I study sea turtles. AMA!

My wife and I own/operate a small beach hotel on the southern coast of Mexico and one of the most popular activities around here is to do a baby sea turtle release. We don't like to support this as it feels as though it's more industry disguised as conservation and many of the outfits are rumored to wait until they have enough tourist to release the babies which means they won't have enough yolk left to survive the 3-day swim and that basically every turtle that's not released within a few hours of hatching will 100% die.

We prefer to only take guests to participate for the natural occurrences, basically the mass layings or the mass hatchings that happen on La Escobilla Beach 5 miles from here.

What are your thoughts on this? Is our position accurate or is hatching/releasing sea turtles out of a nursery a legit OK process that does work as long as babies are released the same day they hatch?

We never promote this baby release to guests but of course they'll often read about it online and ask. I share our stance but leave the choice up to them since we're their hosts, not their parents, haha - and when they do decide they still want to do it, we only take them to the official nursery at La Escobilla where we THINK they're doing it right.

Anyhow, I look forward to your opinion.

The opinion of myself and many of my colleagues in Florida is that any delay in releasing hatchlings results in less energy to make it offshore to find refuge in Sargassum patches. In short, they should be allowed to head into the water on their own as soon as they emerge.

The main problem with having many people on the beach witnessing this naturally is that it usually occurs in the middle of the night and people (especially people with any sort of light on them, like a cell phone) can prevent sea turtles from nesting at night and disorient hatchlings.

They don't allow you to see the hatchings at night by flashlight. It's usually in the late evening or early morning...with the early morning being the better of the two since, as you said, most of the nests hatch in the middle of the night.

But for the babies who are hatched in the nursery, if they are released within a few hours, do they stand a reasonably congruent opportunity to survive compared to those who hatch right on the beach?

Clearly the situation is more complex than this as many of the eggs brought to the nursery are done so to prevent poachers from illegally digging up the eggs and eating them - so to a point, you're releasing turtles than may never have even developed had they not been relocated to the nursery.

Also...because there is a lagoon on the opposite side of the beach, many of the babies get disoriented and go the wrong way into the lagoon. The guides tell us that unless we pick up the babies from the lagoon and cart them to the ocean they will 100% die (crocodile, bird or mammal food) and so they bring buckets so tourists can fish the babies out of the lagoon and take them to the beach...do you think there is any sort of efficacy to this strategy or is it mostly nonsense to make visitors thinking they are helping?

There are no easy answers here. Wildlife managers often have to make the determination that the "management", in this case relocating nests to a hatchery, is better than doing nothing. There are many problems introduced with hatcheries. To answer one of your questions, having so many hatchlings released in one area probably increases predation risk. There are also other issues with hatcheries such as causing harm by physically moving the eggs, increases in bacteria in the hatchery sand, differences in sand temperatures and, therefore sex ratios, etc. However, where impacts are great on the nesting beach, they can help mitigate them.

Thanks again for the response.

I am pretty sure the sex ratio for the hatchery turtles here is 100% male, 0% female or vice-versa, but I want to say the warmer temps were for the males.

This particular beach will often hatch 100,000+ babies naturally in a day, though, so I doubt four or five hundred extra from the hatchery is affecting predation risk too greatly.

Just one more question since I didn't quite get it answered:

Yes or no...should we actively discourage our guests from participating in/supporting turtle release programs or does the good overall outweigh the bad in your opinion?

I would have to know more about the situation to answer your question. Email me separately from this forum. Thanks!

I know it's definitely better to not shine any sort of light on them, but is there a light color temperature that might mitigate disorienting the hatchlings? Kind of like how blue lights disrupt melatonin production in humans so we use red filters, but for turtles.

Not so much the temperature (or Kelvin), but long wave length light. Yellow, orange or red light over 560 nm is much less disruptive and even adverse to sea turtles, particularly loggerheads. There are many published papers on this topic. This technical report from FWC summarizes the affect of light on sea turtles

Sea Turtle Conservancy, where I work, has a Lighting Project to mitigate for the impacts of the Deep Water Horizon Oil Spill. More information about it.

I've heard that rising sea temperatures (largely due to climate change) are causing large jellyfish blooms and squid populations to rise. It is also my understanding that squid and jellyfish are a significant portion of some sea turtles diets. Are sea turtles benefiting from the more abundant food sources? Has there been research on this or is it too recent of a phenomenon? I am hoping this is one of the few positive changes that may come about from global warming.

While sea turtles will eat small jellies when they are very young. Leatherbacks eat primarily jellyfish throughout their life. Whether or not jellyfish populations are indeed increasing and also having a positive influence on leatherbacks is not known.

For one, it's very hard to study leatherback populations in the ocean. They spend the majority of their time hundreds of miles from land. Second, leatherback nesting trends in the North Atlantic were increasing, but have recently flattened out or decreased on many of the most abundant nesting beaches. It's a good question, but one that is complex and researchers are probably just starting to examine.

How much has the sea turtle population increased since conservation efforts have begun? Any major spikes or decreases?

Yes! One of biggest success stories in the North Atlantic is the increase in green sea turtles, particularly in Florida. Since I started working on sea turtles over 25 years ago I have seen the nesting numbers on the best nesting beaches in Florida go from a few hundred green turtle nests per year to over ten thousand in a good year. I think most biologists would agree that the main reason for this is the protection afforded them under the US Endangered Species Act.

Mr. Herren, I’m an aspiring marine biologist. The field I would like to get in to is turtle/dolphin migration. Magnetoreception in these creatures is so interesting to me. What can you tell us about this sort of navigation that is a recent development or may not be common knowledge? Ps, any tips for someone looking to break into that field?

Some of the recent work on geomagnetic sensing is in imprinting. See this paper from Dr. Lohmann's lab, which came out 4 years ago (https://www.sciencedirect.com/science/article/pii/S0960982214016388). The hypothesis is that at some point during incubation or shortly after emergence, the turtles internal compass is able to "know" it's location by sensing the earth's geomagnetic lines.

I'd advise to go to the experts in this field and try to get in the schools where they study. As I mentioned in another post, for graduate school you need a project that is funded or is expected to be funded and, of course, good grades.

Hi, Rick. My fiancee and I just moved to the Space Coast recently and she's having an incredibly hard time finding work in her field with an MS in Ecology. She really wants to work with aquatic life, but the offerings here are much more sparse than anticipated, even for volunteer work. What actions would you recommend to an ecologist that's new to an area, with no local connections, that would improve their chances of finding a career in the field?

Thanks!

Volunteer and be flexible. It is a hard field to find paid work. Check with the companies working on ecological studies and mitigation at the Kennedy Space Center.

Hey thanks for the AMA! What can an average person do to aid in the conservation of turtles?

Reduce, reuse, recycle. Vote for elected officials who will base policies on science and will protect the world we live in for future generations.

What's your favorite sea turtle fact you like to share with people?

I have personally tagged green sea turtles on nesting beaches in Florida that return within 100 m to nest again two years later. How do they do this? The best evidence is from Dr. Ken Lohmann's lab at UNC (https://bio.unc.edu/faculty-profile/klohmann/). Sea turtles appear to have a magnetic compass of the earth and use this to migrate over long distances. Pretty amazing.

Thanks for this!

How has global warming changed the behaviour or physical characteristics of sea turtles over the last decade or so?

Their are many potentially negative consequences of global warming on sea turtles. One is the potential to skew the sex ratio. Sea turtles become male or female depending on the temperature of the sand they incubate in. Warmer temperatures produce more females while cooler temperatures produce more males. The concern is that as the temperatures rise just a few degrees, beaches will be producing almost all females. Researchers are studying this in South Florida and Australia, among other places, as we speak.

I was recently on holiday and noticed a large crowd gathered near the beach. I walked over to find that they were all watching a turtle laying her eggs about a foot away from the busy boardwalk. After we watched her shuffle around and push for about 30 minutes she seemed to give up and started heading back for the sea. Just after, a policeman showed up, asked us all to leave, and blamed us for her failure for “stressing her out”.

Is it true that our quiet presence would have bothered her that much? I still feel badly about it.

A lot depends upon the species and individual turtle. For example, when loggerheads emerge on a nesting beach, they don't nest about half the time. This occurs in natural areas too. They just decide that something is not right. Some of the main human impacts to nesting turtles include people on the beach, structures (such as seawalls and dune cross-overs) and lights.

It's not so much noise, it's movement and lights from people that bother them. Think about it. If you were a large reptile with few natural predators emerging on to a beach where you move slow and cumbersome. Any perceived threat might make you leave and come back some place else. I've seen countless people preventing turtles from nesting in person and evidence of it during morning surveys. It happens a lot in busy places like Florida.

Have you noticed any sizable affect of red tide on the sea turtle population?

Last year, strandings increased in Southwest Florida due to a large red tide event. Go to FWC's website and contact them for specifics about the effect of this event on sea turtles. My understanding is that over 500 sea turtles were affected from this event. Whether or not this affected the overall sea turtle population in Florida is unclear and more difficult to answer.

Could you share a little bit about the process of pursuing a PhD later in life and what lead you to make that choice? Best wishes to you and thank you for your work.

With any graduate degree you need monetary support and you want to work with professors you like and trust. And, of course, you want to do something you enjoy because it can be grueling. All these factors fell into place and I took the opportunity.

In some ways, it's easier because I have better study habits and time management skills. In others, it's harder because I have a family and life outside of my work. I think in the end, I enjoy learning and staying humble so that's a big reason why I did it.

Is it true that sea turtles can live to be 150 years old?

No evidence for that. The best estimates are 65-85 years, but age is hard to determine in sea turtles. We do know it takes them 20 to 40 years to mature and there have been cases of tagged females nesting on the same beaches for over 35 years.

I love all animals. But I hate--nay, despise--paper straws. Does banning/limiting plastic straws (but continuing to use plastic cups, plastic 6-pack rings, plastic boxes, plastic wrap, plastic etc etc etc) really have an impact on sea turtles?

Reducing and eliminating straws in restaurants is seen as a first step toward reducing single use plastics. Sea Turtle Conservancy has a campaign to reduce straw use in restaurants Unfortunately, all plastics can make their way into our oceans, degrade and be consumed by marine animals so it's important not to get too caught up with straws. But, it's a start.

There are many companies that sell metal reusable straws so you could try that.

Would it be feasible to tie several sea turtles together in order to make a raft and escape an island in which you have been marooned?

Sorry, but no. You'd be underwater fairly quickly. People don't breathe well underwater and can't hold their breath very long.

What's the most common medical issue you encounter in wild sea turtles? Asking as a veterinarian!

Green turtles get a tumor disease called fibropapillomatosis or FP for short. We see this more commonly in green turtles found in bays, lagoons and estuaries near land, rivers and canals so it appears to be associated with environmental factors. The incidence in these areas in Florida varies from 50-70%. It's complicated as we still don't understand the etiology and afflictions can be mild to severe. A good review can be found here (https://researchonline.jcu.edu.au/42105/1/42105%20Jones%20et%20al%202015.pdf)

Hey Rick! Hopefully this comment doesn't get buried. I did a Sea Turtle studies course in Tortuguero, CR 10 years ago. Really incredible to walk the beach and study the nesting Greens. They mentioned "The Lost Years" after the turtles hatch. With technology advancing, do you have a better idea of what happens during these years?

Young pelagic green, loggerhead and Kemp's ridley turtles associate themselves with Sargassum patches in the open ocean. Loggerheads appear to spend the longest time in this pelagic phase.

Eventually, all three species recruit back to nearshore benthic habitats after 3-10 years. Dr. Kate Mansfield at UCF has been putting small satellite transmitters on these turtles over the last 7 years or so (https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2013.3039).

I've been to sea turtle hospitals/rehabilitation centers in Florida (Gumbo Limbo being a favorite of mine). Are there figures on how rehabilitated sea turtles have fared when released back into the wild?

I'm also a zoology major with a great interest in marine bio so I love stuff like this! If I can ask another question, do you have any advice to give to someone new in the field?

There are two examples I can think of where you would know something was not right. Rehab turtles repeatedly washing up stranded a few months after release. Repeatedly catching rehab turtles in the water looking for handouts at fishing piers (or something similar). To my knowledge this has not happened in Florida, at least not consistently.

As I said in another thread, volunteer and work your way into a paid job by working hard. It's often who you know.

What’s the largest turtle you ever seen? Weight and length/width?

Are turtles really technically dinosaurs?

The largest sea turtles are leatherbacks. The biggest ones can weigh over 907 kg (2,000 pounds). The largest I've seen on the nesting beach were about 590 kg (1,300 pounds) with a curved carapace length (that's the top part of the shell) at 165 cm (5.4 feet). The width of these animals is usually about a meter. They are very big.

Turtles were around during the time of the dinosaurs in essentially the same form they are today, but are considered a separate lineage of reptile evolution.

What are the "lost years" I've heard that term a lot?

Those are the years young sea turtles spend in the open ocean. They are only 'lost' because they are not easily found over the vast expanse of ocean. Floating Sargassum is important for them in this life stage so they are associating themselves with certain habitats.

Has banning plastic straws helped anything?

I don't believe we can ban all plastics. But we can reduce our use of single use plastics like straws. If all the restaurants that used plastic straws stopped using them, that would be a big change. Plastic straws are already small enough to work their way into the guts of marine animals. Plastic bottle caps are also an example of this.

Hi! Simple question, but what is your day-to-day like? I've always wondered about the daily work schedule of a biologist!

It varies a lot depending on the specific work and time of year. I'm usually on a computer writing, analyzing, emailing, coordinating, in meetings and inputing data part of the time and at other times I'm traveling, out on a boat, diving in the water, tagging turtles, recording data and doing lot's more the other part of the time. Never a dull moment.

Are turtle eggs very easy to break?

Not really. Sea turtle eggs, like many other reptilian eggs, contain more protein than calcium so they are not brittle like bird eggs. They are somewhat flexible. When they are laying, females drop eggs into their nest chamber at heights of 2 to 3 feet. If they were easy to break they would not survive long.

On vacation in Hawaii I was told that the sea turtles have made a big comeback, and they may allow families to hunt and kill sea turtles again (one turtle per family). Is there any validity to this?

Have protections of sea turtles led to them becoming an outsized population that may put other populations at risk?

Yes. The Hawaiian green turtle population has increased over the last 40 years due to conservation efforts.

As to whether native Hawaiians should be allowed to hunt them again is incredibly controversial. It's very important to remember that sea turtles are tied to the land. The nesting beaches of the Hawaiian green are in the NW Hawaiian islands, which are disappearing due to sea level rise. They may not have any viable nesting beaches 50 years from now.

a long time ago, I kicked a sea turtle egg thinking it was a golf ball on the beach. we found and opened nest near by with exposed eggs. my dad called the number on the nest warning sign and they said to put the cracked egg back in the nest and cover with sand and they might survive.

what are they odds my kicked egg made it? what are the odds that the dug up nest survived? what are the odds that it was an animal and not a shitty human that exposed the nest in the first place?

Likely the egg/embryo was already dead. Many nests get washed over and exposed by storm surf every nesting season. Predators also expose eggs, but in that case many of them would be ripped up and thrown about. And, of course, there would be evidence of digging and prints. If you found an exposed clutch with intact eggs, you can tell if they are viable by the whiteness of the eggshell. If the eggs were slightly off color, they were probably already dead. If, however, you find a recently exposed clutch with very white eggs, reburying them might just help them survive.

Exposed sea turtle eggs do not survive for long. Temperatures on the beach are too warm and they are no longer surrounded by the protection of the sand.

My sister is incredibly interested in Marine Biology, specifically starfish. She suffers from a lack of clear direction though, and seems more interested in living a certain life than in making the hard choices necessary to get into the field.

So what kind of education could she begin pursuing to get to a point where she actually gets to work with the animals, study them in their natural habitat, etc? Does she need a Marine Biology undergrad degree, or could she get a Biology undergrad and move on to a Marine Biology master's? Does she need to get her degrees from more "prestigious" schools, or could she get into the industry by attending cheaper schools that offer these programs but aren't as well known in the industry?

Basically: what is the path of least resistance that she could realistically take to get to the point where she's working with some entity to go study marine life in the field? I'd love to send her some ideas that an actual researcher in her desired field believe are realistic for her to achieve her dreams and stop spinning her wheels.

Focus, passion and hard work. She would need to go to a University and study biology. Volunteer her time with an organization that does research or conservation. And, then move on to a graduate degree, either Masters and/or PhD. It's an incredibly rewarding career, but one that demands sacrifices and hard work.

It's a career for people who want to make a positive difference in the world and, for me, that's what makes it worthwhile.

well then you're the guy to ask. is it true? is it turtles all the way down?

Only if your name is Yertle.