Marine Mammals in Madagascar: Current Knowledge and Climate Change

1
Marine Mammals in Madagascar Current Knowledge
and Climate Change

• Salvatore Cerchio
• Cetacean Conservation
• And
• Research Program
• Wildlife Conservation Society
• American Museum of Natural History

2
Marine Mammal Diversity

• Pinnipeds
• 2 species (accidental)
• Sireniens
• 1 species - Dugong
• Cetaceans
• 7 Mysticetes, 3 confirmed
• 21 Odontocetes, 12 confirmed

3
MysticetesBaleen Whales

• Humpback Whale
• Southern Right Whale
• Blue Whale
• Potential overlap of 2 subspecies
• Brydes Whale, likely
• Species ID uncertain
• Fin Whale, suspected
• Minke Whale, suspected

4
MysticetesPotential Impact of Climate Change

• Perturbation of Antarctic Ecosystem
• Humpback and True Blue Whales
• Potential local effects for some species that may
  feed in Madagascar waters
• Pygmy Blue Whale
• Perturbation of migratory patterns due to
  circulation and SST changes
• All SPECULATIVE

5
OdontocetesToothed Whales and Dolphins

• Good data limited to two CCRP field sites
• Antongil Bay
• 3 species observed
• Only Bottlenose dolphin regular/resident
• Southwest (Toliara/Anakao region)
• At least 8 species observed
• At least 3 can be considered regular/resident
• Indo-Pacific humpback dolphin
• Bottlenose dolphin (inshore form / Indo-Pacific
  species?)
• Spinner dolphin
• (Spotted dolphin, Risso dolphin, Pilot whale)

6
SW Bathymetry

• Submarine Canyon
• Closest point of deep water to coast of
  Madagascar
• Presence of some deep water species
• Spotted dolphin
• (Spinner dolphin)
• Pilot whale
• Risso Dolphin
• Bottlenose dolphin (offshore form)
• Pygmy killer whale
• Near shore shallow water species
• Humpback dolphin (obligate)
• Bottlenose dolphin (inshore form)
• Spinner dolphin

7
Impacts on Coastal DolphinsHunting around
Toliara and Anakao

• Direct takes of small cetaceans in Madagsacar
  primarily on West Coastal regions, at least north
  to Mahajunga
• Best documentation in southwest
• Toliara region
• Focus of work in village of Anakoa, population of
  3000-5000
• Dolphins taken for food as well as local sale

8
Interview Data Anakao 1999(N. Andrianarivelo)
Estimated Dolphin Mortalities 1974-1999

• Species Direct Take Stranding
• Spinner Dolphin 1850-2550 900-950
• Bottlenose Dolphin 1700-1900 90-240
• Humpback Dolphin 20-70 30-35
• Unidentified dolphin 400 100
• Total 3970-4920 1130-1350

9
Anakao Recent Dolphin Take (Y. Razafindrakoto
N. Andrianarivelo)

• October 2005
• 100-200 Stenella longirostris
• Driven against reef and stranded
• Concealed from authorities
• Meat sold in villages to N and S
• Excess buried

10
OdontocetesPotential Impacts of Climate Change

• Impacts on ecosystem and prey resources
• Possibly more significant for inshore species
• Bi-directional Synergies
• Dolphin populations already depleted from hunting
  could be further stressed by CC reduction in
  prey species
• Removal of top predator complex effect on coral
  reef / coastal communities also stressed by CC
• Again SPECULATIVE

11
Gaps in Knowledge / Future Directions

• Obvious conservation concern / emergency in SW
  region
• Very little known about cetacean distribution and
  status throughout almost all other regions
• Prelim data from Nosy Be indicate potential
  healthy population of coastal species
• NEED extensive surveys and baseline data
  collection
• NEED studies targeting potential impact of
  Climate Change
• NEED work within local communities to ameliorate
  hunting pressure and promote sustainable resource
  use