Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN

North Island population to recover. In August 2001, the
New Zealand Minister of Fisheries created a protected area
that prohibits amateur and commercial gillnet fishing within
four nautical miles of shore along a 400km segment of the
west coast of the North Island. The boundaries of this
protected area are very close to those recommended by
Dawson et al. (2001). An observer program is also planned
for trawlers and Danish seine vessels fishing in the area
closed to gillnetting.
Remaining issues: Progress has been made in protecting
Hector’s dolphins in two areas – Banks Peninsula and the
North Island west coast. However, bycatch continues
throughout most of the species’ range. The greatest immediate
requirement for Hector’s dolphin conservation is to
reduce mortality in gillnets to sustainable levels. Additional
threats unrelated to fishing include tourist interactions and
ship-strikes in high density/sensitive habitat (e.g., Stone and
Yoshinaga 2000; Nichols et al. 2001).
The management measures described above go a long
way toward minimizing human impacts on the North Island
Hector’s dolphin population, but they will not eliminate
mortality or necessarily reduce it to sustainable levels.
There are two important gaps: (a) trawling and seining are
still allowed inside the protected areas, and (b) gillnetting is
allowed to continue inside the harbors and bays on the North
Island west coast (e.g., Kaipara, Hokianga, Kawhia).
Hector’s dolphins have been sighted in most of these latter
areas, and trawling is known to entangle Hector’s dolphins
occasionally.
Conservation recommendations: The CSG urges management
authorities to implement the following, with the
goals of reducing gillnet entanglement and other sources of
human-caused mortality to sustainable levels throughout the
species’ range, and eliminating human-caused mortality for
the North Island population so that it can recover rapidly to a
viable level:
� In areas with seriously threatened populations (e.g.,
North Island west coast) allow fishing only with
methods known not to catch Hector’s dolphins (e.g.,
replace gillnetting or trawling with line fishing) and
work toward reducing pollution, boat strikes, and
other known and potential threats.
� Increase the size of existing protected areas. In particular,
include the harbors and bays in the North
Island sanctuary and extend the offshore boundaries
of both sanctuaries.
� Implement a statistically robust observer program
throughout the species’ range, to verify whether and
when bycatch has been reduced to sustainable levels.
� Continue to monitor abundance and distribution of
Hector’s dolphins and study their movements and
population structure to assess exposure to threats and
the effectiveness of management efforts.
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6.2 Geographical populations
Irrawaddy dolphins in the Mahakam
River, Indonesia
History: The population of Irrawaddy dolphins in the
Mahakam River was recently listed as Critically
Endangered, based on surveys in 1999 and 2000 that estimated
the population of mature individuals to be fewer than
50 (Kreb 2002). Between 1995 and 2001, at least 37 dolphins
died, primarily from entanglement in gillnets, but also
from vessel collisions and illegal hunting (D. Kreb, pers.
comm.; Kreb 2000). A proposal is being promoted to build
an aquarium in the provincial capital, Tenggarong, and to
stock it with dolphins from the Mahakam. This dolphin
population is further threatened by a recent increase of large
coal-carrying ships transiting through the core area of their
distribution (D. Kreb, pers. comm.). Such boats occupy over
three-quarters of the river’s width and therefore force prey
fish into shallow areas that are seasonally inaccessible to the
dolphins. The vessels also affect dolphin movements and
often collide with the tree-lined banks, causing extensive
damage to root systems where fish lay eggs.
Management issues and conservation progress:
Irrawaddy dolphins are protected from killing and livecapture
according to Indonesian law, but monitoring and
enforcement are minimal. There is also little enforcement of
laws against destructive fishing methods (e.g., the use of
electricity and poisons) and the logging of riparian forests,
which causes sedimentation and destroys fish spawning
sites. In early 2001, a local NGO, the Conservation
Foundation for the Protection of Rare Aquatic Species of
Indonesia (Yayasan Konservasi RASI), together with conservation
authorities of the East Kalimantan government,
initiated the Pesut Mahakam Conservation Program. The
primary aims of this community-based program are to establish
effective protection for dolphins in their core habitat
and to create an informed and concerned constituency to
support dolphin conservation.
Conservation recommendations: While stressing the importance
of population monitoring and further evaluation of
threats (Project 1, Chapter 5), the CSG recommends that:
� Immediate action be taken to eliminate or drastically
reduce human-caused mortality. At a minimum, alternative
employment options for gillnet fishermen
should be promoted so that accidental killing is reduced
(IWC 2001a). Regulations that prohibit the
intentional killing of dolphins, destructive fishing
methods, and the logging of riparian forests should
also be enforced. This will require the development of
a reporting network among local villagers so that
authorities become aware of infractions in a timely
manner and can take appropriate action.
� Permanent removals for captive display facilities have
the same effect as hunting or bycatch on the dolphin