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

1996). Even at the bottom end of this range, the mortality
would probably be unsustainable. It is generally recommended
that removals should not exceed 1–2% of the population
abundance (Wade 1998). Mortality rates may be
even higher for coastal subspecies (e.g., coastal spotted and
Central American spinner dolphins, S. a. graffmani and S. l.
centroamericana, respectively) because animals from these
populations are likely over-represented, relative to their
abundance, in the bycatch (Palacios and Gerrodette 1996).
Numerous difficulties arise in attempting to assess bycatches
in artisanal gillnet fisheries. These fisheries tend to
be widely dispersed, involve many relatively small vessels
(ranging from rafts and dugout canoes to open motorized
boats up to 10m long), and operate at subsistence or smallscale
commercial levels. Thus, any meaningful assessment
requires the cooperation of local fishermen, as well as coordination
among scientists, government officials, and nongovernmental
groups. This project aims to create a network
of scientists who work with local fishing communities to
obtain quantitative data on fishing effort and gillnet-caused
mortality of cetaceans. Ideally, these efforts should be accompanied
by abundance surveys and investigations of population
structure (stock identity). One or more workshops
may be required to standardize methods among researchers
and coordinate efforts to address the problem from a multinational
perspective.
36. Develop a conservation plan for cetaceans in
the Gulf of California (Sea of Cortés)
The Gulf of California, on the west coast of Mexico, has a
high diversity of cetaceans, including large whales such as
fin, gray, blue, Bryde’s, humpback, and sperm whales, and
at least 14 species of small cetaceans (Vidal et al. 1993). The
Critically Endangered vaquita is endemic to the upper gulf.
Fishing and whale-watching are among the valuable economic
activities that take place within the gulf. Local commercial
fisheries target anchovies, sardines, shrimp, squid,
tuna, and sharks. Sport fishing is an important element of the
tourism industry. Tens of national and foreign cruise ships
bring tourists each year to watch whales along the west coast
of the gulf between Loreto and Los Cabos. Human population
centers in the bays of Guaymas, Topolobampo, La
Paz, Cabo San Lucas and Banderas are sources of pollution
that may degrade the environment and affect the gulf’s high
marine diversity and productivity.
Because human use of the gulf and its resources is constantly
increasing and diversifying, there is clearly potential
for serious impacts on cetacean populations (e.g., Findley
and Vidal 2002). Some human activities may conflict with
one another. For example, fishery- or pollution-caused reductions
in local marine mammal populations would reduce
the area’s appeal for some tourists, leading to problems in
the tourism industry. A comprehensive, integrated management
plan for the gulf is needed to ensure that economic
development is compatible with the needs of cetaceans and
other wildlife. In support of such a plan, this project should
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include: (a) compilation and review of information on distribution,
abundance, and seasonal movements of cetaceans
at different scales of time and space; (b) efforts to describe
and quantify interactions with human activities (e.g., fisheries,
tourism, polluting industries, harbor development);
(c) recommendations for cetacean conservation related, for
example, to whale-watching, fishery bycatch, underwater
noise; and (d) development of environmental education programs
for people living along the shores of the gulf and for
seasonal visitors.
37. Assess potential impacts on cetaceans of
Mexico’s planned “Nautical Stairway” along
the coasts of Baja California and the mainland
The Mexican government has announced plans to build a
network of 22 marinas and ports, spaced at intervals of
approximately 120 nautical miles along the shores of the
Baja California peninsula and the mainland states of Sonora,
Sinaloa, Nayarit, and Jalisco. Although FONATUR
(Mexico’s national fund for the promotion of tourism) has
not yet precisely defined the project, it includes the improvement
of existing coastal cities, ports, and marinas, as
well as the construction of new ones. This development,
known as the Nautical Stairway or Steps (Escalera Naútica),
is viewed as key to the economic future of the region. A
wide variety of infrastructure projects are envisioned, including
new and improved roads, airports, airstrips, golf
courses, hotels, wharves, and restaurants. The construction
of an 84-mile land bridge to facilitate the towing of yachts
across the Baja California peninsula is a priority, as is
improvement of the road between Mexicali and San Felipe
to allow cross-border access to the Upper Gulf of California
for large boat-towing rigs, facilities to supply mariners with
fuel and other provisions, hotels, golf courses, etc. It is
anticipated that by 2014, more than 60,000 vessels will be
cruising in these waters each year, in contrast to only a few
thousand at present. The region’s large and diverse cetacean
fauna is bound to be affected by this proliferation of coastal
development, but little effort has been made to evaluate the
implications for cetaceans and other marine life (Rojas-
Bracho et al. in press).
This project involves a comprehensive assessment of the
potential impacts on cetaceans. Among other things, it requires
an inventory of the region’s cetaceans (species and
populations) and an evaluation of the present condition of
their habitat. These elements then need to be evaluated in
light of the various components of the Nautical Stairway so
that areas of potential conflict can be identified and assessed.
It is essential not only that the discrete impacts of
individual development projects be considered, but also that
the cumulative impacts of the entire development package,
as a whole, be carefully assessed well in advance of decisions
about whether and how to proceed (Moore and
Clarke 2002). Governments in the region were expected to
begin designing regulations regarding marinas, ports, and