‘It’s the circle of life!’

Nants ingonyama bagithi Baba, Sithi uhm ingonyama… (Lion King – opening scene ;)) Ok so there may be no Pride Rock or Elton John involved, but the sea turtle life cycle is very long with many different hurdles from the moment a turtle lays her eggs until her offspring can reproduce. 

So let’s start at the very beginning (a very good place to start!): the female turtle will crawl onto the beach after dark and will start the nesting process. Once she has located her desired nesting site she will start to dig her nest. Using her powerful front flippers she will start to carve out a big pit, the body pit. Once satisfied she will then use her back flippers and carve out a cylindrical egg chamber as deep as her back flippers can reach (up to a massive 1 meter – 3 ft – depth). When she can dig no further she will lay between 100-150 eggs in the chamber. On completing her laying, she will then cover the eggs with her back flippers and then will use her front flippers to cover her pit and camouflage the nest. She then returns to the sea and will continue to nest a further 3-6 times within the season, but she will never see her offspring again.                                        The eggs will remain incubating in the sand for 50-70 days before the hatchlings will emerge. Unlike you and me turtles do not have an X and Y chromosome and the sex of the hatchlings is determined by the temperature in the middle 3rd of the incubation phase. Temperatures of 28°C (82°F) or below produces all male offspring, 32°C (90°F) or above produces all female and 30°C (86°F) produces a mixed sexed clutch.                  Once they have hatched baby turtles will orientate themselves towards the ocean using the reflection of the stars and moon off the sea's surface (there are issues with development on the beaches misorientating hatchlings away from the water, but we will tackle this subject in an upcoming blog J). They will swim out as far as they can, known as the 2 hour hatchling frenzy, until they are picked up by the ocean currents. While they are in this frenzy they will not eat anything as they have their yolk sac - a packed lunch, which they have absorbed during development, sustaining them until they are out of immediate danger. They will then drift with the currents out into the open ocean where they will remain for a period of time which has not yet been identified and thus the phase is know as the 'lost years', where they hide within floating debris or Sargassum grass using it as a shelter from predators and feeding off the fish larvae, algae and plankton that are found under these habitats.                 After several years floating in their shelter, juveniles will migrate back to coastal waters when they are about the size of a dinner plate, where they adopt several specific feeding (foraging) sites. As we learnt last week, green turtles are true herbivores and will feed in the shallow lagoons, whereas the loggerheads and hawksbills will feed off-shore on coral reefs. Juveniles will not return to their natal site but reside in the areas where the currents distributed them, meaning that juveniles from distant natal areas live together until they reach adulthood.                                                                          Upon reaching adulthood, 20-25 years later, males and females will migrate thousands of miles from their foraging grounds to their natal breeding grounds. Because of the vast distances covered in travelling, adults will typically only make this voyage every 2-3 years. When they reach the breeding grounds, courtship takes place approximately one month before the before the nesting season, and can be with multiple males. Once courtship has taken place the female stored enough sperm to fertilize her clutches for the season, and when it is time she will make her way to the very same beach on which she originally hatched and will lay her nest, thus the cycle is complete.                                              And that’s the cycle in a nut shell. A staggering 20-25 years before a single female can start to reproduce. That’s a long time to try and survive for and we will touch on the threats to sea turtles in the next blog, and what’s even more astounding is we still do not know how long they can live. One of life’s little mysteries!

There’s just enough time for a quick anecdote (Anniedote – she’ll be proud of me!) if I may which highlights the massive span of time these individuals have before they can reproduce. My mum grew up for a period of time in Northern Cyprus and the turtles that she saw hatching on the beach are quite possibly some of the same turtles that I have been monitoring in my years of volunteering in Cyprus… Now that is also the circle of life! J

Until the next time folks!

Luc J

So you think you know your turtles?

 Historically the Cayman Islands had four out of the world’s seven species of turtle nesting around its coastline: the green turtle (Chelonia mydas), the loggerhead turtle (Caretta caretta), the hawksbill turtle (Eretmochelys imbricata) and the leatherback turtle (Dermochelys coriacea). Today only the first three nest on our beaches. But can you tell the difference between our three remaining species?

No? Well let us see if we can sort that out for you!

First to the stage – the green turtle (Chelonia mydas):

Length: Can grow to an average size of 1.5m (5ft)

Weight: Can weigh up to 317.5kg (700lb)

Description: Green turtles are named for the unusual green fat that resides under their carapace and are found in shallow tropical and subtropical coastal waters. They have a dorsoventrally flattened body (a body that is flattened from top to bottom like a pancake) that is covered by a tear-drop shaped carapace with a scute pattern of 4,5,4. “Scutes” are the plates on a turtle’s shell. Green turtle shells have 4 scutes along each side and 5 scutes down the middle (see the diagram below). The carapace is coloured with flecks of green, brown, white and gold which gives it a mottled effect underwater. Unlike the other three species found here, the green turtle has a small unhooked beaked head at the end of a short neck.

Diet: They feed mostly on a variety of seagrasses.

Track pattern: When females crawl on to the beach, their tracks are very large and symmetrical in pattern. This is because female green turtles move their front flippers at the same time when crawling on the beach (like swimming the breaststroke). Green turtle nests are characterized by a very large pit (hole) and mound of sand.

Hatchling ID: Hatchlings tend to be grey in colour with the same 4,5,4 scute pattern. They are distinctively identified by their white underbellies and trailing fin edges.  They tend to be about 5cm (2 inches) in length and weigh around 25g (0.05lb).

Favourite saying: “You so turtely rock dude!”

Next to take the stage is the loggerhead (Caretta caretta):

Average length: Can grow up to 1m (3ft)

Weight: Can grow up to 113kg (250lb)

Description: Loggerheads, so called for their distinctive large beaked head and thick neck, are found in temperate and tropical regions inhabiting both oceanic and near shore habitats. They have a slight heart-shaped carapace with a scute pattern of 5,5,5, which tends to be a reddish brown in colour while their neck and flippers tend to be reddish brown on top, but pale yellow underneath.

Diet: The loggerhead is predominantly carnivorous with a very powerful set of jaws used to feed on

crustaceans, whelks, and commonly conch.

Track pattern: When females come up onto the beach to nest their tracks are asymmetrical in pattern. This is because they move their front flippers alternatively, like swimming the front crawl. Loggerhead nests are small and scrappy compared to green turtle nests.

Hatchling ID: Hatchlings tend to be in dark brown to grey in colour with dark or sometimes pale yellow underbellies (in contrast to the white underbellies of green turtle hatchlings. Again they have the same 5,5,5 scute pattern as adults and they are generally around 4cm (1.5 inches) long and weigh about 20g (0.04lb).

Favourite quote: “Does this conch make my neck look big?”

And last but by no means least – the hawksbill (Eretmochelys imbricata):

Average length: Grows up to 65-90cm (25-35inches)

Weight: Can grow up to 45-70kg (100-150lb)

Description: The hawksbill is smallest turtle found nesting and residing in the Cayman Islands. They have a long elongated head that tapers down to a sharp beak point, and are found in seas associated with a healthy coral reef system. They have a distinctive shell pattern, where the carapace is dark golden brown, with streaks of orange, red and or black with overlapping scutes in a 4,5,4 pattern and serrated edge at the back of the shell.

Diet: Being associated with a healthy coral reef, hawksbills feed on coral, algae, invertebrates and their favourite, sponges.

Track pattern: When females come up onto the beach to nest they have an asymmetrical crawl pattern. It is very hard to identify the difference between loggerhead and hawksbill tracks. However, from personal observation, the hawksbill track tends to have a very distinctive tail wiggle through the entire up and downward track, and the hawksbill tends to nest in areas of vegetation. Definite species identification can be made through night-time tagging surveys or by examining hatchlings or embryos after nests hatch.

Hatchling ID: Hatchlings tend to be in dark brown to reddish brown in colour with dark brown underbellies. Again they have the same 4,5,4 scute pattern and are generally around 4-5cm (4-5 inches) long and weigh 15g (0.03lb).

Favourite quotes: “Really, another picture...fine... all I wanted was to have my lunch in peace and quiet!”

And that’s that folks! Remember these key identification points: 1) the number of scutes, 2) the head and beak shape, 3) are they eating and if so what? And finally 4) track patterns (if you are lucky enough to stumble across a turtle or turtle track on the beach).      

So why not impress your friends with your new found knowledge!

Until the next blog!

Luc :) 

As one door closes another rapidly approaches!

Hello Fellow Followers!

Firstly a very Happy New Year to you all!

Today marked the day when turtle nesting season 2014 finally came to an end after an exceptional 8 month monitoring season. The first recorded activity was back in the beginning of May with nesting carrying on until November, making it the longest nesting season on record! Typically the nesting season is between May and September while hatching typically takes place between July and November. Is this extended nesting and hatching season a reflection on what the future holds?

This year saw another successful year with over 300 nests being reported for all three islands; 216 in Grand Cayman, 72 in Little Cayman and 54 in Cayman Brac, with an average of 81% fertilization success and a 68% hatch success. It is important to point out however, that the total number of nests is not the same as the number of turtles that are nesting. Each female can lay between 3-6 nests in one season so although the number of nests is increasing and this is very encouraging to see, the total number of nesting females is still very small and our nesting populations are very much in need of protection.

So as we close the season for another year, we only have to wait another 3 months before season 2015 starts back up again. Who knows what next season will bring, but if you have made a News Year’s resolution to get out and about more, then why not think about volunteering with team. Find out more information on our website: http://www.doe.ky/marine/turtles/ or call us on our turtle hotline: 938 (NEST) - 938-6378.

These 2 baby turtles are the last to hatch from nests laid during the 2014 nesting season. DoE staff found them trapped by roots when the last nest was excavated (checked to evaluate hatch success and fertility rate). They will be released after dark on the beach where they were found and will join the 16,998 baby turtles which have already hatched on our beaches this year. We hope that one day they will be back to nest on our shores and replenish our wild sea turtle nesting population. 

Wave after wave slowly drifting!

Last week the turtle team got called out to The Reef Resort in East End to find that the manager had a 8cm Hawksbill hatching that had been washed onto the beach. From initial observations the little fellow had a small surface abrasion on the right hand side of its shell, but other than this, the hatchling was all fit and healthy. After examining the hatchling we decided that the abrasion posed no real threat to its health so advised the manager that it could be released that night.

Photos: Sara Gregson

It is hard to estimate the hatchling’s age, but we estimate it to be around 5-6 weeks old. It is uncertain where it had originated but there are a few scenarios. One possibility is that it may have hatched from another country within the Caribbean basin, or he may have hatched in Little Cayman. We have had 6 confirmed Hawksbill nests there and one coincides with the estimated age of this hatchling.

Hatchlings that survive the journey from the nest to the sea enter the water with enough yolk sac to provide them energy for 24 – 48 hours. This time is crucial for hatchlings to swim as far out to sea as fast as they can until they can shelter in patches of Sargassum or any large floating debris that they can hid within. They enter what is known as the ‘floating nursery’ where they will spend at least a year rafting in the seaweed eating bite sized prey including  molluscs, crustaceans, hydrozoans, jellyfish, fish eggs, and Sargassum. Not only is it a source of food, the Sargassum will also provide the hatchlings with cover from predators. 

After 1-2 years the juveniles will be approximately the size of dinner plates and their pelagic lifestyle will be over as they make their way to coastal areas where they will use the high productivity of shallow coastal habitats to find prey.

At approximately 20-25 years, the turtles will reach sexual maturity and make the long journey back to their original natal beach, where the life cycles starts all over again (there’s the lion king again in the background!).

The little hatchling rescued in East End would have been drifting with the currents in the open ocean when it was pushed off course and onto shore. This is a relatively common occurrence, particularly in the winter and spring. Please call us at on the Turtle Hotline 938-NEST (938-6378) if you find a baby turtle on shore. 

Until we next blog again!

Luc :)

Hello... is it me you are looking for?

Hello there trust turtle Bloggers!

Apologies on the lack of posts over the last month! Time fly's when you work with turtles! We hope to find you all well!

Our season continues to keep us busy still on all the islands here in the Cayman Islands. On Grand both our day time monitoring of beaches and night time tagging of the females continue to keep our self and our hard working volunteers on our toes. While Little Cayman and the Cayman Brac continue to have very promising numbers of nesting turtles. Although our season of 2014 is not as busy as our record breaking year last year, we still have over 200 nests across the islands to keep us preoccupied.

Below are a few pictures of our season so far from hatchlings and tagging females to intern action shots, and even the rare opportunity to have all three nesting species of hatchlings (hawksbill, loggerhead and green turtles) in one hand at one time!

Enjoy and I hope to blog again soon!
Luc :)

Little Cayman: Not so Little in the Eyes of the Turtles!

Little Cayman is 10 miles long by 1 mile wide and is one of the closest things to paradise that the Caribbean has to offer, dotted with mangroves, ponds and beautiful stretches of beach; ideal in the eyes of a turtle!

Known in the history books as one of the Turtle Islands (“Las Tortugas”), turtles have been returning to nest along Little Cayman’s beaches for millions of years. As with her sister Islands, over the past few hundred years Little Cayman has seen a reduction in her nesting turtles but things are starting to look up!

Little Cayman’s beaches are ideal for turtle nesting, with long stretches of untouched beaches protected by thick vegetation on the landward side. This means that turtles are able to nest all around the island and nesting sites here are idyllic compared to many beaches worldwide, where encroachment of nesting habitats by developments and lighting from beachfront properties threatens turtle nesting populations.

Nesting on Little Cayman started at the beginning of May and we have a total of 38 nests so far! We are now entering the next stage: our first two nests have already hatched and have been very successful.

On July 9^th our enthusiastic volunteers that walk the beaches for us were invited to our first nest excavation of season 2014. After turtle nests hatch and baby turtles make their way to the sea, DoE staff and volunteers check to evaluate the hatch success and fertility of nests. For the loggerhead nest excavated on July 9^th, out of 136 eggs, 106 hatched – an excellent success rate. Two hatchlings remained stuck in the nest and were successfully released that evening after sunset. These little hatchlings have a long journey ahead of them. For the major part of their early life little is actually known about what happens to these little guys and until they settle down on a foraging site after several years they are said to be in the ‘lost years’. Interestingly the majority of the turtles found in Cayman waters all year round would not have originated from the Cayman Islands. When hatchlings leave their nests on the beach and make it to the seas they weigh no more than 0.5oz and thus have little influence on where the waves and currents of the oceans take them. They are not strong enough to fight against currents and will drift wherever the current goes, being distributed throughout the Caribbean basin. If they make it adulthood then they will come home to nest, specifically returning to the same area of beach where they themselves hatched -- completing the circle of life! (Don’t lie, you now have the lion king stuck in your head!).

So in the eyes of the turtles, Little Cayman is and continues to be an ideal nesting habitat. And the continued success of the data collection and turtle conservation on the island would not be possible without our dedicated volunteers who give up their free time to walk the island’s beaches for us and report in any nesting activity. So I would like to say a massive keep going guys! You rock!

Thank you!

Lucy J

 

What is the Marine Turtle program all about?

"Two very small and low islands, full of tortoises, as was all the sea all about, insomuch that they looked like little rocks, for which reason these islands were called Las Tortugas."

A description taken from Christopher Columbus on his first discovering of the Cayman Islands back in 1503. The little rocks referring to the numbers of sea turtles between the two Sister Islands. Today the nesting population has declined over time, and so in 1998 the Marine turtle program was set up by the Department of the Environment (DoE). In the first year of monitoring the program recorded only 30 nests on Grand Cayman, but over the course of the program being set up the number has steadily increase, and last season we hit our record number of nests island wide, with 287 nests on Grand Cayman alone!

Total number of nests on Grand Cayman

The Cayman Islands historically had four out of the worlds' seven species of turtle nesting along their coastlines: the loggerhead turtle (Caretta caretta), the green turtle (Chelonia Mydas), the hawksbill (Eretmochelys imbricarte) and the leatherback turtle (Dermochelys coriacea). Today there are only three species nesting: the loggerhead, the green and the hawksbill turtle. Each female can lay up to 5-6 clutches in a season each with 100-150 eggs in each clutch, with an incubation period of 50-60 days. Now that’s a lot of eggs I hear you say and why then is our general turtle population low? Well this is partly because only 1 in 1000 hatchlings survive to adulthood, which takes 20-30 years to reach sexual maturity. That’s a long time to try and survive along with plenty of other anthropogenic reasons which will we leave for another blog ;) stay tuned!

So what are we doing?

The nesting season starts from the beginning of May through till September, so we are well underway with our season now! With hatching set to start mid July onward. So currently we are doing our day time monitoring program. As the season progresses we will be looking for both female activity as well as nests starting to hatch until the females finish laying and we continue to the end with nest excavations. 

What are we looking for?

The island gets split up into two and is walked twice a week. We are looking for any turtle activity, be it a simple track up and down the beach (U-turn) or an attempted nest or a true nest. We will find it and record it. The tracks are unmistakable when seen:

On the left is a green turtle track seen by the symmetric flipper marks up the beach, and to the right is a loggerhead track identified by the asymmetric movement of the flippers. Very easy to spot when walking the beach. So if any of you bloggers that live in the Islands see these tracks, we want to know about it! Please call us anytime on the turtle hotline: 938 6978 or send us an email to doe@gov.ky.

Left:a green turtle nest, Right:Loggerhead u-turn

We are also doing turtle monitoring on our sister islands. We have a a great group of volunteers on both islands who walk the beaches for us and report back to us.  I would personally like to say a massive thank you to Jennifer Mills who has helped me get the ball rolling over in Little Cayman and who has got a group of workers from the Southern Cross resort to walk a large section of beach for us! You guys rock! Equally so do all our volunteers!

So that’s enough of me waffling on for one day!

Catch you soon!

Luc J