Ep 7. Zombie Sharks

In Shark Week season 2014 episode 7, entitled "Zombie Sharks," viewers are taken on an eerie exploration of the effects of a parasite known as the gnathiidae on blacktip sharks in the waters off of the coast of Florida. Experts have discovered that this parasite, commonly found on coral reefs, is capable of causing a sort of zombification in these sharks, leading to erratic behavior that makes them more vulnerable to predation.

To better understand this phenomenon, host and oceanographer Greg Skomal travels to Florida to meet with Dr. Michael Heithaus, a marine biologist who has been studying blacktip sharks in the area for over a decade. Heithaus explains that gnathiidae is a small crustacean that attaches itself to the skin of the shark and feeds on its blood. While this, in itself, is not necessarily harmful to the shark, the bites can cause intense irritation that can lead to erratic and exaggerated movements.

In an attempt to get a more in-depth look at this phenomenon, Skomal teams up with a group of scientists who are developing a new underwater camera technology that will allow them to take high-resolution footage of the sharks in their natural environment. With this technology in hand, Skomal and his colleagues dive into the waters off of the Florida coast, searching for blacktip sharks that have been affected by gnathiidae.

As they explore, Skomal and his team encounter a number of sharks that seem to be displaying unusual behaviors, including unusual swimming patterns and sluggish movements. While it's difficult to draw firm conclusions from this limited observation, it's clear that something is causing these sharks to act differently than their unaffected counterparts.

To gain a better understanding of what's happening on a physiological level, Skomal and Heithaus take a closer look at a few of the infected sharks. Using a portable lab setup on their boat, they extract blood samples from the sharks and analyze them for any potential clues about the parasite's effects. What they find is surprising: the infected sharks have significantly higher levels of stress hormones in their blood than the uninfected sharks, suggesting that the gnathiidae is causing a serious strain on their systems.

In addition to studying the infected sharks, Skomal and his team also attempt to get a better understanding of the gnathiidae itself. By collecting samples of the parasite from the coral reef, they hope to create a better understanding of its life cycle and how it interacts with other species in the ecosystem.

Throughout the episode, Zombie Sharks takes viewers on an eerie journey into the world of parasitic infestations, offering a glimpse into how even the most top predators can be brought to their knees by an unseen invader. With stunning cinematography and expert analysis, this episode is an excellent addition to the Shark Week library, offering a sobering reminder of just how much we have yet to learn about the mysterious world beneath the waves.