By the Galapagos Whale Shark Project (GWSP) team
Scientists from Ecuador, Japan, New Zealand and Switzerland are in the Galapagos Islands after months of preparation and planning, for the latest GWSP field trip which embarked Thursday 13 September.
Each year, the GWSP together with partners from the Galapagos National Park, Universidad San Francisco de Quito and the Galapagos Science Center, head to the remote location of Darwin Arch, off Darwin Island, to the far north of the Galapagos Archipelago. This year we are being joined again by partners from the Marine Megafauna Foundation, (MMF) and Okinawa Churaumi Aquarium & Okinawa Churashima Research Center (OCA&OCRC).
Now in its eighth year, the GWSP aims to continue with photo identification, laser biometrics (for measuring overall size), tissue biopsies for DNA study and satellite tagging to study long distance movement and diving behaviour of individual sharks. These procedures are all important for helping to improve our understanding of these endangered gentle giants, which will allow us to conserve them more effectively.
Over 99% of the whale sharks that pass through the north of Galapagos are female. They also appear to be in an advanced stage of gestation, as whale sharks give birth to live young. This hypothesis has yet to be proved and it is the hope of this year’s fieldwork that we will obtain positive data that indicates their reproductive state. Therefore we also hope to collect blood samples for chemical/hormonal analysis and carry out ultrasound examinations to identify reproductive status. Although these two processes have been attempted previously, neither have proved successful so far in the wild.
Last year, an ultrasound was attempted on a wild whale shark, but the penetration of the device was not great enough to get through the thick skin of the whale shark. However, Dr Rui Matsumoto of the OCA&OCRC, who has been developing the prototype ultrasound device, believes that past problems have been overcome in lab testing and therefore has high hopes for this year.
All of these procedures – the ultrasound, blood draw, satellite tagging, tissue sampling, photo ID and laser bio-telemetry – must be carried out in under 45 seconds as a whale shark swims by in the blue. The currents that sweep Darwin Arch sometimes reach speeds of up to 7–8 knots, with the power of hurricane force winds on land. Add to this the fact that the whale shark swims faster than most Olympic swimmers and you might understand the challenges the team faces when carrying out this kind of science in wild, wild conditions!
We’ll update you on the results from the field trip, so watch this space!
GCT have been supporting the GWSP for a number of years thanks to our donors. If you would like to support shark research in Galapagos, then please donate today!
If you would like to find out more about how GCT are working to conserve endangered sharks in Galapagos, please head to our programme webpage.