Dear colleagues, the article below is currently available online in the Articles in Press section of Biological Conservation: http://www.sciencedirect.com/science/journal/00063207 or <http://dx.doi.org/10.1016/j.biocon.2005.10.031>doi:10.1016/j.biocon.2005.10.031 . Alternatively, a pdf reprint is available from me. Parra, G., J., Corkeron Peter, J., Marsh, H., in press. Population sizes, site fidelity and residence patterns of Australian snubfin and Indo-Pacific humpback dolphins: Implications for conservation. Biological Conservation. Abstract Very little is known about the ecology of snubfin Orcaella heinsohni and Indo-Pacific humpback dolphins Sousa chinensis in Australian waters. We used photo-identification data collected between 1999 and 2002 in Cleveland Bay, northeast Queensland, to estimate abundance, site fidelity and residence patterns of these species in order to make recommendations for their effective conservation and management. Our abundance estimates indicate that less than a hundred individuals of each species inhabit this coastal area. Even with relatively unbiased and precise abundance estimates population trends will be extremely difficult to detect in less than three years unless changes in population size are very high (>20% p.a.). Though both species are not permanent residents in Cleveland Bay, they both used the area regularly from year to year following a model of emigration and reimmigration. Individuals of both species spend periods of days to a month or more in coastal waters of Cleveland Bay before leaving, and periods of over a month outside the study area before entering the bay again. Because of their small population sizes and movement patterns, snubfin and humpback dolphins are particularly vulnerable to local extinction. Our results illustrate that: (1) detection of population trends should not be a necessary criterion for enacting conservation measures of both species in this region, and (2) efforts to maintain viable populations of both species in Cleveland Bay must include management strategies that integrate anthropogenic activities in surrounding areas. Best regards, Guido ____________________________________ Guido J. Parra, Ph.D School of Tropical Environment Studies and Geography James Cook University Townsville Queensland 4811 Office TG-239 Phone: 61 7 47815560 Fax: 61 7 47814020 Mobile: 0437630843 e-mail:guido.parravergara@jcu.edu.au