COMPARING TWO ALTERNATIVE METHODS FOR SAMPLING SMALL CETACEANS FOR MOLECULAR ANALYSIS

During the last decade, non-destructive tissue sampling has been increasingly used to support the conservation and management of cetaceans. Biopsy sampling has permitted remote collection of small cores of skin and blubber to address questions on population size and structure, toxicological burdens, and feeding ecology for both large and small cetaceans. Concern about the possible disturbance and physical impact caused by biopsy sampling has led to the development of less-invasive methods of tissue sampling. However, the relative success of these alternative sampling approaches has not been examined. Here, we provide a direct comparison of the success and cost effectiveness of invasive and non-invasive methods for obtaining tissue samples from free-swimming bottlenose dolphins (Tursiops truncatus). Tissue sampling was conducted from June to October, 1998-2000, in the NE Bahamas. Our objective was to obtain tissue samples for use in molecular analyses from known individuals using both remote biopsy sampling and collection of dolphin feces. The two sampling methods employed in this study differ considerably with respect to the unique costs and benefits of each strategy. In addition to the nature of the sample collected and the potential uses of the sample, the study location and behavior of the study population will play an important role in determining which method can be adopted. In situations where biopsy sampling is neither desirable nor possible, alternative non-invasive methods, such as fecal sampling, can be successful. Furthermore, conducting more than one sampling method concurrently can prove useful for maximizing the number of different individuals sampled, particularly where individual behavior or encounter location restrict biopsy sampling opportunities.