Research

SEA TURTLE MIGRATION STUDY

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Figure-9.13. PIT tagging on juvenile hawksbill turtle at Sonadia Island: turtle scanning with BioMark PIT tag scanner, (left) and PIT microchips, Scanner and PIT Tag applicator.

9.6. SATELLITE TRACKING

Figure-8.7. Satellite tracking system illustrations (top); map showing satellite tagging locations along Cox’s Bazar coast (above); two types of satellite tag used in program SPLASH10-309A and SPOT-293A (below).

Satellite tracking conducted to study migration and foraging habitat of sea turtle nest along Bangladesh coast. Satellite tracking involves attaching on the sea turtle shell a Platform Terminal Transmitter (PTT) and getting the transmission data from ARGOS satellite. The PTT send message to satellite each time the turtle comes to the surface to breathe and the analyzed location data of the tracked turtle then sent to MLA researcher via ARGOS satellite. In SRCWP sub-project MLA attached total 13 PTT satellite tags on Olive ridley at St. Martin Island, Teknaf-Cox’s Bazar beach, Sonadia and at offshore location west of Sonadia Island. Transmitters attached on the carapace with special epoxy glue. After switch on, transmitter started transmit signal of its position to one of the six orbiting satellite (ARGOS) at a preset time interval. This transmitter helped reveal location data, SST (Sea Surface Temperature) and location depth. This data derived from ARGOS ground station are sent to MLA program account. The International Sea Turtle Society (ISTS) helped to track the turtle through its web based program STAT (Satellite Tracking & Analysis Tools) to get daily locations. We consulted with renowned experts throughout the world, and followed the documents “Blumenthal et al 2006, Broderick et  a l 2007; Godley et al 2002; Hawkes et al 2011; Rees et al 2010”.


Tagging with Passive Integrated Transponder (PIT): We also used PIT tag for species other than Olive ridley like green turtle and hawksbill. We also use BIOMARK scanners getting PIT tag data. The model is compatible with the regionally used PIT tags from other nearby countries.    Satellite Transmitter: we used brand SPOT5-293A and SPLASH10-309A, PTT, made in USA, by Wildlife Computer. Details of the PTT with specifications mentioned in Annexure-8.
Attachment Epoxy Glue: We used Powers Fasteners PUREPRO 150 (585ml), Made in Germany.
PTT Attachment Procedure: Standard procedure followed in the protocol described in Coyne 2008 for attachment of PTT on sea turtle carapace. .  
Flipper Tagging: Tagging can reveal exciting information. Marine Life Alliance initiated a sea turtle tagging program at St Martin's Island in 2000 under its sea turtle program STURCNET (Sea Turtle Conservation Network). Those were donation Kawa Zulu Natal, South Africa, by Dr. George Hughes, and a total of 65 Monel metal tags had been attached to olive ridley and green turtles, and up to January 2003, a total of 65 tags had been attached to nesting Green and Olive Ridley turtles. Those tags were allocated for the Indian Ocean tagging program under Kawa Zulu Natal, with letter series H & N (Islam, 2003). Currently, we have already produced Inconel Flipper Tags from National Bands & Tags Co. USA, with Bangladesh designated number BD0001–BD2000. So far, during the Sea turtle program under SRCWPP we have attached 231 flipper tags on Olive ridley. Mostly tags have been stuck at the rear edge of one of the front flippers. Respective data will be recorded during tagging, and the same individual will emerge later after the nesting interval. This tagging program will uncover the nesting gap, nesting site fidelity, nesting/season by species, and total population after majority installation. For tagging, we followed the techniques described by Balazs (1999). Since tagging is slightly disturbing for nesting females, it is attached after the nesting process. Tagging data are periodically analyzed by the MARK-RECAPTURE software.
MIGRATION ROUTE & FORAGING HABITAT INVESTIGATION
Satellite Tracking: we used SPOT and SPLASH, Platform Terminal Transmitter (PTT) from Wildlife Computer, USA. We used Sika Anchorfix-3 and Powers Fasteners PurePro150, Epoxy Glue to attach the Satellite tags on turtle’s carapace. These are ANGOS based tags and data retrieved from the Satellite Tracking & Analysis Tool (STAT) of seaturtle.org. The migration routes of olive ridley turtle nesting in Cox Bazar mostly along south west coast to edge of the Continental Self and through the Indian east coast towards south. One of our tracking turtle visited Indian Laksa Island travelling Arabian sea, hence we are waiting for more exciting information and data. A total 13 satellite tags have been attached unde rthe SRCWP Sub project. Most of the turtle travelled through the indian east coast and through middle Bay of Bengal.  There were record of Foraging along the coast of Sundarban, Indian coast of Orissa, south nearshore Indian, south of Sri Lanka and at Laksha island on India in Arabian Sea. Since the olive ridley are bottom feeder and also feed on the surface turtle travelled in deep water zone and they were feeding surface or pelagic animals. Ridley dive only within 500 meters accordig to research data.
Our longest tracking turtle spent 252 days. We have still 4 tags in the sea tracking but we need some time to get the routes and final trackline. So far we attcahed transmitters at Dholghata nearshor(marine location), Sonadia Island, Cox’s Bazar beach, Cepotkhali, Bainnapara, Sahporirdwip and at St. Martin island.  As we have got extra Satellite Tags from WIDECAST-USA, we will attach more satellite tags in 2017 winter and expect to get some more data. MLA also   keeping contact with Myanmar Fisheries Ministry to allow us to do tracking work to get south east area foraging and migration information. Currently no turtle travelled to  Myanmar and further beyond to Thailand or nearshore location. The bycatch risk is high during winter months therefore tracking always good in post nesting period. But internesting and nearshore foraging habitat during nesting months we did few tracking also lost 3 lags after 29-45 days.