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Whale sharks are living in all the warm oceans of our planet. Population repartition and behavior still need to be understood, as well as their movements. Example of a new feeding area for juvenile whale sharks in Madagascar was described and their movements monitored using Argos PTTs.

Whale sharks (Rhincodon typus) have been classified as “endangered”, with a decline of more than fifty percent of the population globally. As around Philippines (see Whale sharks: big friendly giants of the ocean), the question in the Western Indian Ocean is whether the population is decreasing, or only moving elsewhere.

Whale shark with Argos tag (Photo S. Pierce)
Whale shark with Argos tag (Photo S. Pierce)

Individual sharks normally swim around 10, 000 to 15, 000 km each year, so satellite telemetry technologies such as Argos are the only practical way to know where they are spending most of their time, where they go, etc. Argos tags are tethered using a ~1.5 m line to be out of water as often as possible, since the signal does not transmit through water (only sound would, and then it won’t go through the atmosphere and up to the satellite).

The small island of Nosy Be, in northwest Madagascar is a globally important hotspot for large marine species, including manta rays, sea turtles, humpback whales and even rare Omura’s whales. Whale sharks are routinely sighted off this island. Eighty-five individual sharks, all juveniles, were identified in a single season using photographs of their distinctive spot patterns, and 261 in three years in this area. Some of the sharks were present across several months.

Eight sharks were tagged in October 2016. They spent most of their time in shallow waters between 27.5-30°C around the tagging area in Nosy Be and seem to come here to feed. Half of the tagged sharks also visited a second hotspot near Pointe d’Analalava, 180 km south of Nosy Be. Five of the sharks swam over to Mayotte and the Comoros islands, and two swam right down to the southern end of Madagascar. One of those sharks then swam back to Nosy Be, a total track of 4,275 km. Three were resighted in Nosy Be in 2017 (having lost their tag)

Satellite tracks of whale sharks tagged in Nosy Be. Green squares show the Marine protected areas close to Madagascar. (Credits Madagascar Whale Shark Project/Marine Megafauna Foundation)
Satellite tracks of whale sharks tagged in Nosy Be. Green squares show the Marine protected areas close to Madagascar. (Credits Madagascar Whale Shark Project/Marine Megafauna Foundation)

 

Dedicated whale shark tourism has been developing in the area since 2011, so a code of conduct and advices on how to behave for operators proposing with shark seeing is important to ensure sustainable and safe interactions for both whale sharks and humans

Reference:

Photo: whale shark with Argos tag (Simon J. Pierce)

Stella Diamant, Christoph A. Rohner, Jeremy J. Kiszka, Arthur Guillemain d’Echon, Tanguy Guillemain d’Echon, Elina Sourisseau, Simon J. Pierce: Movements and habitat use of satellite-tagged whale sharks off western Madagascar, Endang Species Res, Vol. 36: 49–58, 2018, https://doi.org/10.3354/esr00889

The study is part of the Madagascar Whale Shark Project, a collaboration initiated in 2016 by researchers from the Marine Megafauna Foundation, Florida International University, and Mada Megafauna.

www.marinemegafauna.org (https://www.facebook.com/MarineMegafauna/) & http://www.simonjpierce.com (https://www.facebook.com/simonjpiercephotography/)

Madagascar Whale Shark Project  https://www.madagascarwhalesharks.org/

Whale shark with Argos tag (Photo S. Pierce)

12.11.2018 Animal tracking applications Whale sharks in Madagascar

Whale sharks are living in all the warm oceans of our planet. Population repartition and behavior still need to be understood, as well as their movements. Example of a new feeding area for juvenile whale sharks in Madagascar was described and their movements monitored using Argos PTTs. Whale sharks…

07.11.2018 Flash news New Argos-3 payload to launch on MetOp-C satellite in the night of November 6th – November 7th

CLS is pleased to announce that a new Argos-3 (A-DCS) payload is in orbit, as of 0h47 UTC on November 7th. This new Argos instrument, designed by the French Space Agency (CNES), is launched onboard MetOp-C, the third and final MetOp satellite of our partner, the European Organization…
female Asian Houbara

23.10.2018 EUCAW Speakers Satellite-tracking to create the demographic evidence-base for the sustainable management of hunted Asian Houbara

As Robert J. Burnside of the University of East Anglia explains in his presentation at the European User Conference on Argos Wildlife, the migratory Asian Houbara …

19.10.2018 EUCAW Speakers The revolutionary new Argos chipset from CLS and its partners

CLS and its partners have developed revolutionary new technology, an Argos chipset for uplink and downlink communication. Its small size and weight, just 7 mm x 7 mm and under 1 gram, are noteworthy. Low cost and easy to integrate, it gives Argos satellite connectivity to the…
A snowy owl (

18.10.2018 Animal tracking applications Where snowy owls are wintering?

Snowy owls are large birds living North of America and Eurasia, with white / spotted white feathers. They are migrant birds, but in an unpredictable way – they can winter as south as the American Midwest, as well as in the Artic circle.   A snowy…
Argos nanosat prototype

16.10.2018 EUCAW Speakers Argos-4 coming soon: a new momentum for the Argos system

Argos is a collaborative, international satellite system dedicated to environmental monitoring that has been flying for 40 years. Today, thanks to 6 operational satellites, it provides global coverage via its polar orbits, a unique robustness thanks to a communication protocol fitted for harsh conditions, — one of its main advantages…
hammerhead shark

16.10.2018 EUCAW Speakers Hammerhead Shark research: Knowledge from the populations in the Canary Islands

HAMMERHEAD SHARK RESEARCH is a project that studies hammerhead sharks Sphyrna spp in the Canary Islands with the aim to contribute scientific base knowledge of these species in an understudied distribution. Information of hammerheads in this distribution is limited to the presence of two species (S. lewini and S. zygaena),…

15.10.2018 EUCAW Speakers The annual cycle of German adult Ospreys (Pandion haliaetus) – studies in the breeding and wintering areas as well as during migration since 1995 by means of satellite telemetry

During 1995 – 2011 we marked 28 adult Ospreys in NE-Germany with satellite tags working up to eight years. All except three males wintered in West Africa. The migratory paths followed while in Europe seemed much straighter and more directional compared to the migratory paths followed in Africa. This pattern was…

15.10.2018 EUCAW Speakers Year-round Satellite Tracking of Amur Falcon (Falco amurensis) reveals the longest migration of any raptor species across the open sea

The title for undertaking the most arduous of all raptor migrations, belongs certainly to the Amur Falcon, which is a complete transcontinental, transequatorial, long-distance flocking migrant. The principal breeding (mainly NE China) and wintering (mainly S. Africa) ranges are separated by both 70° of latitude and longitude. Details of the…
Photo_tortue_CHAMBAULT

09.10.2018 EUCAW Speakers Combining Argos and genetics to reveal connecting paths between juvenile and adult habitats in the Atlantic green turtle

At the European User Conference on Argos Wildlife, Philippine Chambault of IFREMER presents this fascinating project of the French Research agency IPHC-CNRS. Although it is commonly assumed that female sea turtles always return to the beach they hatched, the pathways they use during the years preceding their first reproduction and…