"I started a project to find and study the world's largest fresh water fish. Fish that can grow over six feet long or weigh more than 200 pounds. There are about 30 different fish that can get that big." University of Nevada Research Biologist, Zeb Hogan, Ph.D.  is on a global mission to catch - and release - them. "All over the world in Asia, Australia, South America, Africa and obviously here in North America."

Zeb's number one goal is to prevent these fresh water giants from disappearing. "A lot of them are on the verge of extinction. I really hope we can find better ways to protect these fish before they disappear." His fascination with monster fish started as an undergrad. He worked on the Colorado River and in the Grand Canyon which eventually led him to the Mekong River in Southeast Asia where he vividly remembers natives catching a 600 pound giant catfish! "When I saw that big fish - the catfish caught in Thailand - it was one of the last of these big fish fisherman had caught over there."

Zeb started a conservation project to not only save them but to also raise awareness they exist. His quest caught the attention of National Geographic. "The show is called Monster Fish and airs on Nat Geo Wild." He just wrapped up shooting the sixth season. Camera crews follow as he chases down aquatic behemoths and explains their role in our ecosystems. "First it will be the big fish that disappear, but then humans will start feeling the impacts as well of pollution; of an unhealthy river."

Zeb's efforts have changed fishing practices around the world and the Mekong Giant Catfish is now listed as critically endangered. Even in the murky waters, it's clear his underwater work is making a difference. However, Zeb says he is not reeling it in yet. "People ask me a lot if there are still big fish out there that we haven't discovered yet and I think there are."

Zeb’s work with Monster Fish is on display at the National Geographic Museum in Washington, D.C. right now. However, the 6,000 square foot exhibit is heading to Northern Nevada! 'Monster Fish: In Search of the Last River Giants' will be at The Discovery Museum in Downtown Reno from November 14, 2015 – April 26, 2016.

The next showing of Monster Fish on Nat Geo Wild is Friday, September 4th at 5 p.m.