OPEN ACCESS The 4th International Whale Shark Conference, 16–18 May 2016, Doha, Qatar
Cite this article as: Diamant S, Pierce SJ, Ramírez-Macías D, Heithaus MR, d’Echon AG,
d’Echon TG, Kiszka JJ. Preliminary observations on whale sharks in Nosy Be, Madagascar.
QScience Proceedings (The 4th International Whale Shark Conference) 2016:iwsc4.15
2016 Diamant, Pierce, Ramírez-
Macías, Heithaus, Guillemain
d’Echon, Guillemain d’Echon, Kiszka,
licensee HBKU Press. This is an open
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1Marine Megafauna Foundation, USA
2Whale Shark Mexico, Mexico
3Florida International University, USA
4Baleines Rand’eau, Madagascar
Preliminary observations on whale
sharks in Nosy Be, Madagascar
Stella Diamant1,*, Simon J. Pierce1, Dení Ramírez-Macías2,
Michael R. Heithaus3, Arthur Guillemain d’Echon4,
Tanguy Guillemain d’Echon4, Jeremy J. Kiszka3
The northern Mozambique Channel is a global hotspot for whale shark sightings, based on observer
records from the tuna purse-seine fleet and published literature. Nosy Be Island (NW Madagascar)
hosts a flourishing marine tourism industry based on viewing whale sharks and other species.
Following reports of declining sightings in other regional hotspots,such as Tofo in Mozambique,
it is important to establish if these declines represent a simple shi in aggregation site, or a
Data on population structure were also collected during a preliminary eld season from August to
Approximately 200 sightings were recorded by a single operator during 2015. Preliminary analysis
indicates that the majority of whale sharks sighted were males of lengths between 3 and 10 meters.
Most whale shark sightings were from October to December.
Regular whale shark sightings occur o the Nosy Be area from August to December. Limited sex and
size data suggests a juvenile male-biased aggregation where whale sharks were most commonly
observed traveling and feeding on copepods. New data will help to establish whether oceanographic
variability has resulted in a shi in abundance to Madagascar, or whether a broad-scale decline has
taken place. No species-level legislation protects whale sharks in Madagascar, and the whale shark
tourism industry is presently unregulated with regard to interactions. Further work on the population
ecology, movements and social importance of whale sharks in the country is justied and will inform
the development of eective conservation and tourism management initiatives.
Keywords: photo-identication, population ecology, Madagascar, Indian Ocean