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.
) which is also currently being placed in the nest. Nature Seychelles is piloting this experiment with data loggers – with technical assistance from Kelonia – to gauge nest temperature. Data loggers record temperatures of nests throughout incubation. Sex determination in sea turtles is dependent on temperature, with a pivotal temperature in which equal numbers of males and females are produced. Temperatures above this pivotal number produce females and those below produce males. So data loggers help with sex ratio determination. The temperatures can also be used as indicators of the potential impact of global warming on hawksbill turtles.
Donations made here are
Jun 26th Brenton H USD 16.50