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madagascar field project


The first studies of Omura's whales in the wild

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madagascar field project


The first studies of Omura's whales in the wild

In 2013, a team of biologists led by Dr. Salvatore Cerchio made an exciting discovery off the northwest coast of Madagascar:  the first population of the rare and poorly understood Omura’s whale that could actually be studied, found off the northwest island of Nosy Be. 

Dr. Cerchio has been conducting research on cetaceans in Madagascar since 2004, and studying coastal dolphins and cetacean diversity in the Nosy Be region since 2007. The work on Omura's whales began in 2013, when Cerchio and his team started to see an unusual baleen whale during an effort to document diversity of cetacean species in the region.  At first, with only a few brief encounters, they thought it was a Bryde’s whale, a common mistake.  But then once they started to see them more frequently, they realized that this was something very special, and genetic verification confirmed that it was in fact Omura’s whale.

Since then Cerchio’s team has published the first scientific study on the ecology and behavior of the species in the journal Royal Society Open Science. 

 

Currently the work continues through an international collaboration between the New England Aquarium, the Malagasy NGO Les Baleines Ass'eau, and the Madagascar Centre National de Recherches Océanographiques (CNRO).  The 2015 field work was funded by the U.S. Marine Mammal Commission; funding is being sought for continuing research efforts.

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Field Site


Home base for Omura's whale work in Madagascar

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Field Site


Home base for Omura's whale work in Madagascar

Nosy Be is an island located on the northwest coast of Madagascar, and means literally Big (Be) Island (Nosy).  A spectacular setting, lush and green in the wet tropical belt that includes the northwest and east coast rain forests, with dramatic mountains and rocky coasts, white beaches and various small islands scattered about the region.  It is one of the few infrastructure centers in Madagascar, and a center of the tourism industry due to its beauty, accessibility and relatively modern conveniences. 

Initial work on Omura’s whales was conducted from a field base on Nosy Iranja, within the Ankivonjy MPA, and the assessment of cetacean biodiversity by Dr. Cerchio was instrumental in the planning process and boundary establishment for both the Ankivonjy and Ankarea MPAs.  In 2015 the field base was shifted to the west coast of Nosy Be on the small island of Nosy Sakatia, in order to be closer to the concentrations of Omura’s whales identified in 2013-2014.

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Field Methods


The nuts and bolts of collecting data in the field

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Field Methods


The nuts and bolts of collecting data in the field

The Madagascar Omura’s Whale Project employs a diverse set of methods to study the biology of this species in an integrative manner.

Photographic Identification (Photo-ID) – like most other cetaceans individual Omura’s whales can be identified from natural markings.  We use the dorsal fin shape, nicks and scars, the right-side blaze and the chevron on both sides.  Re-sightings of individuals across years and within seasons are used to estimated abundance of the population and define movements and ranges of individuals.

Skin Biopsy – now routine in research on both large and small cetaceans, small samples of skin are harmlessly collected with biopsy darts delivered with a crossbow or compressed air rifle.  Skin samples allow the analysis of genetic material for phylogenetics, population genetics and molecular ecology (like paternity and relatedness).  In addition we will be using for stable isotope analysis to make inferences on what the whales are feeding on.

Bioacoustics – we use boat-based and remoted bottom-mounted hydrophones to collect acoustic recordings of Omura’s whales vocalizations.  These recordings are used to learn about the species vocalization and breeding behavior, as well as define their presence throughout the study area with long-term Passive Acoustic Monitoring (PAM)

Plankton Tows and Feces Collection – we use fine nets to collect plankton in the vicinity of feeding whales, and feces from defecation plumes (more affectionately referred to as poop samples).  These samples will be used to investigate what the whale are feeding on through direct identification of collected animals and analysis of stable isotopes.