Tuesday, November 5, 2013

Bucket list - release baby sea turtles - Visit to the Nuevo Vallarta Sea Turtle Preserve - Nayarit Mexico

Olive Ridley sea turtle - hatchling

By the 1970s the tortoise shell, sea turtle egg, and sea turtle meat trades had caused almost all species of sea turtles to be anywhere from vulnerable to endangered.  Ongoing efforts of concerned biologists, however, managed to bring their plight to the attention of the global conservation movement.  This attention gained enough momentum that all sea turtle species are now protected under the Endangered Species Act and the international CITES (Convention on International Trade in Endangered Species) agreement.  Even so, nearly 40 years later all sea turtle species remain ecologically vulnerable, threatened, or endangered.

What makes sea turtles so vulnerable?  There are a few main threats to their survival.  One is an ongoing illegal trade in sea turtle eggs, meat, and tortoise shell.  Sadly, as long as there is a market, someone somewhere will supply that demand.  Second, sea turtles often feed on jellyfishes.  Sadly, turtles are not adept at discerning between jellyfishes and floating plastic bags.  They ingest plastic that then clogs their digestive tracts and they starve to death.  Last and probably the greatest threat is that human coastal development encroaches and destroys sea turtle nesting beaches.  

Just like salmon return to the stream where they hatched to spawn, sea turtles return to the same beach where they hatched to lay their own eggs.  If those beaches are replaced by other structures - docks, piers, sea walls they have an extremely difficult time finding someplace to lay their eggs.  Also, once beachfront property is developed for recreation, increased human activities and light pollution discourage turtles from crawling up on the beach and laying their eggs.  Plus, as humans move into an area so do opportunistic predators such as raccoons, coatimundi, dogs, etc.  These predators can become skilled at locating and decimating newly laid nests.

In order to offset these challenges, many countries with sea turtle nesting beaches participate in programs where these beaches are patrolled during nesting season, eggs are collected, they are hatched under protected conditions, and hatchlings are released into the ocean in large groups.

Mexico participates in this effort.  One of the Mexican sea turtle preserves is located at Nuevo Vallarta, Nayarit, Mexico.  I was fortunate to visit there in October 2013 and learned how they work to conserve sea turtles along the southern coast of the state of Nayarit, Mexico.

This sea turtle conservation site has a web site you can visit to find additional information: Association for Mexican Environmental Unity

The protected area patrolled by biologists at this site are part of the Mexican National Commission of Natural Protected Areas (CONANP). 

I was able to visit the Nuevo Vallarta Sea Turtle Preserve that is located right on the beach about 0.8 miles up the coast from the mouth of the Nuevo Vallarta marina.  It was a memorable and fantastic visit. 




This is a hatchling Olive Ridley sea turtle making its way down the beach toward the water.

All you see if you walk along the beach and glance up toward the preserve is a wire fence that has tarps over parts of it for shade.



If you stop and look under the tarps you'll see lots of little plastic markers.  Each one indicates eggs, their species, when they were collected, and when they are expected to hatch.


Biologists place mesh-sided buckets over the eggs as their hatching dates approach.  This way the turtles can be collected and held safely after they emerge, until they can be released later the same day as a cohort.


Sometimes birds get into the enclosure, upset the buckets, and attack the baby turtles.  The turtle in this photo was pecked by a bird when we walked up to the fence.


Where do the eggs come from?  Biologists use 4-wheelers to patrol an 8-mile stretch of beach every night. When they come across a nesting turtle they note the turtle's species, collect the eggs, and bring the eggs back to the preserve.

Sometimes baby turtles escape the preserve singly or in pairs when they emerge.  The turtle in the photo below is one we saw heading out of the preserve while we were on a morning walk.  You can also see one of the egg markers up close.  We happened to visit in the middle of the main Olive Ridley turtle hatching season - though this species does nest year round on this beach.  We shadowed this little turtle all the way to the water, you know, to keep it from being stepped on my joggers, picked off by a bird, etc.




Made it to the surf zone! (below)


...and into the water...


...don't forget, they breathe air so they have to come to the surface regularly.


We would happily put the little turtle in a bucket, but there wasn't one below the sign.


Biologists collect the turtles that hatch during a given day and release them at twilight each night.  Prior to the release, biologists give presentations about turtles, turtle biology, and the purpose of the sea turtle preserve.  They actually give two talks at the same time each night.  One is given in Spanish and is mainly for Mexican children who come to the preserve to help with the release, and the other one is in English for tourists who are staying in the condos and time-shares along the beach.

This is one of the staff biologists (Irving, a biology graduate from the University of Guadalajara) at the preserve giving the English presentation.


The work the preserve does is important for the continued health of the sea turtle populations that nest on this beach.  Only 2-3 of every 1000 hatchlings survives to adulthood.  This is why it is important that as many eggs as possible be collected and protected.

The biologists at the preserve ask for a small donation, whatever you want, but 50 pesos is typical (a few dollars) from people at the presentation to help support the work at the preserve.  For this small donation visitors are invited to release a sea turtle of their own.

This is the ventral view of a baby Olive Ridley sea turtle.  The small tan spot where you might imagine a belly button would be is all that remains of the egg's yolk sac.  There is enough energy still in it to support the turtle for a few days.  If the baby turtle is not able to start feeding by then it will not survive.


These are some of the turtles that hatched in one day at the preserve.



Turtles are released early each evening.  Biologists lay ropes out along the beach and ask people to line up, up slope from the rope.  The biologists then walk along and distribute turtles to the people there.

Before you handle a turtle you need to cover your hands in sand so the oil from your skin won't come in direct contact with the turtles.

When the biologist gives the word, people let their turtles go and cheer them on as they make their way toward the water.  We were able to help with the release of about 500 hatchlings this evening.


Here are turtles moving down the beach to the water.



Not all nesting turtles are spotted, and not all eggs are relocated to the preserve.  Some of these nests are successful, and young hatch, emerge from the nest and make it to the water.  Here is a baby turtle emerging from a successful nest.  You can tell the nest is successful because the opening to the nest is small and there are no broken egg shells around it. (I still can't believe our fantastic luck in spotting this emergence.)


Many turtle nests are destroyed by animals that dig them up in search of eggs.

This nest, for example, was dug up, and, sadly, the animal that did it apparently did not eat the young turtles. These turtles were still alive when we came across the nest, but they were too premature to survive.  The lens cap in the center of this photo gives you a sense of scale.  The white things are egg shells and the dark objects are dying baby turtles.


This photo shows eggs dug up from another nest.  These eggs are at a stage sought after by small mammals.  The eggs are freshly laid, and they are still full of energy-rich yolk.


These photos show footprints of the likely culprits that dug up the nests we saw...probably raccoons or maybe coatimundis.



Many kinds of birds come in and pick through the remains of eggs after the mammals have dig up  nests and eaten their fill.


This nest was only partially excavated, and some of the eggs were undamaged, though it is highly unlikely that these eggs, now uncovered will complete development.


Sea turtle eggs are nearly spherical, with tough yet flexible shells, not oblong and brittle like chicken eggs.


Here I am with a baby Olive Ridley sea turtle we found on the upper beach about 1/2 mile south of the preserve.


This photo shows its release, along with another turtle we found and hovered over as it flapped its way down the beach.


This was a fantastic experience!  I now have a much better understanding of the work that these conservation biologists do, the challenges they face, and the successes they have.  The only thing we didn't see during our trip was a female digging her nest and laying her eggs.  Still, this was AMAZING!

"Gracias" to the hard working staff and volunteers at the Nuevo Vallarta Sea Turtle Preserve!  Keep up the good work!

2 comments:

  1. Oh my goodness!! This looked so great! My BF loves sea turtles! They are so cute what a great experience.

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  2. How cute, it´s great to see people making the effort to help the growing of these animals. There are some places on the riviera maya that offer snorkeling tours with the turtles. It´s a great way to interact with them in their habitat.

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