Saving Paradise

Category: Marine life, Turtles | Date: Nov 16 2009 | By: savingparadise

No two individuals, even identical twins, have identical sets of fingerprints. For this reason fingerprints offer a reliable means of identification. They have played a huge role in the area of forensics providing accurate identification of criminals.

As it turns out, marks and patterns on certain marine animals are akin to human fingerprints and are unique to each individual. These marks are being put to good use, not to catch the criminals of sea world, but as a means of identification to help in conservation.

On Thursday 12 November, the Marine Conservation Society Seychelles, in collaboration with the Kelonia Marine Turtle Observatory in Reunion and Ministry of Environment organised a talk on how this form of identification is being utilsed for whale sharks and turtles. The talk, “using images to conserve endangered marine life” was delivered by David Rowat, MCSS, who is working with whale sharks in Seychelles  and Claire Jean from Kelonia working with turtles. As in humans where fingerprints develop at the embryonic stage and do not change, all indications in these marine animals are that marks are usually permanent with little change occurring over time.

According to Claire, Kelonia uses underwater photos of marine turtles head profiles for indetification. Their methodology consists of analyzing scale numbers and shape of both right and left profiles. Photos of these profiles are taken for each turtle. A database has been created to keep these photos. The matching of the new data with those in the database allows one to determine whether or not each marine turtle has been seen previously. Thanks to the participation of scuba divers and marine photographers, photos can be collected throughout the year in various sites.

Claire says photo ID can be used as an alternative or complimentary monitoring method. But she noted that current monitoring methods that use capture-mark-recapture techniques, require physical application of tags. Photo ID on the other hand is non-intrusive, less costly and less stressful. It is particularly useful in places where marine turtles cannot be caught and tagged and helps in situations where tags are lost. It also targets all turtles unlike the capture method, which mostly targets females and juveniles. It can be used in all habitats either at sea or one beaches. What it cannot be used for is measuring other parameters such as growth.

For whale sharks, researchers use photographs of the skin patterning behind the gills of each shark and any scars to distinguish between individual animals. Cutting-edge software supports rapid identification using pattern recognition and photo management tools. See whaleshark.org  for more information. David Rowat said that using this method between 2001-2009, 447 individual sharks have been identified in Seychelles. Fifty percent were re-sightings.

Picture via whalesharks.org

Both these projects rely on the contribution of pictures from people, and pictures come via tourists, scuba divers and others, allowing for public participation. They are asked to take good high resolution photos without obstruction, such as sand on turtles.  Identification however is done by trained people.The talk ended with an offer from Kelonia to conduct training for organizations involved in turtle monitoring in Seychelles.

Tags: Seychelles, Turtles, whale sharks

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Category: Cousin Island, Turtles | Date: Nov 10 2009 | By: savingparadise

It is that time of the year again and hawksbill turtles are making their annual pilgrimage to our shores to nest. The hawksbill breeds throughout Seychelles, peaking between mid-October and mid-January.  On Cousin Island, Conservation Officer Eric Blais reported an early appearance on August 8. Appearances are starting to pick up now and more turtles will arrive in November, December and January.

As numbers peak, so will monitoring. On a short visit to Cousin yesterday (9 Nov 2009), I took part in an afternoon monitoring exercise with Eric, David (Science Coordinator for Nature Seychelles), Mary (a volunteer helping with the turtle work) and Claire (from Kelonia) to see just what this means.

Cousin Island has one of the longest running monitoring programmes - started in 1972 - forming a core part of the wardens and volunteers work programs. Appearance dates and locations have to be recorded, with nesting beaches being patrolled several times a day. Metal tags with unique identification code, attached to the front flippers of each nesting turtle encountered help identify individual females returning to the beach each season.

Turtle emergences are recorded under four categories of behaviour: 1) “LAID” during which eggs were laid after digging one or more nests; 2) “Did Not Lay (DNL)” during which one or more nests were dug but no eggs laid; 3) “Half Moon (HM)”emergences during which digging did not occur although no disturbance factors were apparent; and 4) “Emergence Stopped by Obstacle (ESBO)” during which no digging occurred because the female was discouraged by obstacles on the beach.

After a short walk, we came across a female who had just begun to dig her pit. As I took covert pictures of her, my colleagues went about taking their data and doing their tagging. To my utter surprise Mary put her hand into the pit and with a counter in the other, began to tally the eggs as they came out.

A female turtle crawls out of the sea and using her front flippers drags herself up to the beach to a suitable nest site. There, she digs a pit with her front flippers and then excavates a vertical egg chamber with her hind flippers in which she lays her eggs. Eggs can be as many as 250. Mary counted 210 eggs for this one! Afterwards, the turtle used her hind legs to cover up the nest with sand and returned to sea.

It will take close to sixty days for the eggs to hatch and two or more days for the baby turtles to get to the surface. The babies will emerge as a group and - usually at or after dusk - head towards the sea attracted by the reflection of the moon on the water. But they face a number of challenges. Once hatched, babies are a favorite food for ghost crabs, birds and fish. Baby turtles could also be affected by beach lighting, which can cause them to head inland rather than out to sea. On Cousin, lights are of low wattage and screened from all nesting beaches.

As I left Cousin, I reflected on the work ahead for these hardworking people. Things will certainly get very busy soon. But thankfully, the collection of data will be increasingly efficient due to new technology and data analysis techniques that are being introduced.

Tags: Cousin Island, hawksbill turtle, monitoring

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Category: Turtles | Date: Jul 24 2009 | By: savingparadise

Two men have been arrested for possession of turtle meat and spearguns. The taking, selling or buying of turtles is illegal under the  Wild Animals and Birds Protection Act. Offences under this law carry a maximum fine of SR500,000.00 (about 36,000.00 USD) or a maximum term of two years imprisonment. Spearguns have been banned in Seychelles since the 70’s under Fisheries legislation and the Penal Code.

Read more… 

Tags: poachers, Seychelles, Turtle meat, Turtles

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Category: Cousin Island, Photo of the day, Turtles | Date: Jun 25 2009 | By: savingparadise

Sent in by Jovani Simeon, the Senior Warden on Cousin Island, this photo shows baby Hawksbill turtles coming out during the nesting season on Cousin. Nesting begins end of August and ends beginning March. 99% of all turtles that nest on Cousin are Hawksbill. We also get green turtles, but very few each year. The eggs of Hawksbill take roughly 58 days to incubate.

Tags: Cousin Island, Turtles

4 responses so far