What Can Dolphin Exhalations Tell Us About Their Health and Reproduction?
By Bets Rasmussen, PhD, OGI School of Science & Engineering, OHSU

Volatile organic compounds in exhalant breath are a reflection of biochemical constituents circulating in the blood. Non-invasive monitoring of such compounds may give health, reproductive, physiological and seasonal information about wild dolphins.  For the last several years we have been collecting the exhaled breaths of Sarasota Bay dolphins during health assessment sessions.  From a conservation aspect, information from breath of wild dolphins may reveal (1) areas of localized, specific pollution if particular dolphins are known to frequent such regions, (2) incidence of respiratory diseases, (3) basic metabolic requirements, especially seasonal, and (4) possibly reproductive status information.  During 2004, our sample was extended from 24 to 47 from which we have analyzed exhalant breath. We continued to identify and semi-quantitate now more than 60 compounds. Several groups of compounds continued to be of particular interest: pentane (indicative of strenuous exercise); several sulfur compounds, presumably of bacterial origin; acids, again perhaps indicative of bacterial infections; and aldehydes and isocyanato compounds that may also prove to be diagnostic. With our developing interest in metabolism related to seasonal changes - either diet or endocrine-based - isoprene and 6-methyl-5-hepten-2-one levels were closely watched.  We will be continuing to monitor concentration changes that may (1) be indicative of a bacterial infection, (2) reveal seasonal changes related to fat metabolism or, (3) demonstrate chemical clues about reproductive condition. We plan a publication on at least one of these aspects in 2005.