Abstract
Brevetoxin exposure resulting from Karenia brevis blooms can cause morbidity with varying severity of clinical presentation (e.g., seizures, coma) and mortality events.1-3 It is one of the most frequent and reoccurring admission causes of free-ranging manatees, and immediate response and medical care are essential for survival. Blood analysis is a readily available diagnostic tool useful in the assessment of admitted manatees and in gauging the severity of underlying conditions, including toxin exposure. The objective of this study was to examine the correlation between concentrations of a suite of blood analytes and serum brevetoxin in 25 free-ranging manatees. Clinicopathological findings were similar to previous observations and indicative of systemic inflammation, dehydration, electrolyte changes, and muscle damage/myopathy from seizure activity.4 Scatter plots were constructed to measure the correlation between blood analytes and serum brevetoxin in study manatees. Strong positive correlations (≥0.6) were observed between concentrations of serum brevetoxin and sodium, chloride, white blood cell count, eosinophils, cholesterol, and partial thromboplastin time. These results indicate electrolyte imbalances, inflammation, lipid metabolism changes, and evidence for early coagulopathy associated with toxin exposure, and are consistent with previously reported gross and histopathological observations.3 Since electrolyte changes and white blood cell count are rather non-specific, clinically relevant eosinophilia, similar to other marine mammal species exposed to domoic acid, and increased partial thromboplastin time may be used as early biomarkers for brevetoxin-exposure and for the overall clinical assessment of severity of affected manatees.5 This study provides new data and information that is applicable for the initial clinical assessment and medical management of manatees admitted with evidence of brevetoxin-exposure.
Acknowledgements
The authors wish to acknowledge the hard work of the staff and volunteers involved with rescue and rehabilitation of stranded manatees and the Florida Fish and Wildlife Conservation Commission. Manatee rescue activities were conducted under USFWS permit #MA770191.
* Presenting author
+ Student presenter
Literature Cited
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4. Ball R, Walsh CJ, Flewelling L, De Wit M, Arnett E, Smith L, Gerlach T. 2014. Clinical pathology, serum brevetoxin, and clinical signs of Florida Manatees (Trichechus manatus latirostris) during the brevetoxin-related mortality event in Southwest Florida 2013. In: Proceedings of the IAAAM 45th Annual Conference. Gold Coast, Australia.
5. Gulland FMD, Hall AJ, Greig DJ, Frame ER, Colegrove KM, Booth RKN, Wasser SK, Scott-Moncrieff JCR. 2012. Evaluation of circulating eosinophil count and adrenal gland function in California sea lions naturally exposed to domoic acid. J Am Vet Med Assoc. 241(7):943–949.