Madagascar – Djibouti

Madagascar
24 April 2019
Azores
17 April 2019

Madagascar
Djibuti

Whale shark

The expedition is dedicated to the project: “Whale Shark Ecology“. Participants can be university students, researchers, teachers and shark enthusiasts. The study areas are located in Madagascar in Nosybe and Djibouti.
Since 2016, the CSS coordinates the research project that involves organizations and researchers from: University of Calabria, University of Siena, I.S.P.R.A. Livorno, University Federico II ° Napoli, S.Z. Anton Dorhn. In this context, it collects data relating to the identification of individual individuals, their feeding behavior, the characterization of the zooplankton populations present, the correlations between genera and families of zooplankton and eating behavior, ways of finding food, ecotoxicology.
The logistic support in Madagascar is provided by the Manta Diving of Nosy be that provides its means for sea excursions and with which the CSS has signed a scientific Technical Partnership, while in Djibouti the CSS rents the “Elegant” boat, for didactic-scientific cruises.

NEXT SHIPMENTS IN PROGRESS:

2019 NOVEMBER-DECEMBER MADAGASCAR Team complete
2020 JANUARY DJIBUTI in progress


Images




Deepening



Whale sharks (Rhincodon typus) are panoceanic planctophages that have been described for the first time by a specimen captured in the western Indian Ocean in 1828 (Smith, 1828), the filtering apparatus of R. typus is different from that of other sharks filter feeders. The whale shark is able to feed on aspiration, which can allow them to prey on more mobile organisms and therefore they are more suitable for dense aggregations of zooplankton, while the basking shark Cetorhinus maximus and Megachasma pelagios, are apparently able to feed on prey lower densities, filtering large volumes of water (Taylor et al., 1983). Whale sharks can be uniquely identified due to spots and spots on their skin, the area behind the fifth branchial fissure is particularly suitable for this purpose (Arzoumanian et al., 2005).

Two whale shark populations are known that live mainly in the Indo Pacific area and in the Atlantic Ocean, they can reach 18-20m in length and weigh tens of tons, late reaching sexual maturity. They have been the subject of intense fishing, they are currently protected by the CITES Convention which prohibits their fishing and their number has dropped dramatically in recent decades.

Gatherings of juveniles are present along the coasts of various countries such as Madagascar, Djibouti (Micarelli et al 2017) etc, while adults generally prefer to stay offshore.

Video