A welcome sign hung in the bathroom.

My "Where Am I?" board to help residents find me when I'm needed.

In fact, my residents’ nametags that are hung on the door are an adapted version of the sea turtle craft I used during Fins and Flippers – Sea Turtle Week last July!

Recently, I was awarded the Passive Program of the Series Award as well as the campus-wide February Star Programmer of the Month Award for my educational sea turtle bulletin board that is currently hung in my hallway. This bulletin board covers interesting facts about each species, their geographic range, as well as size charts and a diagram depicting their life cycle.

My award-winning "Sea Turtles" educational bulletin board!

Most of the information I used was taken directly from the blogs that I wrote this summer about sea turtles. It was wonderful to go back and read what I learned during my research this summer.

I also had a great opportunity to partner up with another resident advisor and have a multiple-floor educational event on penguin conservation to celebrate Penguin Awareness Day, which was January 19th.

An advertisement we used to promote Penguin Awareness Day!

This program was very well attended with 35+ residents coming out to celebrate. We had a quiz game with our residents that included information about different species, including diet, range, and natural as well as man-made threats to the penguins.

Resident Ryan Butler celebrating Penguin Awareness Day at our award-winning educational program!

All of our prizes were penguin-related, and the food was loosely penguin-themed as well. This program was also recognized with an Outstanding Active Educational Award.

I intend to continue my environmental education with bulletin boards and/or bathroom posts on the difference between seals and sea lions as well as dolphins and porpoises, the main focus of my summer internship project.

I can’t wait to come back to the National Marine Life Center over spring break to see the progress on the Marine Animal hospital, as well as seeing the progress on the patients I had the opportunity to work with and those patients I haven’t met yet! Watch out Cape Cod, here I come, again!

(http://www.marinemammalscience.org)

Last week I had the opportunity to attend (for my first time) the 19th Biennial Conference on the Biology of Marine Mammals organized by the Society for Marine Mammalogy. The conference took place from November 27-Dec 2nd in beautiful downtown Tampa, FL. Kicking off the conference was an icebreaker event at the Florida Aquarium on Sunday night, which sadly, I missed due to arriving in town too late to register (I did, however, make it to the aquarium the following day on a solo expedition). I spent 3 days attending informative talks about the current research being conducted by marine mammal scientists across the globe. Originally I assumed spending 6 hours a day in lectures would grow tiresome, but at the end I was disappointed at having to leave a day early to fly back home.

The majority of the lectures I attended were about health issues in marine mammals.  Some topics included toxin exposure from harmful algal blooms, skin lesions in bottlenose dolphins, hair loss in Australian fur seals, hearing loss in harbor seals, and the neuroimmunological effects of translocating beluga whales in captivity.  There were also lectures about conservation, behavioral ecology, and new technology being used to study marine mammals. An example of new technology used in several studies was unmanned aircraft. This was used to conduct aerial surveys of marine mammal population distribution.

I attended a student affairs workshop in order to try and get a better sense of what sorts of careers are out there for recent marine biology graduates. Despite not having a masters degree or a PhD, I still found the information very useful. The workshop helped to solidify my decision to attend graduate school in the near future and what I have decided to study once I get there. I was able to meet with veterinarians and an epidemiologist during a pathology and vet medicine breakout session. While I decided that vet school it not for me, I do want to be involved in research and work dealing with marine animal health. The lectures I attended, as well as working as an intern for the National Marine Life Center made me realize that health issues are where my passion is. Health issues combine my background in marine biology, working as a veterinary assistant, and working for the NMLC.  My previous degree in sociology and environmental conservation (received prior to my degree in marine biology) is also applicable because more often than not, diseases in marine animals is a direct result of human activity. Conservation and rehabilitation go hand in hand in ensuring a healthy future for marine mammals (and sea turtles too!).

Summer Internship Opportunity

The National Marine Life Center (NMLC) is a non-profit organization dedicated to rehabilitating for release stranded sea turtles, seals, dolphins, porpoises, and small whales, and to advancing scientific knowledge and education in marine wildlife health and conservation.

2011 Intern Brie Teaches a Marine Animal Medical Mystery Program

Education Responsibilities-Interns will assist with environmental education programs, including on-site programs, off-site programs, fairs, and festivals. Interns will assist in giving public presentations to guests of NMLC and educate them on marine animals, conservation, and the NMLC. Interns will assist in the gift shop, assist with various office projects, create displays for the learning center, and help create lesson plans and activities that are aligned with the Massachusetts State Frameworks.

2011 Intern Brian Releases a Red Bellied Cooter Hatchling

Animal Care Responsibilities- Interns will be in charge of maintaining a coastal critter tank in the marine animal discovery center. They will collect and identify the coastal animals and maintain the tank’s water quality. Depending on need/case load interns will assist with the care of the NMLC rehabilitation patients including endangered red bellied cooters, diamondback terrapins & sea turtles.  Animal Care duties will include cleaning and disinfecting tanks, equipment, and environmental enrichment devices, food preparation, administering feeds, record keeping, kitchen maintenance, and water quality testing.  Interns may also assist animal care staff during medical procedures, with admission exams, and at release events.

Other Responsibilities- Each intern will take on a project which they will work on for the duration of their internship. The project must be proposed by the student and agreed upon with the NMLC staff. At the end of the internship the intern will present the project to the staff, volunteers, and members of the public. Each intern will also be assigned a weekly chore to assist with the upkeep of the facility and equipment.

Positions are unpaid, interns must have their own transportation, and housing is not provided, but NMLC will offer suggestions.

Our 2011 Summer Interns Alexa, Brie, Brian, and Brittany!

Qualifications-

-The internship is open to students who are currently enrolled in, or recently graduated from an accredited college or university.  High school students may also be considered.

-The internship is open to students who are currently enrolled in, or recently graduated from an accredited college or university.  High school students may also be considered.

-Preference will be given to students or recent graduates working towards biology, environmental studies, marine science, education, or other related fields.

-Intern should demonstrate strong written and verbal communication skills.

-Students that are adaptable, responsible, hard working, willing to learn, and have attention to detail are encouraged to apply.

-Must be able to work independently and as part of a team.

-Interns must be able to commit to at least three months; start and end dates are flexible due to school schedules.

-Interns must work a minimum of 20 hours per week.

 To Apply- Send your resume, cover letter, and one letter of reference to Kate Shaffer at kshaffer@NMLC.org or PO Box 269, Buzzards Bay, Massachusetts 02532. Applications must be received by January 20^th 2012.

Photo by Kate Shaffer.

Admittedly, I know very little about sea turtles. After starting my internship at the National Marine Life Center I decided to order a book specifically dedicated to the biology and behavior of these mysterious oceanic reptiles. One interesting fact I came across while reading was that the temperature at which the eggs are incubated determines whether or not the turtle will be male or female.Most vertebrates have sex chromosomes (XX for female and XY for male), however, sea turtles lack these chromosomes.

Females need warmer temperatures in order to develop. For example, in green turtles, temperatures need to be 88 F or above for the eggs to become females. For males to develop the temperature is around 82 F. If the temperature of incubation falls somewhere between 82 and 88 F, a mixture of the sexes develop. Heat produced by the eggs themselves can also contribute to the incubation temperature – eggs in the center of the nest become females and the eggs along the periphery become males (Spotila 2004).

If temperature affects the sex ratio of sea turtles, how might climate change impact populations in the future? Currently, sea turtle populations that nest in the southern portion of the United States are predominately female biased. It has been suggested (Hawkes 2007) that if there is even a 1 C warming of average temperatures, an even more significant bias could occur. If average warming exceeds 3 C, mortality rates of the eggs may also occur.

Climate change may also affect the nesting grounds of turtles if sea levels rise. Beaches currently being used by turtles may vanish under the sea. Ocean acidification (caused by increased CO2 levels) could potentially alter the sediment of the beaches, which may lead to inadequate conditions for incubation (Fuentes et al 2011). Sea turtles select their nesting sites based on several factors, such as low salinity, sufficient space above the hide tide line, adequate vegetation (for some species), high humidity, etc (Hawkes 2007). All of these may be affected by an increase in average global temperatures.

Future studies need to be conducted to better estimate the current sex ratios of the various sea turtle species in order to better predict how these will be affected by changes in nesting/incubation environments. Some possible ways that sea turtles may prevent extremely biased female sex ratios are by nesting earlier (cooler periods), nesting at higher latitudes (more north), changing the depth at which they bury their eggs, or changing the type of substrate they bury their eggs in (i.e. type of sand). That way more eggs will develop into males that might have otherwise been females (Fuentes 2011).

Just recently (August 18 2011), the first sea turtle nest was discovered in Delaware. Sea turtles are not known to nest that far north as well as that late in the season. They typically lay their nests on the coasts on South Carolina, Georgia and Florida. Alex Hoar, the U.S. Fish & Wildlife Service’s Northeast Endangered Species Coordinator said that, “And with global warming, events such as this may be a sign of what is to come” (Delaware Online).

Sources:

Fuentes M.M.P.B, Limpus C.J., Hamann M. 2011. Vulnerability of sea turtle nesting grounds to climate change.  Global Change Biology. 17(140-153)

Hawkes L.A., Broderick A.C., Godfre M.H, Godley B.J. 2007. Investigating the potential impacts of climate change on a marine turtle population.  Global Change Biology: 13(923-932)

Spotila, James R. 2004. Sea Turtles: A Complete Guide to Their Biology, Behavior, and Conservation. The Johns Hopkins University Press.

Sea turtle’s nest is so egg-citing:  Sea turtle lays her eggs at Cape Henlopen in what may be the first such nesting herehttp://www.delawareonline.com/article/20110819/NEWS08/108190348/Sea-turtle-s-nest-egg-citing

Kate, Alexa, Brie, Brian, and Brittany at Woodneck Beach

I came into this summer knowing relatively little about marine animals and even less about the care that they receive during rehabilitation. Luckily I was surrounded by people at NMLC who had quite a bit of experience in the field and were more than happy to share their knowledge. Every day I learned something new and interesting from the staff, volunteers, and other interns. I now know more about sea turtles than I know about myself and I will never again mistake a sea lion for a seal. The summer provided me with plenty of hands on experience as well. I have had opportunities to administer treatments to turtles, monitor seals on nearby beaches, and release fully rehabilitated animals back into the wild.

My internship has also given me the chance to educate the public on a variety of issues related to marine animal conservation and rehabilitation. Whether it was in our kids programs, Fins and Flippers and Marine Animal Mystery, or outside NMLC walls talking with interested festival-goers, there was always someone excited to learn about all the amazing things animals can do and how we care for them when they are in need. It was challenging but fun to design and implement the children’s educational programs, and it was great to see the kids enjoying and benefiting from the work that everyone at NMLC puts in. With audiences ranging from groups of preschoolers to groups of nursing home residents, the numerous tours I gave throughout the summer tested and broadened my public speaking skills. Just about every group of people that came through the doors brought a new challenge and a new opportunity to learn.

Thank you to all of the staff, volunteers, and interns who helped to make this such a great summer.

Please join us in saying goodbye and thank you to our wonderful interns Brie, Brian, Alexa & Brittany. We wish them great success in their future endeavors, and hope that their experiences at the  National Marine Life Center have been beneficial to their education and career goals. They will all be greatly missed.

Recent sightings of sharks along Chatham beaches may bring scenes from Jaws to mind. While it is the same species of shark spotted along Chatham as in the movie, these are true great white sharks and not Hollywood hyperboles. It is true that this shark can detect a single drop of blood in 25 gallons of water, which can be up to 3 miles away. What isn’t true is that sharks crave the taste of human blood. Most human attacks from great whites are what’s called “sample biting,” when the shark will let go of the person after biting realizing that human meat is not what it wants to eat. Often attacks are because of ”mistaken identity” when sharks mistakes surfers or swimmers for prey. Because shark attacks are reality, you should be familiar with precautions to avoid one. Just remember what not to do with your “ABCDE’s”!

1. Alone. Do not swim alone, and don’t go too far from shore. Often sharks attack individuals and being alone can decrease your chance of getting lifesaving assistance.
2. Blood. Do not go in the water if you are bleeding or get injured while swimming.
3. Contrast. Sharks are attracted to contrast, like shiny jewelry which can be mistaken as fish scales or high-contrast clothing which can be mistaken for counter-shading like pattern of many prey items.
4. Dusk and Dawn. Avoid swimming at dusk, dawn, and night which are active times for sharks. Sharks can see well in low visibility conditions for people.
5. Eat. Do not swim where animals which sharks eat are. Avoid areas full of bait fish, fishing activity, seals and sea lions. Dolphins and sea birds circling may also be a sign sharks feeding nearby.

Always pay attention to local beach warnings and shark sightings as well. Respecting these animals as a predator is the first step to understanding their true nature. These animals are built to eat seals, sea lions, and fish; not to eat people. Great white sharks look for prey with the highest yield of energy. Sharks are about 85% muscle, while humans are only 40%; and it takes a lot to maintain a shark’s body. Seals and sea lions are the perfect meal because of their blubber and fat which yield a lot of energy. To white sharks, people are a skinny meal not worth the energy to consume. In order to identify prey, white sharks rely on visual cues like the body outline and color. Great white sharks often attack from below, swimming vertically at the prey, and mortally wounding it by force or biting. This behavior, which also includes breaching, is quite popular in South Africa while the sharks hunt fur seals.

Sharks go where the food goes, and the sharks spotted along Chatham were around an area populated with seals. With so many seal sightings this summer, it’s no wonder the sharks are nearby. Even if you don’t see a shark in the ocean this summer, you can have your own shark experience at the National Marine Life Center! Join us for our Fins & Flippers and Marine Animal Medical Mystery. Discover “mermaid’s purses” in our Beachcombers’ Table. These “mermaid’s purses” are egg cases for different species of sharks and rays. Stop by and learn how you can help with ocean conservation to protect ocean treasures like the Great White Shark.

Harbor seal pup.

Over the past couple of weeks the National Marine Life Center’s staff and interns have been involved with monitoring a number of stranded seals around the Cape.

There are four species of seals that live on Cape Cod: the hooded seal, the harp seal, the harbor seal and the gray seal. Two of these animals are seasonal visitors: the hooded and harp seals, and the other two live here year round: the harbor and gray seals. Our seasonal seals spend part of their lives in arctic waters. For our year round seal residents, it is pupping season. This means that this is the time of year that the females are giving birth to pups. Seal pups are very independent – pups from some species only stay with the mother for 4 days! When you see a seal on the beach a number of things could be happening. Seals are only semi-aquatic, so they spend part of their time in the water and part of their time on land. The animal could be perfectly fine and independent from its mother and just looking for a warm nap in the sun. Frequently, seal mothers leave the pups on the beach for a short amount of time so they can go fishing.

Seal pups are not as experienced or accomplished swimmers as their adult mothers, and don’t have the stamina or speed to keep up with their mothers while they’re hunting. So the mothers will leave their pup on the beach while they eat and come back for them later on. When people spot a seal on the beach, it will draw a crowd. If the mother comes back to retrieve the pup and there’s a number of people on the beach, the female will probably not approach the beach until the people are gone – even one person could be enough of a deterrent to keep her away from her pup. The baby can’t live too long without the mother – a couple days without her milk, and it will starve. If the pup is still with its mother – it’s probably not old enough to hunt for itself yet.

The seal pup found on Scusset Beach.

The first time I was able to go out with our animal care technician, Kate Shaffer, to check out a seal pup was a couple weeks ago. There was a very young harbor seal pup on the beach. This animal was probably not old enough to be independent yet. The organization responsible for marine mammal stranding rescues on the Cape is IFAW – the International Fund for Animal Welfare. When an IFAW volunteer arrives on the scene, the first thing they do is set up a barrier around the animal to keep people back. The goal is 100-150 feet on all sides – but that may not always be realistic to enforce. We give the animal as much space as possible and monitor it for 24-48 hours to keep people away from it and to find out if the animal is responsive to its environment, if it’s behaving normally, and to determine if it looks emaciated or if it’s suffering from any wounds.

The seal pup enjoys a sunny day at the beach.

The best thing for someone to do when he/she sees an animal on the beach is to LEAVE IT ALONE! Unfortunately, some people we encountered that day didn’t understand that – despite our attempt to explain that. Because seals are semi-aquatic, their skin is covered in fur, and doesn’t need to stay wet like a fish or whale. It is perfectly happy warming up on the beach, nice and dry. One woman was so distraught that we weren’t keeping the seal wet that she approached the animal and poured cold water on it. All this woman accomplished in this situation was scaring the seal – and causing it to leave the beach and swim out into the ocean, thus using up some of its valuable energy. We managed to find it again – it had found a quiet spot along the rocks on the jetty.

Harbor seal pup found a quiet spot after its harassment.

From there I hung out with some nice fishermen and watched over the seal for a couple hours – while trying not to look directly at it too much or take too many pictures. I tried not to draw too much attention to it so that it wouldn’t have to deal with the stress of loud people. My plan worked a little too well, and some teenagers jumped into the water from the jetty about 200 feet away. Although they weren’t terribly close to the pup, the splash scared it enough that it started swimming again. Kate and I followed it around the jetty as far as we could before it finally lost us. We hoped that the pup’s mother would be able to find it even though it had traveled a little way from where she left it. Unfortunately, the next morning it was found again on the beach. This is a mixed bag because it’s good news that the seal survived the night, but it’s bad news that the seal was not picked up by its mother.

Brie with the grey seal juvenile.

The next time we had a seal pup call was a couple weeks later, and it was a different species – a grey seal. This seal was probably old enough to be on its own; it had just hauled out onto the rocks along the Canal and was taking a nap. The role of the volunteers (in this case, the NMLC interns) was to answer questions about the seal, and just monitor its behavior to check for any abnormalities.

Grey seal juvenile.

We sat our with the seal for a couple hours – just talking to people and watching the seal wiggle around on the rocks, it was a great day! Eventually, the animal went back into the water on its own and continued on its journey. It was a great opportunity to spend some time with the grey seal and see how it moves on land.

Brittany with the seal. We were strictly business during our shift.

So the moral of the story is to leave seals alone if you see them on the beach. Dumping water on them or putting a blanket over them is actually harassment, and will hurt the animal much more than it could help. Seals don’t need to be wet – in fact if they’re coming up on the beach, that means that they want to dry off. Putting a blanket on a seal just reduces its ability to control its body temperature, and will probably cause it to overheat. Leave the rescue work to the professionals – please call the IFAW stranding hotline (508) 743-9548 if you find a stranded marine mammal.

Please don't harass seals!

The Leatherback

Photo credit: http://www.itsnature.org/sea/other/leatherback-turtle/

The leatherback is a “super turtle” in several aspects. First, as you may have guessed, it doesn’t have a hard shell like that of other sea turtles. Its shell is different – instead of having the ribs fuse and form a bony carapace (the top part of the shell), it has a layer of rubbery skin with a fibrous cartilage layer. This cartilage layer is covered again by membrane bone – called osteoderms. These are tiny bones about the size of a dime or quarter that lock together to form the carapace. This layer is a little flexible and this adaptation allows the leatherback to dive deeply into the water – depths of more than half a mile. It also swims faster, farther, and deeper than all other sea turtles, produces the heaviest and largest eggs, and yet is a gentle giant – eating primarily jellyfish.

One amazing thing about the leatherback is its cardiovascular system, which includes a countercurrent heat exchange system in its limbs. This system allows the leatherback to conserve body heat so that it can live in a wide range of habitats that other sea turtles cannot. The arteries and veins of the leatherback are formed in a tight network in its flippers. Arteries are the blood vessels that flow from the heart into the limbs, and veins flow from the limbs back to the heart.

As the warm blood from the arteries flows past the vein, they transfer heat to the veins before the veins lose their heat to the surface of the skin. With a counter current heat exchange system, the veins don’t carry cold blood back to the heart and lower the core body temperature – when the blood gets back to the lungs and heart it is warm. If the animal is too hot – the heat transfer can be reversed by transferring heat to the arteries so that the veins are cool when they flow back to the heart, thereby lowering the core body temperature.
They also control their body heat with thick layers of fat that surround the muscle. This works as excellent insulation in cold water. In warm water, they have a network of blood vessels that allows the blood to flow past the fat to the outer edges of the skin so that heat can be easily released. This is why nesting females’ throats turn pink.

A female leatherback dispelling heat via her pink throat. Photo credit: http://www.superstock.co.uk/stock-photos-images/1990-30657.

Another adaptation that leatherbacks and a few other sea turtles have is called esophageal papillae. These prongs are made of cartilage and line the throat of the turtle, and basically grip on to the jellyfish that it’s eating and ensures that it doesn’t slip back out as the turtle uses the muscles in its throat to expel excess salt water.

Leatherback showing esophageal papillae. Photo credit: http://museumvictoria.com.au/about/mv-blog/categories/melbourne-museum/.

The esophageal papillae also protect the leatherback from the stinging cells for the jellyfish – as you can imagine, the jellyfish don’t go down without a fight, so these cartilaginous prongs keep the turtle from being injured by its prey. Now, leatherbacks travel vast distances and require a lot of energy to make these migrations possible – but jellyfish are primarily water, a little protein, some vitamins and minerals, and some fat. So – how on earth can a leatherback fuel it’s body with them? Well, they actually have an extremely long esophagus that leads from the mouth to the rear of the body, and then it loops up the side again until it reaches the stomach, which is about a quarter of the way from the front of the turtle. This long esophagus acts as a holding pouch so that the leatherback can continually digest its food – as parts of its meal leaves the stomach digested, new jellyfish are being pushed into the stomach.

I’d like to mention just a couple more interesting things about the anatomy of the leatherback. The ends of leatherback bones contain cartilage laden with blood vessels. This is unique among sea turtles, and is thought to facilitate their rapid growth by allowing access to necessary nutrients.

The Loggerhead

Loggerhead sea turtle. Photo credit: http://scubaemporium.blogspot.com/2011/04/loggerhead-sea-turtles-compass-of-sea.html.

The loggerhead is the most abundant sea turtle in the United States. I love the loggerhead because it is the quintessential “awkward turtle.” They are slower than many other species of sea turtles, and that may be due to the fact that they are the most common turtle to be seen with epibiota on their shells. They are, of course, named the loggerhead because of their wide skull. Hatchling and juvenile loggerheads are pelagic – or live in the open ocean far from any coast. They like to hang out in convergence zones where they can get access to a variety of food sources. Loggerheads are a warm water species, and are rarely seen in water lower than 50ºF. Once they reach juvenile stage, loggerheads are take on a reddish-brown shell which is characteristic of the species and will stay with them throughout their lives.

Loggerheads prefer to eat mollusks and crustaceans, in order to do this their rhamphotheca (beak) is extremely thick, and they have broad, heavy muscles in their jaws for crushing.

Loggerhead feeding on a hermit crab. Photo credit: http://www.flickr.com/photos/belizediversity/2287668884/groups/.

As you may have guessed, loggerheads are completely carnivorous. They are opportunistic feeders. They eat mostly invertebrates and insects, but their diet can also include jellyfish, medusae, salps, barnacles, snails, aquirts, anemones, sea cucumbers, marine worms and fish.

Loggerheads reach sexual maturity at 17-33 years of age. Females lay an average of 110 eggs per clutch, with usually 2-3 nests per year, although they can lay up to 7. they wait about 2 weeks between nests. Their eggs will incubate in the nest for 50-75 days, depending on how warm the sand is. Like most sea turtles, females use an alternate gait on land, meaning they move the front left flipper at the same time as the back right, and vice versa. They are documented to have high nest fidelity.

Loggerhead leaving the sea to nest. Photo credit: http://www.scistp.org/lifehistory/cycle.php.

The Green

The green sea turtle is your “poster child” sea turtle, if you will. They are the most commonly recognized species because of their beauty. Surprisingly, their shells and skin are not green as the name might imply – their coloration is more of a brown/yellow/white mixture. They are called green turtles because their fat is green. Green sea turtles are the only species in which the adults are completely herbivorous (vegetarian) and eat primarily sea grass. Green juveniles are carnivorous like other species, though, and their digestive system actually changes as they mature to allow for this dietary shift. Green turtles’ large intestines actually double in length in order to digest the plant material properly. Because of all the vegetation they eat, their FAT is actually green – which is how they got their name. They can be distinguished from other similar looking species by looking at the scales on their head. Between the eyes, they have a pair of scales where other turtles only have one or several. Their scales are well defined and dark. They are also the only species with jagged edges on their lower beak, these act as pruning shears to take bites of grass.

Green turtles play an important role in the “underwater prairies” of their feeding grounds. The role they play is similar to that of the buffalo on the open prairies in the early days of American colonization. They modify the prairies by eating so much of the excess plant material, stimulating growth in the ecosystem. They will also return to the sites that they previously grazed in order to eat the new sprouts that are full of nutrients. It’s estimated that there are only between 3-9% of green sea turtles left from their pre-human numbers. The reduction of green sea turtles can have serious repercussions for the marine grasslands they modify. The marine grasslands are very important to the ocean as a whole because they act as nurseries for many species, and it is one of the most productive ecosystems in the world.

Green sea turtle feeding on sea grass. Photo credit: http://www.flickr.com/photos/32328358@N07/page9/

Green turtles become sexually mature at between 12 and 50 years depending on where they feed and what they were able to eat. Their nesting season is between June and September, and they are noted to have high nest fidelity. In other words, they commonly return to the same beach to nest each season that they reproduce. They lay 1-7 clutches/year, and usually have 13 days between each nest.

Green turtle nesting. Photo credit: http://www.the-islander.org.ac/artd_6187_02_2009_60.html.

Green turtle females are said to be more skittish than other types of sea turtle females, and frequently have false crawls. Like the leatherback, green turtles have a unique gait as adults – moving both front limbs at the same time, then both back limbs. The hatchlings, however, use the alternate gait. Hatchlings also have the added advantage of countershading – meaning that they have dark carapaces and light colored plastrons to help camouflage them from both underwater and aerial predators.

As I mentioned in my previous blog, fibropapillomatosis is a debilitating skin disease that particularly affects green sea turtles. In fact, it’s estimated that 40-60% of green sea turtles in Florida are affected by it. However, this disease is a small problem compared to the impacts that humans are causing the species. They are still frequently hunted in some countries for their fat, meat and skin. They are used frequently in green turtle soup. Historically, green turtles actually played an import role in allowing the Spanish colonization of America. They provided a valuable food source to the colonists. Currently, loss of nesting habitat is the biggest threat in the United States.

Sea turtle swims in North Madagascar. Photo credit: http://www.allposters.com/-sp/Sea-Turtle-Swimming-Underwater-Nosy-Be-North-Madagascar-Posters_i5264967_.htm

As you may have read in my previous blog (Sea Turtles Part 1) or in Alexa’s blog (New England Aquarium Adventure), the National Marine Life Center interns took a trip to the New England Aquarium last week. While we were there, we animal nerds got our fill of marine life from all over the world. For me, of course, the sea turtles were the most exciting part! While visiting the gift shop, I obtained a wonderful book called Sea Turtles of the Atlantic and Gulf Coasts of the United States. It has really been a wonderful resource for me to deepen my understanding of sea turtles biology, behavior, and the things that threaten them in the wild. I’ve learned so much, in fact, that I’ve had to split up my sea turtle blog into several parts. This section deals with the things that threaten turtles, some of these problems are unique to sea turtles, others are quite common among marine animals throughout the ocean: disease, predators, human impacts and the conservation efforts being done to counteract these threats and save these animals.

Disease

One of the most common diseases that affect green sea turtles is fibropapillomatosis. Fibropapillomatosis is a debilitating skin disease that affects sea turtles all over the world. This skin disease causes the turtles to develop tumors on their skin. Though it most commonly affects greens, it has also been documented in loggerheads, Kemp’s ridleys, olive ridleys and leatherbacks. This disease can be fatal if it invades the turtle’s internal system, but will often heal if the tumors are superficial. Scientists also think that this could be a virus because herpes was found in 95% of all Florida cases.

Turtle showing symptoms of fibropapillomatosis. Photo credit: http://nmlc.org/wp-content/uploads/2011/07/fibropapillomatosis.png.

Internal parasites

There are a number of internal parasites found in sea turtles. Some of the most common ones include flatworms and blood flukes. In fact, 33% of loggerhead sea turtles on the east coast are found with disease-producing blood flukes.

Blood fluke. Photo credit: http://onlinesurgicaltechniciancourses.com/2010/17-disgusting-parasites-that-might-live-inside-you-right-now/

Flatworms are also frequently found in sea turtles. All species of flatworms are found in the gastrointestinal tract  except for one that has been found in the bladder. Though these flatworms are parasites, they do not necessarily seem to cause weakness to the turtle. Most wild turtles will have some kind of parasite on or within it, but until the population increases to a high number, the parasite may not be debilitating to the animal.

Roundworms are also found in the stomach or intestinal tract of sea turtles, but frequently the turtle will show no indication of a negative impact caused by these parasites.

Roundworms. Photo credit: http://wallpaperactristsbollywood.blogspot.com/2011/05/infected-with-roundworm.html.

External parasites

Some of the common external parasites found on sea turtles include leeches and a number of different species that reside on the shell called epibiota. Leeches are usually seen around where the flippers attach to the rest of the body.

Epibiota on a sea turtle shell. Photo credit: http://www.georgiaseaturtlecenter.org/kids-spot/words-to-know/.

Epibiota is found on the shell, and these organisms can include barnacles, mollusks, polychaetes, amphipods and algae. Both leeches and epibiota are found most commonly on loggerhead sea turtles. Typically, epibiota doesn’t seem to affect the sea turtle; the organisms and the turtle are in a “commensal” relationship. So, the epibiota benefit from the association, and the turtle receives no benefit or detriment from their presence. A healthy turtle can control the amount of organisms by scraping them off with its flippers. Also, as the turtle grows it sheds the scutes (or shell scales) and so some organisms will be evicted that way. However, if a turtle is sick, it may not be strong enough to control the orgasms, and the internal and external parasites will compound. If too many organisms find a home on the turtle shell it reduces the turtle’s speed and drag it down. If the turtle doesn’t scrape them off right away though, they can potentially become permanent residents. Some barnacles are actually only found on sea turtle shells!

Predators and Dangers

Eggs

Nest cavity depiction. Photo credit: http://www.turtletime.org/.

So after a mother sea turtle lays her eggs in a nest chamber on the beach, the dangers begin for the baby turtles. The eggs can be easily trampled by careless humans or other large animals traversing the beaches. If some eggs are trampled or cracked open by predators, it not only releases a scent that makes them easier to find, but can contaminate the clutch and kill far more turtles than were initially consumed. In leatherback and hawksbill nests, “false eggs” are frequently found – these are just shelled albumin. These eggs are often much smaller than eggs containing a developing embryo and are sometimes even dumbbell shaped. The function of the false eggs is currently unknown, but it must have some kind of evolutionary advantage. Some hypotheses include keeping moisture high in the nest or maybe even distracting predators.

Leatherback eggs showing false eggs. Photo credit: http://www.thesea.org/TheSea/leatherback_sea_turtles.html

When a turtle is hatching from the egg, it uses a caruncle (egg tooth), a hard appendage on the top of its beak to break through the shell.

Caruncle. Photo credit: http://www.georgiaseaturtlecenter.org/kids-spot/words-to-know/.

In order to avoid the most predators, hatchlings usually hatch at night, though this is not foolproof because there are nocturnal predators as well. The hatchlings on the top of the nest can feel if it’s time to rouse the rest of the hatchlings if the sand above the nest is cool or warm, indicating night or day. If the top turtles start digging and wiggling around in the nest, the others will follow. Usually they go about this in spurts, all digging for a while, then all resting, until finally they break through the top and are able to move together out of the nest. Those who hesitate lose the advantage of surprise, and have a less likely chance of reaching the ocean undetected. The most common predators of eggs and hatchlings include ghost crabs, sea birds, bears, raccoon, feral pigs, ants, armadillos, feral/domestic dogs and, of course, humans.

Hatchlings

Hatchlings face many of the same predators and dangers that the eggs do, plus some. In the water they face big fish, sharks and much more. Also, once sea turtles reach the ocean, they are solitary animals, though they are sometimes seen in groups because of similar migration routes. Hatchlings face human-caused dangers as well – like light pollution. Hatchlings use the brightest light source as a way to navigate back to the ocean. We think that maybe they’re looking for the moon reflecting off the waves. However, if the brightest light source isn’t the ocean, and it’s actually a street light or house, turtles will head in the wrong direction. If hatchlings are heading away from the ocean their chance of being spotted by terrestrial predators goes up significantly, they also only have a small amount of energy left from the nutrients they received from the egg, so they can starve. They can also fall into holes or gutters and become trapped.

Leatherback hatchling headed for the ocean. Photo credit: http://www.catchconservation.com/turtles/.

Juveniles/Adults

Adults and juveniles face similar dangers. Human caused issues stem frequently from pollution, bycatch, entanglement, destruction of habitat (including nesting beaches) and active harvest.

Pollution is a huge issues for turtles, specifically littering. Turtles often mistake plastic bags floating at the surface for food, and this is fatal. It can either cause an obstruction in the digestive tract, or it will make the turtle feel as though it’s full even though it’s not getting any nutrients, and it will starve to death. If fishermen do not responsibly dispose of their fishing line, turtles can easily become entangled. Fishing line may look relatively harmless, but it can easily cut into marine animals’ skin and cause deep wounds, infections, and even painful amputation. For more information on entanglement or how to properly dispose of fishing line, see my previous blog: Monofilament Recycling Program Underway.

The fishing industry also takes a toll on sea turtle numbers. Sea turtles are frequently victims of boat strikes. In fact, back home in the midwest, the Omaha Henry Doorly Zoo in Omaha, Nebraska is currently caring for a sea turtle that was hit by a boat in 2002 and deemed unreleasable. Her name is Bubbles and she is a 15-20 year old green sea turtle. For more information on this particular turtle please see: Omaha World Herald News Article or Omaha Zoo\’s press release.

Bubbles receiving a CT scan, courtesty KETV News.

Turtles are frequently caught in fishing nets as “bycatch” – this means that they were accidentally caught. Because turtles breathe air, if they get stuck in fishing nets and are unable to surface, they easily drown. Even if they somehow manage to get out in time, they often die of shock. TEDs (turtle excluder devices) became a mandatory piece of equipment for all trawlers fishing in US waters. These are a device that attaches to the net so that large objects (like sea turtles) will be released from the net without affecting the fisherman’s catch size. This is somewhat of a controversial issue. Because turtles experience shock from going through the fisherman’s nets, many of those that are freed from the nests will still die. Some say that the TEDs are greatly reducing turtle mortality, others, such as the author of my new sea turtle book, say that turtle deaths are actually increasing since use of the TEDs was implemented.

A diagram depicting how TEDs work. Photo credit: http://www.seaworld.org/infobooks/SeaTurtle/stconser.html.

Of course, there is also a continuing problem with deliberate hunting in many countries. There’s still a market for sea turtle eggs and meat, and though education around the world about the need to conserve these animals is increasing, many people still kill nesting females and harvest eggs.

In addition to human caused dangers, turtles also face natural dangers. Even adult sea turtles have a couple predators like sharks and orcas. But don’t think that turtles are by any means an easy food source: Sea turtle vs. Shark.

The last threat I want to discuss is a huge issue in Cape Cod – cold stunning. If you haven’t heard, Cape Cod is a stranding hotspot – in fact it’s the third in the world next to a place in Australia and another in New Zealand! This is due to the unique geographic feature that is the Cape Cod hook.

Turtles follow the gulf stream into the Cape Cod hook and often can't get back out.

Turtles follow the Gulf Stream up north to the Cape, and find a great foraging area here. However, when it comes time for the turtle to go south for the winter, its instincts tell it to go south, and the turtle can’t figure out that it needs to go north to escape the hook and get out into open ocean.

Because turtles are reptiles, they are ectothermic or cold-blooded. This means that their body temperature depends on the temperature of the environment around them. So, as winter approaches and the water temperature drops, so does the turtles’ body temperature. Eventually they will go into hypothermic shock, this is also called cold stunning. Their heart rates drop and they wash up on the beaches, and then they are taken to rehabilitation facilities (such as the National Marine Life Center!) where their body temperatures are warmed up very slowly (just a couple of degrees a day) until they are warm enough to be put into a tank. They are then housed until spring/early summer when they are released on the southern side of the cape toward open ocean.

YOU CAN HELP!

There are things great and small that everyone can do to help sea turtles and all wildlife.

• Donate: the NMLC needs your help to complete our hospital so we can care for our turtles that are entangled, struck by boats, or cold-stunned. Our timeline is not based on what needs to be done – but rather how we’re going to fund it!
• Volunteer: Organizations such as the NMLC and Mass Audubon Society always need help. Mass Audubon is a sea turtle rescue program. There are plenty of great wildlife programs that could use your experience/expertise in whatever field you’re in!
• Don’t litter: Obviously, please discard of your garbage and fishing line responsibly, especially your plastic bags! If you come across trash, please help by cleaning it up!
• Pass it on: teach your friends, relatives, and colleagues about the trials turtles and other marine animals face so that we can make a difference together.
• Enjoy wildlife from a distance: Your presence is stressful to the animals and your respect is much appreciated.
• Call the professionals: If you come across a wounded or stranded animal, NEVER approach a wild animal without professional assistance or permission. Sea turtles and marine mammals are protected by the federal government and these animals can carry a wide array of zoonotic diseases!

For more specific information on each turtle species, see my next blog: Sea Turtles! Part 3.