Project Title: Investigation of brevetoxin induced morbidity and mortality in stranded sea turtles from central west Florida
Project Manager: Dr. Deborah Fauquier
Organization: Mote Marine Laboratory (Non-Profit Organization)
Grant Amount: $22,360.00
Completion Date: 2006-06-27
Summary: This is a collaborative project between Mote Marine Laboratory, Fish and Wildlife Research Institute, and the University of Illinois to investigate the extent that brevetoxin intoxication may cause morbidity and mortality in stranded sea turtles along the central west coast of Florida. Brevetoxin levels in tissues and body fluids from stranded sea turtles during red tide events and in the absence of red tide will be determined. Control tissues from presumptively unexposed dead stranded animals from the east coast of Florida will be obtained. The spectrum of gross and histologic lesions that may be associated with the presence of brevetoxin in tissues from stranded sea turtles will be investigated. Lastly, we will investigate any correlations between brevetoxin levels in dead animals and Karenia brevis cell counts along with the covariates of season, stranding location, gender, reproductive condition, and body condition.
Results: Brevetxicosis appeared to be the primary cause of stranding in 34 of 40 (85%) live or dead stranded sea turtles during 2005 off the west coast of Florida during a severe red tide event. Although additional animals were not tested, it can be assumed that a similar proportion of turtles stranded during this time were also affected by brevetoxin intoxication. Sea turtles stranded dead during the periods of high red tide cell counts, while live turtle stranded during periods with lower cell counts indicating that there is a threshold at which red tide exposure becomes fatal. Findings from this study are only preliminary, but the fact that the majority of the live and dead animals sampled during the 2005 red tide event were positive for brevetoxin indicates that brevetoxin intoxication may play a larger role in the morbidity and mortality of sea turtles off the west coast of Florida than previously recognized. (Author: Dr. Deborah Fauquier)