WDCS, along with former SeaWorld orca trainers, John Jett and Jeff Ventre, will reveal newly-discovered evidence documenting the death of two orcas at SeaWorld facilities by mosquito-transmitted viral diseases, including the West Nile and St. Louis encephalitis viruses, at the 4th Florida Marine Mammal Health Conference to be held in Sarasota, Florida at the Mote Marine Laboratory, April 24-27th.
WDCS hopes that the poster presentation will focus attention on the unspoken and unseen risks to orcas in captivity due to the unnatural amount of time that they spend at the surface of the water in the shallow pools that they are forced to live in.
“We continue to be astonished at the serious information that is being discovered about the condition of orcas in captivity, and that hasn’t yet been shared with the public,” said Courtney Vail, campaigns manager for WDCS. “I think it is safe to say that no one would have thought of the risks that mosquitoes might pose to orcas in captivity, but considering the amount of time they unnaturally spend at the surface in shallow pools at these facilities, it is yet another deadly and unfortunate consequence of the inadequate conditions inherent to captivity.”
WDCS and others reported on these newly-discovered studies documenting the cause of death of both 25-year old orca Kanduke, who died in 1990 at SeaWorld Orlando due to St. Louis encephalitis virus, and Taku, a 14-year-old male orca held at SeaWorld San Antonio, who died after being fatally infected with the West Nile Virus in 2007. Both viruses are transmitted via mosquito bite from an infected mosquito that carries the avian-borne virus.
“Logging (floating at the surface) was commonly witnessed while I was at SeaWorld, especially at night, which provided a static landing platform for mosquitoes,” said Dr. John Jett. “Free ranging orcas, conversely, are on the move and not exposed to mosquitoes. They dont remain still long enough and mosquitoes are weak fliers, limited to coastal areas. This poster is an important introduction to a topic sure to raise eyebrows."
Captive orcas spend an inordinate amount of time logging compared to their wild counterparts. Logging behavior combined with living in low-latitude environments in clear, shallow and reflective pools, results in sun overexposure and possible immunosuppression, which may make them susceptible to diseases carried by biting insects. This important information reveals that the premature death of orcas in captivity is sometimes caused by stressors unique to captive environments.
"Flaviviruses, like those that killed Kanduke and Taku, are transmitted through the bite of a mosquito and are not typically lethal in mammals,” said Dr. Jeff Ventre. “These two similar deaths are significant as they demonstrate a direct causal link between captivity and early mortality in captive orcas. They also illustrate that Duke and Taku may have had compromised immune systems. Captive orcas often suffer from poor oral health, general deconditioning, and chronic antibiotic usage.”
Further analysis is required to determine the presence of, and exposure to, these avian and mosquito-borne viruses in captive cetacean populations. The West Nile Virus has been isolated in some populations of wild dolphins who may be similarly susceptible as a result of sustained surface behaviors in shallower coastal waters.
As the compelling evidence regarding the formerly unseen and devastating realities behind orcas in captivity continues to mount, WDCS encourages the public to make the right choice by not attending a marine park or aquarium that keeps whales and dolphins in captivity. WDCS is committed to exposing the reality of captivity and seeks an end to the confinement of whales and dolphins at marine parks around the world.