Dolphins, Porpoises, and Whales - IUCN

less porpoise that are most at risk and thus help to focus
future CSG conservation and research activities involving
this species.
Irrawaddy Dolphin
Project 23
Investigate status and establish protected
areas for pesut in Indonesia
Little research has been done on Irrawaddy dolphins,
locally known as pesut, in Indonesia. Populations there are
apparently patchily distributed in certain rivers and estuaries,
all of which are used intensively by humans. Unless
some special protection is given to these dolphins, they are
likely to disappear from Indonesia within a few decades.
Preliminary work by Indonesian scientists in the late 1970s
and early 1980s identified the lower Mahakam River and
its tributaries and associated lakes (especially Semayang
Lake) in southeastern Kalimantan as one area where pesut
were relatively common (Tas'an and Leatherwood 1984).
They are also frequently observed in Kumai Bay, central
Kalimantan (Kartasantana and Suwelo 1994). Another
possible concentration area is the vicinity of Cilacap Town
(Segara Anakan) on the south coast of central Java (A.
Priyono, pers. comm.).
Based on reports by Indonesian scientists, the threats
to Irrawaddy dolphins in the Mahakam River system are
more likely to involve habitat degradation (e.g. river traffic,
sedimentation of lakes, pollution by logging) and competition
for fishery resources, than direct killing or
bycatches (Priyono 1992). A detailed assessment of the
status of the species and the nature of threats is needed,
with a view to designating at least one area as a pesut
reserve or sanctuary. The attractiveness of such a designation
might be enhanced by the promise of supplementing
local incomes with a modest, carefully planned and
regulated tour industry.
Project 24
Investigate status and conservation of Irrawaddy dolphins
in southern Asia (including "old" Project A5)
Very little is known about the abundance and status of
Irrawaddy dolphins in southern Asia, but they were at least
formerly widely distributed in coastal waters and some
large river systems. Recent preliminary surveys in the
Mekong, Sekong, and Sesan rivers (Laos and Cambodia)
suggest that populations there are declining, possibly
rapidly, mainly because of fishery conflicts (Stacey and
Baird 1993, Baird et al. 1994). As recommended by the
IWC Scientific Committee in 1993 (IWC 1994), additional
surveys are needed to map the distribution of dolphins and
to collect quantitative data on dolphin density in the surveyed
areas. In every case a detailed description of meth­
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ods should be included in reports on survey results. As
possible, tissue samples should be collected from dolphins
that are found dead or taken as a fishery bycatch, and such
samples should be shared by investigators studying the
genetics and contaminant levels of this species.
In addition to the biological investigations, it is important
to work with fishermen and local officials to develop
sustainable and less wasteful fishing methods. Ideally, this
project would develop as a series of regional sub-projects,
each having both a scientific and a community-development
and education component. Areas identified thus far
as candidates for sub-projects are the Indochina Peninsula
and the vicinity of Chilka Lagoon on the Bay of Bengal
coast of India. Work on this species in Thai waters is
included under Project 44 (below).
Hump-backed Dolphins
Project 25
Investigate the ecology and conservation status
of hump-backed dolphins in West Africa ("old"
Project A9)
There is a hiatus in the distribution of the genus Sousa
between approximately Cameroon and False Bay in southern
Africa (Ross e< a/. 1994). The dolphins found along
the African west coast have long been recognized as a separate
species, S. teuszii. Given its limited range and its
nearshore and estuarine distribution in small groups, this
species is probably not abundant. Virtually nothing is
known about the degree of mixing between groups of
hump-backed dolphins that inhabit adjacent stretches of
coast. There may be several, or many, discrete populations.
A review is needed of the status of the species
throughout its range. A single investigator should be identified
to coordinate a collaborative study and to collate
national or regional reports. The final summary of findings
should include an evaluation of the species' status in
various countries and a list of management actions needed
to ensure its conservation.
Bottlenose Dolphins
Project 26
Assess the status of bottlenose dolphins
and identify problem areas
Because of the bottlenose dolphin's cosmopolitan distribution
and aggregate abundance, the species is not in immediate
danger of extinction (Fig. 26). However, populations
in many areas have declined, and the species has disappeared
from some parts of its historic range. A worldwide
review of bottlenose dolphins has never been done, in part
because the systematics of the genus Tursiops are uncertain.
The frequent occurrence of morphologically and eco-