Pathologic Findings in Stranded Marine Mammals: A Global Perspective

Marine mammal strandings are global events that have been reported as far back as Aristotle’s time. Stranding events may involve a singular individual or a mass event that involves many individual marine mammals. Additionally, more recently, Unusual Mortality Events (UMEs) (i.e. marine mammal strandings which occur at significantly elevated rates) have been reported in various geographic regions. Many marine mammal stranding events are associated with significant pathologic findings which likely resulted in disease leading to the stranding event itself. In other strandings, particularly mass stranding events, the cause(s) of the stranding are enigmatic with little or no associated pathology which would suggest a reason for the stranding. Importantly, many of the diseases now characterized from marine mammal strandings involve emerging pathogens that have population and environmental health significance. Despite the significant advances in molecular disease diagnostics, characterization of gross and histopathologic findings remains the gold standard for characterizing the morphologic features of disease and often disease etiology using specialized tools such as immunohistochemistry. Marine mammal clinical pathology parameters are being increasingly documented from both stranded marine mammals and free-ranging marine mammal health assessments. Additionally, understanding the pathologic basis of disease and causes of mortality in stranded marine mammals is the first step in evaluating aquatic ecosystem health. In this light, recent studies have demonstrated that marine mammals are important sentinel animals that indicate environmental health concerns and parallel emerging public health issues.

The objective of this Research Topic is to provide a series of original research and review articles of the gross, histopathologic and clinicopathologic findings found in stranded marine mammals from a global research perspective. Manuscripts describing the gross, microscopic and clinicopathologic findings associated with stranded marine mammals including infectious disease and noninfectious disease and those conditions that may or may not have been associated with the actual stranding event will be accepted for review. Manuscripts are encouraged especially from geographic areas not historically well-covered in the marine mammal stranding literature. The integration of the pathologic findings from a global rather than regional perspective in a single Research Topic format will provide a novel comparative pathologic approach identifying pathologic findings common to specific geographic regions and, in turn, help to characterize emerging or re-emerging disease patterns that may be of value to marine biologists, pathologists, epidemiologists, marine mammal veterinarians and other caregivers. The Research Topic will also provide important management information for future conservation policies.

This project is posthumously dedicated to Dr. Gregory Dana Bossart. Whether you knew him as colleague, mentor, friend, family member or simply ‘knew of him’, you could not help but be awestruck by his dedication, intelligence, thoughtfulness, work ethic and passion for scientific inquiry, especially for conservation of the marine environment Many of his publications were seminal in marine mammal health, including infectious, environmental and zoonotic diseases. As we collected manuscripts for this special Frontiers edition, it was heartwarming to hear the comments from contributors. So many research scientists, field biologists and veterinarians could easily have given up and said, ‘I just can’t do this now’, especially with the added challenges posed by the current COVID-19 pandemic. Instead, contributors from around the world were determined to contribute to this collection because of their inspiration and shared commitment with Greg’s vision. The love and admiration within the marine community for Greg is phenomenal. With that said, we would be remiss if we did not say a few words about Greg as a mentor and friend. Greg had a knack for helping students realize their abilities and pursue their own independent contributions to the marine mammal community. He shared in their successes and worked tirelessly to facilitate their aspirations. Greg would involve students, early-career scientists and colleagues in projects, introduce them to collaborators and promote them and their work. Greg was a genuinely caring person. When he asked you ‘how are you doing’, he honestly wanted to know. He was always there, ready to listen and provide guidance.

If you were to ask Greg what was most important to him in life, he would say God, family and marine life (and one could argue that he had a special fondness for manatees). He believed in the beauty of nature and that God had a hand in all of it. He was in pursuit of ensuring that we all share this earth responsibly and sustainably. We miss Greg dearly, but honor and celebrate him as we carry on in our pursuits.