Every year hundreds of marine mammals are transported by air. This is done for a variety of purposes. While removal from their home environments and transporting is stressful for the animals, travel by air is least harmful.
Globally, airfreight companies and many major airlines offer transit services for a wide variety of animals. Elephants, cattle, horses, and whales are some of their larger “passengers.” In almost every case, flying is preferred to other forms of transport.
In the United States, the governing law is the Marine Mammal Protection Act (MMPA) of 1972 (as amended over the years). Through a permitting process, the MMPA carefully regulates the import and export of marine mammals. The basic intent is to ensure healthy populations of species as well as education of the public.