Totally true urban legends

As interpreted by the Mad Scientific crew ...

I heard that, before every spring season, the Knoxville Zoo hires rogue zoologists who kill the polar bears that they have on exhibit. When the following winter season begins, they just bring in more polar bears as replacements.

The Knoxville Zoo, in an attempt to justify this slaughter of a species already precariously balanced on a dwindling population spike, sent an internal memo to zoo administration to place emphasis on bears that are sick, but which maintain a healthy appearance.

The memo, which drew parallels between this desired polar bear population and HIV/AIDS victims, was interpreted literally, sending zoo officials into a frenzy, looking for polar bears stricken with sexually transmitted diseases.

After months of fruitless researching, they discovered a pocket of polar bears in the north Arctic that were stricken with syphillis; left unchecked, the disease has spread exponentially to the rest of the group, which numbers in the thousands. It's from this cluster of polar bears that the Knoxville Zoo culls their polar bears exhibit each year.

The location of the mass grave of polar bears has always been shrouded in mystery for years. However, amid the increasing rumors and speculation, a task force was commissioned to investigate the location of these decomposing, syphillis-ridden polar bear corpses. In 2007, they successfully tracked the bear corpses to a system of subterranean chambers located beneath Thompson-Boling Arena.

CAN YOU PROVE IT'S NOT TRUE??!