Health assessment research in Sarasota Bay
By Randall S. Wells, PhD

The 2006 Sarasota Bay Health Assessment team.

Starting in 1987, the SDRP pioneered a program of health assessment of free-ranging bottlenose dolphins in an effort to be proactive in understanding health threats to dolphins, providing an alternative to the previous approach of recovery and examination of beach-cast carcasses. This approach continues to evolve, and subsequent programs in Texas, along the mid-Atlantic coast, and in the Indian and Banana River system of Florida have built upon the model we developed. Our capture-release health assessment program during June 2006 in Sarasota Bay, supported primarily by Dolphin Quest, involved more than 25 different concurrent projects (many of them summarized in this issue). The work was conducted by 110 staff members, collaborating scientists, graduate students, dolphin handlers, and veterinarians from around the world, including Argentina, Australia, Canada, China, Denmark, England, Germany, Guatemala, Scotland, and Tasmania. Colleagues from Argentina and China participated in order to learn how we safely capture and handle dolphins, for application to their own conservation programs with Franciscana dolphins and the most endangered cetacean, the baiji, in the Yangtze River. Continuing education opportunities were provided to staff from nine different zoos and aquaria, with the expectation that their experiences with Sarasota's dolphins would help them to better educate the public about bottlenose dolphins through their institutions’ education programs.

Over the course of five days in the field (a foreshortened session due to Tropical Storm Alberto), we handled 20 dolphins, four of these for the first time. We completed sampling for our 10-year project to attempt to understand the seasonal variations in distribution and effects of environmental contaminants in dolphins (related to seasonal blubber dynamics). Of particular interest this year was the possibility of effects on health or body condition from the prolonged and severe red tide of 2005. None of the long-term resident dolphins were known to have died from red tide toxicosis (brevetoxicosis) during 2005. No specific indications of health impacts were noted during the session, but the below-average body condition of some of the sampled dolphins was consistent with declines in available resources resulting from the red tide. The three 2-year-old calves measured in 2006 were significantly smaller than same-age calves measured in previous years, and their mothers and the adult males measured during this session weighed less than expected.