Conservation of the vaquita Phocoena sinus - The Department of ...

204 L. Rojas-Bracho, R. R. Reeves and A. Jaramillo-Legorreta
menting the refuge, the federal Ministry of Agriculture and Fisheries and the Ministry of
Environment proceeded to develop the concept of a polygon covering 1263.77 km 2 . Of that
area, 900.02 km 2 is inside the Reserve, representing somewhat less than 17% of the total
marine surface area within the Reserve boundaries. To put it in a wider perspective, the
polygon as proposed by the ministries would create a vaquita refuge occupying only 0.36%
of the total surface area of the Gulf of California – hardly a large area in global terms. It
must be said, however, that the polygon does incorporate a very large proportion of the
vaquita’s known range (see below).
The Programme for the Protection of Vaquita was published in the Mexican Federal
Register on 29 December 2005. It called for the transfer of $1 million to the state governments
of Baja California and Sonora to support implementation. Besides establishment and
enforcement of the polygon, the programme addressed some other CIRVA recommendations,
e.g. those calling for development of economically productive alternatives to gillnet
fishing, alternative fishing gear and methods, and environmental education and research
programmes.
For the following reasons, we regard this officially declared programme as an important
step towards vaquita conservation:
• It was the first measure taken by any Minister of Environment specifically to address the
vaquita’s need for protection against gillnet entanglement. As explained earlier, the actual
design and configuration of the Biosphere Reserve may have benefited other threatened
species but were ill-suited to the purpose of vaquita conservation.
• It explicitly acknowledged and attempted to implement recommendations of CIRVA and
the Joint Initiative (a coalition of non-governmental organizations; Table 4).
• It redirected the focus of concern away from trawlers and towards the artisanal gillnet fleet,
which is responsible for most vaquita mortality. Previously (from the early 2000s), the emphasis
on trawlers and their supposed role in causing vaquita by-catch had made it impossible
to establish a constructive dialogue with a major part of the fishing sector. The 2005 programme
identified the artisanal fleet using gill nets as the main risk factor and included
potential solutions involving social and economic approaches and participation by all
stakeholders.
• The strategy embodied in the programme for dealing with the polygon issue avoided the
difficulties that would come from reopening the Biosphere Reserve Decree to negotiation.
Instead, it resorted to an entirely different legal instrument: the wildlife refuge. In this way,
it managed to extend protection to at least a substantial part of the 40% of the vaquita
population estimated to be outside the Reserve boundaries at any given time.
Although it may represent progress, this 2005 programme does not represent a complete
or final solution to the vaquita bycatch problem. This would be true even if the programme
were implemented and enforced immediately and with 100% effectiveness. The need would
still exist for further bycatch reduction measures to allow the severely depleted vaquita
population to recover to a point where it is no longer at risk of extinction. Shortcomings of
the programme include the following:
• Design of the polygon. Although the Ministry had agreed in 2004 and early 2005 to
implement the polygon proposed by CIRVA without change, the final design failed to grasp
the underlying philosophy of the survey methodology (distance sampling for density and
abundance estimation). Rather than recognizing that survey sighting positions represent
moments in time (‘snapshots’) for highly mobile creatures, the ministry’s published polygon
was created simply by drawing lines to connect the sighting positions with no consideration
given to encompassing a ‘buffer’ area around them.
© 2006 The Authors. Issue compilation © 2006 Mammal Society, Mammal Review, 36, 179–216