For more than a decade, researcher Zeb Hogan has spent much of his time traveling around the world on a singular mission: to find and learn more about the world’s largest freshwater fish. Through his photographs and a show he hosts on Nat Geo Wild called “Monster Fish,” he’s helped many people discover and appreciate these beasts… The highlights of his research on the conservation status and accurate size of various fish are being presented beginning March 25 at the National Geographic Museum in Washington, D.C., an exhibition Hogan describes as a “one-stop-shop for everything megafish.”… Olaf Jensen, fish ecologist at Rutgers University, says that the exhibit is “great stuff, Zeb has done a fantastic job of bringing the conservation challenges regarding big fish to a public audience.” Jensen has collaborated with Hogan to study the world’s largest trout, known as a the taimen, in Mongolia. They have found that these species require large stretches of river to survive, and that there is a growing number of people catching and releasing the animal… These fishermen must buy permits from the government, money which goes to conservation efforts. While overfishing can harm animals, and has in the past in many areas, well-regulated catch-and-release fishing can be beneficial, since it can help prevent development and damming of river areas, Jensen adds.