adam, welcome to the podcast.
Adam: Oh, thanks for having me. I'm happy to be here.
Colleen: So, you know, I've been wanting to talk sea turtles on the podcast for a long time, and, you head up the Sea Turtle Hospital at the New England Aquarium, where I volunteer every Saturday. I think it's safe to say that we're both turtle geeks. So, before we get into the specifics of the work at the Sea Turtle Hospital, let's just talk about sea turtles in general. How many species of sea turtles are there?
Adam: So, there are seven species of sea turtles. All but one call the Atlantic Ocean their home, you know, the ocean that we're very close to. You a lot closer to every day than I am, but... So, you have six species that are known as the cheloniid, or the hard-shelled species, and then you have the one species that is more of that leathery soft shell, or the dermochelyidae, which is the leatherback sea turtle. You know, turtles that are... The other are the Kemp's ridley, that we see most often here at New England Aquarium. And then loggerheads and greens. And then you will also have olive ridleys and flatbacks and hawksbills as well, that round out our seven species of sea turtles.
Colleen: How much do we know about sea turtles, about their lifespan or where they go, or how many there are?
Adam: You know, that's a great question. We do know a fair amount about what they do. There are certainly times in each of these species' lifespans that we know very little about. For instance, you know, these turtles, when they hatch and head out into the ocean, there's what a lot of folks call the lost years, from when they head back into the water till when they return as juvenile animals back to areas that they frequent. And so, these are, these years between zero and anywhere between three or four, to a lot older than that, when you consider some of the loggerheads don't come back until they're closer to being in the 20s, as well as green sea turtles. So, we know a bunch, but we certainly are missing out on a lot more about what's happening with these turtles.
Colleen: So, which of the turtles are endangered?
Adam: So, all species are threatened. They have kind of broken up the groups of the turtles to what they call distinct populations. So, even though the green sea turtles as a group are doing okay overall, there are certain sections or distinct populations that are threatened, some that are vulnerable, so, throughout the world, when you look at various areas, it will kind of depend on where those turtles are. You know, green sea turtles in the water are threatened. When they're on land, they're under a different classification. The Eastern Pacific Leatherback is critically endangered, with very few animals left in the wild. Whereas the Atlantic Leatherback is a threatened species, so, doing much better than its Pacific, you know, kin.
Colleen: So, let's talk about our unique situation here in New England. I mean, while many of us, including sea turtles, love Cape Cod, you know, that amazing hook of land that creates Cape Cod Bay can really be life-threatening for sea turtles. So, tell us what happens every year as winter approaches.
Adam: Yeah. So, summertime, you'll get these turtles that are moving into Cape Cod Bay, and these are all juvenile animals that we see. And again, we're talking about the cheloniids, or the hard-shelled sea turtles, specifically, at this point, you know, they, at some point, migrate into Cape Cod Bay, whether that's from the Mid-Atlantic, which is most likely where we're seeing the Kemp's ridleys come, or loggerheads or greens, which, again, could be entering the same way. They could be migrating north, as the waters warm up. You know, Cape Cod Bay in the summer is great for them. Perfect temperature, perfect forage, but then, yeah, winter approaches. You start getting those cold winds coming in, and, you know, we start layering up, as humans, but the turtles decide they wanna head south to warmer water. Unfortunately, due to the shape of Cape Cod, it's not an easy southerly swim. They would actually have to swim north and east, as we all know, if you're looking at a map, and then swim around the hook and get back out into open water where they could swim south to warmer waters.
These are animals that do these big migrations, you know, using the magnetic poles, and so hitting a land mass, it's counterintuitive for them to head north again and then over east, and then around, the assumption is they just kind of swim back and forth, trying to find openings to get as far south as they can. And as they're trying to figure that out, it gets colder and colder, finally gets to a point where they are physiologically not able to really actively try to move out of the Cape, and they kind of just will shunt their blood, they float to the top of the water, and that's when the winds blow them into the beaches, and our friends down at Wellfleet Bay Wildlife Sanctuary go out and find these turtles and, the live turtles come up to us, and we do our work from there.
Colleen: Right. it's amazing. The volunteers at Audubon go out, when the winds are pushing the turtles onto shore, they'll go out and walk the beaches to find them, right?
Adam: Correct. Yeah. So, they have it pretty much down to a science down there as far as, depending on the wind, the wind direction, how long the winds have been blowing, when to go out and walk certain beaches to find the turtles there.
Colleen: So, then tell us what happens once they've collected these turtles on the Cape. What is the next step in their recovery?
Adam: Yeah. So, once they determine if the turtle's alive, or it's suspected to be alive... Some of these turtles, you know, for all intents and purposes, you know, when you look at them, and they look dead, but there's subtle nuances in trying to determine if they're alive or not. But if there's a question at all on whether or not a turtle's alive, they send them up to us here in Quincy, and at that point we bring them in. Again, we establish which turtles look better than others, and we triage through them. They all get their heart rates taken. They get a quick evaluation on, you know, how reactive they are to stimulation. If their heart rates are low, they'll get a dose of epinephrine to get the heart kick-started a little bit. They'll get photos. Turtles that are really not doing very well at all will go to our clinic for a deeper evaluation.
They all get a number on them, and a band that has a number as well, so we can kind of determine who's who. Especially when they get further into rehab and they're all swimming together, it's hard to figure out, you know, which turtle's which turtle. They will then go to a area where they swim at 55 degrees, fresh water. That helps rehydrate a little bit, also helps maybe kill off some of the epibiota or the various living things that are on the shells of the turtles. And from there, again, we're monitoring them as they swim, to determine which turtles might need more help out in the clinic, versus turtles that can maybe get a standard dose of fluids and antibiotics.
All the turtles will start on a, what we call a prophylactic dose of an antibiotic, just to make sure that as the turtles regain health and re-warm up, you know, bacteria that live inside the turtle also are starting to warm back up, and so we wanna make sure that any harmful bacteria is kind of taken care of before, and by taking care of, we don't want the bacteria to kind of get a stronghold on the turtle before that turtle's eating actively and doing more of that kind of road-to-recovery type work that we get once the turtle's fully warmed up. The warming-up process takes several days, you know, to...you know, they will go to 55 degrees, and then 65, and then into the mid 70s is where they ultimately end up.
Colleen: So when they come in they are cold-stunned. Can you define of that and describe the health issues appear as they warm up?
Adam: Sure. Yeah. So, cold-stunned, if you think about it, it's hypothermia, basically, that we would describe in humans. But, again, you know, these turtles have been out in these cold waters for weeks, maybe a couple months, as we get to the last batch of turtles. Certainly, so, as they warm up, you know, we do see a variety of things that are wrong with these turtles. The biggest thing is, you know, from radiographs, we see very heavy cases of pneumonia. Some that are really bad. These turtles are out kind of inhaling that cold water, and so it just gets into the lungs and really causes some issues there. We certainly also will see trauma. You know, this year we've had a lot of fractures. Not really sure exactly where those are all from, whether it's from hitting rocks. You know, there's some that look like they could have been prop strikes or could be certainly some predation that may occur. But we've seen a lot of various fractures to the shells, to the soft tissue. You know, we'll sometimes see eye issues where there's some scratches. Sometimes when they land on the beach, scavengers might get to them, whether that's gulls or coyotes. Certainly, they're vulnerable to those animals when they hit the beach.
So, it's a gambit of things that we see, as well as a lot of deviations in their blood chemistries. A lot of these turtles are kind of down to minimal muscle, so we see a lot of low blood sugars, or hypoglycemia, because these turtles have broken down all those fat and muscle stores.
Colleen: And then how long does it take to treat the turtles and get them ready to be released back into the ocean?
Adam: Yeah, so, you know, given the number of turtles we get into the facility, we can't keep them all, so we certainly will send turtles out to other facilities. from what we're seeing, we at least what we think are the worst of the worst. Certainly, you know, we, you know, can't know everything that's happening with the turtles, with the amount of animals that come through and as we're triaging, so we do have to ship turtles out all over the country. It's a huge effort and really, the ones that come in earliest, sometimes it's weeks before they head out, if we get them down south. Otherwise, these turtles will be with us until we drive down...you know, March or April is usually when we might do our first round of ground transports to release. And so, those turtles sort of been here three, four, five months, you know, and then we get turtles that will be here through, August, September. So, really, anywhere between about a month to six to eight months is on average what we're seeing. And then there's always those few cases that could take more than that. we've had some cases that take multiple years before they're released. Our hope is that every single turtle will be released that come through this program.
Colleen: And what's the success rate been?
Adam: So, it's varied over the years, but really, in the past, five, six years, we're hovering at that kind of about a 80% to 83%, 84% survivorship. So, every year we look back, we kind of debrief on the season, and try to figure out what we did well, what can we do better. And, you know, a lot of the research that has been done, you know, through the New England Aquarium over many years has just helped get that survivorship up and keep it at a really good rate. you know, when you think about it, if there weren't these programs here, all those turtles would be dead. You know, they're not going to get better and go back into the ocean and survive. You know, it's cold. They're not gonna survive a winter in New England. So, you know, it's, I think, a great percentage of survivorship.
Colleen: So, the Kemp's ridley sea turtle, which is the predominant sea turtle that we bring in to the hospital, is critically endangered. When the aquarium start taking in turtles, and can you see progress that points to the species population recovering?
Adam: The New England Aquarium's been taking turtles in, really, as long as the Wellfleet Bay Wildlife Sanctuary has been finding their turtles. We were kind of that kind of default go-to for Bob Prescott and that group. And certainly, we have small numbers in the '70s and '80s of turtles that would come in, you know, single digits. And really, would just do our best to get those animals back to health or moved on to areas around the country for them to continue and get them back in the ocean. It really wasn't probably until, like, the late '80s, early '90s that we started to really do more work. And then certainly by the mid '90s, late '90s, we started seeing more and more turtles, and really starting to hone in on the best way to get these turtles back to life, and really work on getting them back out to the ocean.
So, tens and twenties of animals, sometimes higher numbers, getting close to the 100 benchmark. And certainly, as progress was happening down in the Gulf of Mexico, the Kemp's ridley itself was part of a big binational agreement between the United States and Mexico. There was a oil spill that had happened that was pretty close to Rancho Nuevo, Mexico, which was the only natural nesting beach, or the big natural nesting beach of the Kemp's ridley. And so, the thought was if something was to happen to that beach, it would just wipe out, this turtle species.
So, they decided to move some of those turtles up to South Padre Island in Texas, and there was a big agreement between the two countries. For many years, they would bring the eggs up to Texas, they were hatched, and they would kind of be released off South Padre. So, now we do have the two nesting beaches going. Back in the late '40s, there was that video that'd come out with the nesting arribada the Kemp's ridleys, showing something like 47,000 nesting female Kemp's ridleys down at Rancho Nuevo.
And then, you know, fast-forward to the '80s and then you were down to a couple hundred nests per year. So, certainly a huge decline in nesting. And with that, also, with that agreement, along with the introduction of the turtle excluder device on the shrimp trawls, which allowed turtles to escape those trawling nets when they were catching shrimp, and just the introduction of the Endangered Species Act in 1973, to help protect this species, we really did see a very large increase in nesting numbers. You know, we're now roughly around 20,000 nests per year. There was a bit of a drop-off in 2010, which coincides with the BP oil spill, but we're back close to the number prior to that. You know, we're not seeing these big gains that they saw in the '90s and early 2000s. So, there's still a lot of questions as to why, the nesting hasn't continued to increase the way it has, whether, you know, the oil spill had anything to do with it. Certainly, what's happening down there obviously does affect up here because, you know, we have a bigger pipeline of turtles, obviously, with more nests that are happening.
But certainly, the Endangered Species Act being in place has really helped, not only the Kemp's ridley go from hundreds of nests to almost 20,000 nests. So, with that, you're looking at probably roughly between 7,000 and 9,000 females, given that the females lay anywhere between two and three nests per season. So, you know, when you look at the total number of nests, you kinda have to put those numbers knowing that each turtle has laid two or three of those, so that's where we're getting that 7,000 to 9,000 number of nesting females. However, there's obviously the males that mated with the females, just offshore. There's also, you know, the females that aren't nesting that year. There's the different age classes of turtles, so it's hard to get an exact number of turtles, of Kemp's ridleys, that are out there in the wild.
Colleen: Right. There's no turtle census.
Adam: No. No, they're not...
Colleen: So Adam, one of the aspects of volunteering at the aquarium that I love is the fact that the staff is actively doing research to better understand turtle behavior. What are some of the questions you’ve been trying to answer?
Adam: Again, it's all trying to, you know, further the science behind saving these animals. You know, we certainly were on the forefront of stress hormones in the work that we did in the early 2000s. A lot of that now kind of helps dictate how transports and releases, and how we treat these turtles.
A lot of folks look at these turtles, and they have their hard shells, they survive a lot, they've been around since dinosaurs, all that. So, you know, you think of these turtles as being very hardy. And certainly, years ago, we used to, when we would do treatments, take 'em all out of the water, line 'em up, and just kind of bang 'em out one by one. But then we really started thinking about, like, what is going on with these turtles? Are they feeling any stress? What happens? So, you know, we started looking at that, and really, we did start seeing this stress hormone, corticosteroid, that showed that these turtles do undergo stress, even though they're not showing it. They kind of just sit there. You know, some kind of flap around a little bit. But their levels of stress certainly peaked. And, the researcher at the time, Dr. Kathleen Hunt, noticed that these turtles had some of the highest stress that she had ever seen in any of the species that she had worked with.
Colleen: And what about the research that you’re doing once the turtles have been released?
Adam: Yeah, so a lot of work is going on, you know, it's trying to figure out more about what are these turtles doing out in the ocean. So last couple years, we've been implanting these acoustic tags into turtles, under a pilot study, to see how that works. Because, you know, most of the tagging, that's more of an active tagging. Satellite tags only stay on for a few months. Maybe, if you're lucky, a year or so. Especially with these young turtles that are growing, the tags will kind of fall off, or the battery life is only good for so long. And so, with these internal tags, we're gonna get a lot longer data. As these turtles migrate up and down the coastline.
Colleen: Right. Which is really fascinating. When I've been in on a few Saturdays, we've pulled up the map to see, where specific turtles that we've released, where they are, and where they're traveling, which is really fascinating.
Adam: Yeah, I know. It's really interesting. A lot of the initial work that we were doing is kind of just showing survivorship. It's that whole question, like, does rehab change behavior, or do the turtles, when they're released, do they go back to being a normal "wild turtle," or did we change behavior in some way that make them more susceptible to when they get back into the wild, not, make it. And really, what... You know, again, the satellite tag stuff that we have been doing over the years was just showing that, they do survive. They do go back to those areas that we see other species of, you know, and size classes of the turtles that we released. So, now we're kind of looking more into, you know, critical habitat. You know, where are these turtles going? What are they doing? How much time are they spending? And do we need to look at these areas in a different light? You know, should we be being more productive in that area as far as industry, or should we be making sure that we're not doing certain things in those areas?
So, that's kind of on the horizon as to why we're looking at those acoustic tags, getting that longer picture data of what's happening with these turtles, versus the, kinda that shorter timeframe that satellite tags will give.
Colleen: Right. So, Adam, you've been doing this work for a number of years. Can you tell me, what changes you and the scientific community, what you've seen with the acceleration of climate change?
Adam: Yeah. So, especially up here in the Northeast and the New England area, you know, I kind of talked a little bit about, you know, 2014 a little while ago. But, you know, our facility that we built here in Quincy, that the New England Aquarium built, we created this turtle hospital to house 40 to 60 turtles at the time, because that was about on par with what we saw on a season. In 2010, we had over 200 turtles come here. In 2012, we had broken the previous record. And then in 2014, you know, we just obliterated everything, with, over, close to 700 live turtles coming into our facility. You know, and you really can't spot a trend when you're kind of in it, until you're, you know, well within a few years of being in there. And it was around 2014, '15 when they started looking...
You know, climate folks were really looking at the Gulf of Maine and seeing this warming trend, and so, with that research, and us seeing, you know, no decrease in population of turtles coming into our facility through cold stunning, really, you kind of, you know, put that together, showing that, you know, that warming body of Gulf of Maine, which, at the time, was the fastest-warming body of water, it's still a very fast-warming body of water, really kind of allowed these turtles to enter Cape Cod Bay throughout the summer. Whereas, previous to that, they had a shorter kind of timeframe to make it into Cape Cod Bay before the cold water kind of kept them out again. So, that's really one of those big correlations that I've seen here. Again, when I first started, about 20 years ago, our numbers were small. It's, you know, teens and 20s of turtles that we would see. And it would fluctuate every year.
Certainly we had some years that were bigger, getting closer to 100 turtles, but certainly not what we see now, every year, which is, again, hundreds of turtles last year. This year we had 515 live turtles come into our facility here at the New England Aquarium. National Marine Life Center in Bourne also takes turtles in, from Wellfleet, and they've had over 100 turtles come into their facility. So, again, you know, this is the third-largest turtle stranding season on record. We've had three record seasons within the past five years. So, again, it's pretty crazy.
Colleen: And what sorts of numbers do you think we’ll see in the coming years?
Adam: Yeah. So, there is a paper that was published, two or three years ago now, that shows, you know, with the modeling and the statistical work that they did there, was showing that we're gonna be doing thousands of turtles, you know, by 2030. And that's just seven years away now. And so, yeah, I mean, the numbers will probably just continue to increase.
Colleen: And there’s another potentially dire consequence for sea turtles as the climate crisis forges ahead and that has to do with nesting and reproduction. Can you tell us about that?
Adam: Sure. Okay. Yeah. And I mean, the other piece to that, you know, up here, we don't see nesting, obviously...not yet, anyways. Who knows, 40, 50 years down the road. But, certainly, you know, these reptiles, their sex is determined by what temperature their nest is at. So, the warmer the temperature for sea turtles, the more skewed to females you will get. And certainly, the sea turtles will kind of react to that. They may nest a little bit earlier. They might go to more of those, northern or southerly spots on their beaches. So, they might shift some of their range, but, you know, their historical nesting beaches certainly are feeling the effect of the climate change as well. So, you're gonna start seeing more of a female population. But, again, it's not like it doesn't matter what temperature the beach is, you know, "If it's 100 degrees, oh it's gonna be a female." There is a finite threshold of cold and hot as to what would make a viable egg. So, we get to that point where these beaches are too warm, and you're not gonna get a female. You're gonna get a dead egg, and so you will not have any sea turtles being born. We do talk a lot about that kind of sexual determination skewing female, but there will be that tipping point where you just will not have sea turtles.
Colleen: So, Adam, give me one or two of your burning, like, you would just love to know X, you know, about one of our species of sea turtle.
Adam: I mean, my biggest question really is, so, they're kind of tied together, is one is, you know, how do they get in here? You know, again, it's all theoretical and hypothetical, and likely this is how these turtles show up in Cape Cod Bay, by this way. You know, we don't have a definitive answer on that. And the other question, too, that I have is, you know, when these turtles are in Cape Cod Bay, when it gets cold, how many get out? Like, do any of 'em get out? Or is every turtle that's in here as of October 1st destined to strand or die in Cape Cod Bay? You know, those are my two biggest questions about, you know, specifically sea turtles and the region that we're in here.
Adam: What about you?
Colleen: It's interesting. Well...
Adam: You're here a lot, so, what questions do you have?
Colleen: I know. Well, it's interesting. You know, I think of all the questions that, you know, when we occasionally have a group that will come in to tour, or when our Wellfleet Audubon folks come up to kind of tour the facility, and it seems like a lot of people wanna know how long they can stay underwater. How long they live? I mean, do we actually know how long sea turtles live?
Adam: I mean, it's very dependent upon species. But there is some debate with the Kemp's ridleys is, you know, how old do Kemp's get? Greens, loggerheads, leatherbacks, you know, those turtles are pretty well studied, and know, you know, they're living 80 to 100 maybe plus years. Whereas the Kemp's ridleys, I've heard folks say into the 30s, and some folks will say they get up to 70, maybe 80, I only see the young turtles here. So, that's one of those... Again that question of, like, there's more questions, I think, about sea turtle...like, the animals than we have answers. And I think that also has a lot to do with that whole piece of just, you know, we don't actually do the research out where they are, because they're out in the water that whole...you know, we certainly can time how long they're staying underwater at different aquariums and in areas, but being in a tank is very different than being out in the open ocean.
Colleen: Right. at the aquarium we have our sea turtles there that could not be released. And I don't know how old... Is Myrtle the oldest?
Adam: Myrtle is the oldest of the three that are in there. And, there's still some question on how old is she, because our records don't necessarily state whether she was a hatchling or an adult when we first got here, so...
Colleen: But that's also gotta be different than being in the wild. So, you know, I guess it would give you an idea. But I'm curious now, since you were mentioning that we have no data from when they hatch and they enter the water until they show up again. So now I'm curious about what they're doing out there, where they are.
Adam: Yeah, and, you know, there's a researcher, Kate Mansfield, she definitely did a big research on hatchling loggerheads, where they put tiny little satellite tags on lots of these turtles. So, they certainly have helped uncover some of that mystery on that species and those nesting areas. But still, there's still, you know, a lot to know. What are they doing, where are they going, [00:48:00.748] and is, again, so much more to know when... I'm always fascinated that this turtle that's, the Kemp's ridley, who is coming from Rancho Nuevo, Mexico or South Padre Island in Texas, rides the currents, and somehow gets off into the Gulf Stream off of New England, to get into Cape Cod Bay. Like, just boggles my mind that, you know, we're seeing most of them versus these other species that nest along the East Coast, that we don't see as many.
Colleen: A lot of interesting unanswered questions.
Adam: For sure.
Colleen: Well, Adam, thanks so much for joining me on the podcast. This is, you know, one of my favorite topics to talk about. So, it's been great having you on the show.
Adam: No, this is one of my favorite topics to talk about too. And thank you for having me. And it's awesome that, you know, love having volunteers such as yourself in, and, it's been fun.