Jefferson, T.A.

Van Waerebeek, K.

Open Marine Archive

Conservation of Humpback Dolphins
One of only two endemic dolphin species from
western Africa, the Atlantic humpback dolphin
(Sousa teuszii), is one of two or, more likely, three
coastal species of humpback dolphins in the
genus Sousa. It is a mid-sized species distributed
in tropical and subtropical waters from the
Western Sahara south to southern Angola. Its
habitat is predominantly nearshore and estuarine,
but it does not appear to live in fresh water. The
species was discovered in Cameroon in 1892,
never to be found there again since. Nowadays, 10
range states are known in West Africa.
While historically the Atlantic humpback dolphin
may have been distributed nearly continuously
along West African coasts,
gaps are now apparent.
Monitoring of dolphin cap-
tures in artisanal ﬁsheries
off Ghana showed the pres-
ence of some 15 species of
small cetaceans, but not a
single humpback dolphin.
Despite exploratory boat
trips, the species was also not encountered off
Benin. Either it never occurred in this part of the
Gulf of Guinea or, more likely, it has become local-
ly extinct or very rare, due to human pressure.
A recent review provisionally named eight hypo-
thetical ‘stocks’ for conservation and management
purposes. While some may coincide with a bio-
logical population if indications of reproductive
isolation are conﬁrmed, other stocks may be arte-
facts, resulting from poor sampling. Atlantic
humpback dolphins do not seem to migrate or
otherwise move seasonally. However, some stocks
straddle two or more nations and regular, perhaps
daily, border crossings may occur. Technically
speaking this qualiﬁes the dolphin as a ‘migratory
species’ under the Convention for the Conser-
vation of Migratory Species. 
Information on natural history and ecology is
scarce. Some stocks are clearly small, although no
actual abundance estimates are available. The
northernmost (Dahkla Bay) stock, it is guessed,
may number less than one hundred while the
Guinea-Bissau population, possibly one of the
healthiest, could number in the high hundreds.
Surely many more Atlantic humpback dolphins
die entangled in gillnets than the few recorded
captures so far suggest. If unmitigated, this mor-
tality, along with rapid coastal habitat degrada-
tion, may threaten the long-term survival of this
enigmatic African mammal. Increased research
and conservation efforts are needed to address
these concerns, while actively involving local
scientists and managers.
The Indo-Paciﬁc species, Sousa chinensis and S.
plumbea, are not in such a precarious position.
Dolphins under Threat
The species was discovered in
Cameroon in 1892, never to be
found there again
6
Species 41: January–June 2004 
Between them, they
occupy a vast range
(from South Africa east
to central China and
northern Australia),
and collectively may
number several tens
of thousands of indi-
viduals. A single pop-
ulation in Hong Kong
and the Pearl River
Estuary numbers well
over 1,400. Despite
this, these animals are
still threatened to some
extent. They occur in
coastal waters, in some of the most degraded and
heavily populated parts of the earth. They appear
to be particularly vulnerable to problems of habi-
tat loss and degradation, and we suspect they are
being negatively affected by myriad forms of
environmental pollution.
A special issue of the journal Aquatic Mammals
highlights the status and conservation of hump-
back dolphins throughout their range. The volume
is comprised of 16 papers, and includes status
reports on regions of major study. Copies of the
special issue are available in paper or CD-Rom
format from the editor, Jeanette Thomas, at 
J-Thomas@wiu.edu.
Koen Van Waerebeek and Thomas A. Jefferson,
Cetacean Specialist Group 
Global Tree and Sustainable Use
– A Cooperative Approach
In keeping with IUCN’s attempts to adopt a more
integrated approach across its programmes, the
Global Tree Specialist Group (GTSG) and the
Sustainable Use Specialist Group (SUSG) have
formed a new partnership. 
With both Chairs Sara Oldﬁeld (Global Tree), and
Jon Hutton (Sustainable Use) based at Fauna
and Flora International in Cambridge, UK, this is
a convenient partnership. Perhaps more impor-
tant than the geographical similarity, is the
substantial overlap between the interests and
activities of the Groups, and each stands to beneﬁt
signiﬁcantly from interaction with the other. 
The GTSC has over 70 expert members, from
botanic gardens, herbaria, universities and both
governmental and non-governmental organisa-
tions, who contribute to the main aims of the
Group. These include promotion and implemen-
tation of global Red Listing for trees and acting in
an advisory capacity to the Fauna and Flora Inter
national/UNEP-World Conservation Monitoring
Centre Global Trees Campaign. The campaign
focuses on trees as ﬂagship species for conserva-
Atlantic humpback dolphin


Dolphins under threat. Conservation of humpback dolphins

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