| Individual-Based Model Framework to Assess Population Consequences of Polychlorinated Biphenyl Exposure in Bottlenose Dolphins Ailsa J. Hall,1 Bernie J. McConnell,1 Teri K. Rowles,2 Alex Aguilar,3 Asuncion Borrell,3 Lori Schwacke,4 Peter J.H. Reijnders,5 and Randall S. Wells4 1Sea Mammal Research Unit, Gatty Marine Laboratory, University of St. Andrews, St. Andrews, Scotland, United Kingdom; 2National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Silver Spring, Maryland, USA; 3Department of Animal Biology and GRUMM, Parc Cientific de Barcelona, University of Barcelona, Barcelona, Spain; 4Chicago Zoological Society, Mote Marine Laboratory, Sarasota, Florida, USA; 5Alterra-Marine and Coastal Zone Research, Den Burg, the Netherlands Abstract
Marine mammals are susceptible to the effects of anthropogenic contaminants. Here we examine the effect of different polychlorinated biphenyl (PCB) accumulation scenarios on potential population growth rates using, as an example, data obtained for the population of bottlenose dolphins from Sarasota Bay, Florida. To achieve this goal, we developed an individual-based model framework that simulates the accumulation of PCBs in the population and modifies first-year calf survival based on maternal blubber PCB levels. In our example the current estimated annual PCB accumulation rate for the Sarasota Bay dolphin population might be depressing the potential population growth rate. However, our predictions are limited both by model naivety and parameter uncertainty. We emphasize the need for more data collection on the relationship between maternal blubber PCB levels and calf survivorship, the annual accumulation of PCBs in the blubber of females, and the transfer of PCBs to the calf through the placenta and during lactation. Such data require continued efforts directed toward long-term studies of known individuals in wild and semiwild populations. Keywords: calf survival, endocrine disruption, risk assessment, Tursiops truncatus. Environ Health Perspect 114(suppl 1) :60-64 (2006) . doi:10.1289/ehp.8053 available via http://dx.doi.org/ [Online 21 October 2005]
This article is part of the monograph "The Ecological Relevance of Chemically Induced Endocrine Disruption in Wildlife." Address correspondence to A. Hall, Sea Mammal Research Unit, Gatty Marine Laboratory, University of St. Andrews, St. Andrews, KY16 8LB, Scotland, UK. Telephone: 44-1334-462-634. Fax: 44-1334-462-632. E-mail: ajh7@st-andrews.ac.uk The long-term data and sample collection represented in this study reflect the work of many dedicated Sarasota Dolphin Research Program staff members and volunteers. We especially thank L. Fulford, J. Greene, K. Hull, B. Irvine, S. Nowacek, M. Scott, J. Sweeney, F. Townsend, and K. Urian. While the ages of most animals considered in this article were known from observation, some ages were determined through examination of growth layer groups by A. Hohn. We are grateful to P. Reijnders, G. Donovan, and the International Whaling Commission's Pollution 2000+ Programme, who provided some of the basic support for the data referred to in this study. The NOAA Marine Mammal Health and Stranding Response Program, the National Marine Fisheries Service, and Dolphin Quest provided additional crucial sample collection and analyses. Earthwatch Institute, the Chicago Zoological Society, and Mote Marine Laboratory provided support for the long-term monitoring of the Sarasota Bay dolphins. Research was conducted under the National Marine Fisheries Service Scientific Research Permit No. 522-1569 issued to R.S. Wells. All research was conducted under Mote Marine Laboratory's Institutional Animal Care and Use Committee approval. The authors declare they have no competing financial interests. Received 31 January 2005 ; accepted 6 July 2005.
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