The ability to collect and analyze blood samples from dolphins around the country has provided scientists a unique opportunity to better understand the mammals' physiology. In turn, researchers can begin to develop more effective ways of caring for their health and protecting them from threats in the wild.
In partnership with the Pacific Marine Mammal Center and the University of Florida's College of Veterinary Medicine, SeaWorld recently published an article in Veterinary Quarterly aimed at defining "normal" variations across various health markers of dolphins attributed to factors like sex, age, and season. Within the study, 37 different markers of health were analyzed, categorized, and compared across various groupings. As a result of these distinct groupings, for example, researchers were able to deduce whether glucose levels were higher as age increased. On a broader level, this study will help researchers better understand dolphins' health. The study will also lend insight to prevent disease and combat stressors.
Dr. Todd Robeck, vice president of conservation research at SeaWorld and study author, explained: "Similar to how your primary care doctor checks your weight, blood pressure, and overall health and compares the results against a benchmark for human health, this research provides the same benefit to the dolphin population ." He added, "We need to find ways to take better care of the animals in our oceans through research, rescue, animal care, and conservation efforts, and my research partners and I are happy to share the results of this study with other scientists and animal welfare experts around the world to help do this."
One Study, Multiple Benefits
The study focused on collecting 1,426 blood samples from 156 healthy bottlenose dolphins (59 males and 97 females) at SeaWorld parks in Orlando, Florida; San Antonio, Texas; and San Diego, California. To date, such a comprehensive and robust analysis of samples from bottlenose dolphins has not been concluded, rendering this study vastly important in the long-term health management of the species.
Researchers were then able to study and define important health benchmarks that can be applied to bottlenose dolphins in various habitats. Further, researchers were able to deduce whether environmental and biological factors made an impact on these metrics.
By setting up this large collection of "benchmark" samples, researchers have also created an important dataset that can be used comparatively in the future. This important data can be utilized by other Veterinarians and Conservation Biologists to help advance the field, improve conservation efforts, and compare new findings for the sake of observing trends.
Dr. Nicole Stacy, clinical assistant professor of aquatic, amphibian, and reptile pathology at the University of Florida's College of Veterinary Medicine, commented on the findings: "We had the opportunity to work closely with one of our former undergraduate students on this research study . . . The dataset was unique, given the number of animals in the study and their broad age range, which in turn provides many applications for the results to benefit cetacean research and conservation."
Understanding a species' physiology can be challenging to manage. Prior to this comprehensive study, most comparable studies reported solely on wild bottlenose dolphins in natural habitats. Thus, the health history, status, and outlying conditions could not be established, rendering these bottlenose dolphins as ineffective for establishing a diagnostic benchmark. By developing a robust database of reliable blood-based health information from bottlenose dolphins housed at SeaWorld, scientists now have more opportunities to apply their research. By utilizing a controlled group, such as the dolphins in SeaWorld's cares, Veterinarians can now conduct longer-term follow-up and track the dolphins' age, health, reproductive condition, and nutritional status.
SeaWorld's research on bottlenose dolphins follows a recent 2019 collaborative project with the Pacific Marine Mammal Center and the University of Florida's College of Veterinary Medicine, which created the first-ever standards for assessing the health of killer whales.
Dr. Hendrik Nollens, Pacific Marine Mammal Center's vice president of conservation medicine and science and study lead author, commented on the combined research: "It is very difficult to assess the health of a wildlife species, to in turn be able to help them, because they are typically very challenging to access and their individual histories are largely unknown." He added, "Our study not only reports on what 'normal' looks like in a large population of healthy dolphins with a known medical history, but we also compare what normal looks like across several populations of dolphins, both in human care and in the wild. SeaWorld has uniquely equipped, on-site veterinary diagnostic laboratories that generate high-quality health data that can be shared with the scientific community."
A total of 1,426 blood samples met the inclusion data for analysis. From these samples, researchers were able to generate 19,964 hematology and 32,798 biochemistry metric points using analytical tools, sampling methods, and processing techniques. Datasets included findings from bottlenose dolphins of varying age, ranging from a 4-day-old calf to a 49.8-year-old aging bottlenose dolphin. Additionally, various samples were collected throughout different seasons to account for seasonal changes in results. Finally, metrics were also analyzed according to sex.
Differentiating between sex, researchers concluded that there were 8 meaningful results between male and female bottlenose dolphins. Overall, females showcased higher median iron, Abs lymphs and MCHC. Across age categories, various differences highlighted the physical changes occuring during the aging process. Roughly 23 of the tested markers highlighted differences based on age categorizations, including an increase of glucose and globulin related to age progression. Meaningful seasonal differences were also observed, with various levels of observed markers spiking during the summer months, and declining in winter months.
These findings not only provided researchers with an important dataset to utilize in the future, but highlighted the importance of considering the influence of various factors for many health-related conditions affecting the bottlenose dolphin population. By gaining such insights related to environmental influences on the health of bottlenose dolphins, for example, conservationists will be able to pivot their efforts to maximize outcomes for wild populations.
Conserving Ocean Life
Ongoing challenges surrounding habitat loss, climate change, and a reduction in global biodiversity, continue to put marine animals at risk every day. It is imperative to conduct effective research and implement conservation efforts to protect the oceans' diverse ecosystem and marine life. Collaborating with many leading organizations, SeaWorld remains committed to these missions. Studies such as the bottlenose dolphin analysis provide long-term benefits that align with an ongoing focus on research efforts and advancements, propelled by the committed leadership of SeaWorld's Executive team. The Management Team is led by SeaWorld's interim CEO, Marc Swanson, and Founder and Managing Partner of Hill Path Capital and SeaWorld Entertainment Inc.'s Chairman of the Board of Directors, Scott Ross.