In August 2008 a workshop was convened in Apia, Samoa by the IUCN Cetacean Specialist Group to develop protocols for assessing populations of dolphins around islands, with a focus on Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Solomon Islands. Since 2003, bottlenose dolphins in the Solomon Islands have been collected and exported to Mexico, Dubai, and Singapore, leading to concern about the potential conservation implications of such removals in the apparent absence of adequate assessment of populations prior to collection. The IUCN Global Plan of Action for the Conservation of Cetaceans considers it a general principle that small cetaceans should not be captured or removed from a wild population unless that specific population has been assessed, and it has been determined that a certain level of removals can be allowed without reducing the population’s long-term viability and without compromising its role in the ecosystem. A principal goal of the workshop in Samoa was to elaborate on the elements of an assessment that would meet such a standard. The meeting focused on scientific and technical issues relating to the conservation of populations of small cetaceans, especially Indo-Pacific bottlenose dolphins, with the expectation that the assessment framework developed by the workshop would be useful not just for the case of Indo-Pacific bottlenose dolphins in the Solomon Islands, but also for other populations of small cetaceans elsewhere.
        In preparation for the workshop, CZS conservation biologist and head of the IUCN Conservation Breeding Specialist Group Bob Lacy and I performed analyses of the potential consequences of removals from bottlenose dolphin populations, using the computer simulation program Vortex, developed by Dr. Lacy. We examined scenarios for Sarasota Bay dolphins, for which much of the requisite data on population dynamics and life history is well known. We then incorporated data from Indo-Pacific bottlenose dolphins, replacing parameters with data from this less-well-known species when possible. The results of our population viability analyses suggested that, in general, populations need to be more than 50-65 times as large as the number of animals that will be removed. Given information presented at the workshop, such a risk-averse approach likely would not have permitted removals on the scale of those that have been done to date, or which are planned.
        A report from the workshop is expected to be released in early 2009, and will be available through the IUCN.

Vortex simulation for a population of 1,000 bottlenose dolphins, with an initial population growth rate of 2.4%, comparable to Sarasota Bay dolphins with current rates of human interaction plus a removal rate of 12 females/year. Most scenarios among the 100 interations resulted in population decline, with an average potential population growth rate of -0.023.