Ep 1. Atomic Assassin

In season 5 episode 1 of River Monsters, titled "Atomic Assassin," host Jeremy Wade investigates reports of mysterious and deadly fish in the lakes and ponds around Chernobyl, Ukraine. Wade knows that these bodies of water have been contaminated by radiation from the nuclear disaster in 1986, but he is determined to learn more about the creatures that have adapted and thrived in this harsh environment.

Wade's first stop is a small lake that is home to some of the largest fish in the area. He meets with local fishermen who claim to have seen massive catfish that are bigger than anything they've ever caught before. Wade is skeptical at first but decides to try his luck and catches an enormous fish that he suspects could be the legendary Chernobyl catfish.

Wade then heads to a nearby river that has been affected by the fallout from the nuclear disaster. Here, he meets with a group of scientists who are studying the fish in the area to learn more about how they have adapted to the radiation. Wade takes a sample of the river water and tests it for radiation levels before setting out on the river with the scientists to catch some fish.

As they fish, Wade and the scientists discuss the dangers of eating fish from the contaminated waters and the potential long-term effects of the radiation exposure. They catch several different species including pike and perch, which have been known to carry high levels of radiation in their tissues. Wade takes a sample of each fish for testing before releasing them back into the river.

Finally, Wade heads to a massive cooling pond near the Chernobyl power plant. This body of water is highly radioactive and known to be home to some of the largest and most dangerous fish in the area. Wade and his team use a combination of traps and baited hooks to catch a variety of species including carp and wels catfish. Each fish is tested for radiation before being released back into the pond.

Throughout the episode, Wade speaks to experts about the long-term effects of the radiation on the fish and the potential risks to human health from eating contaminated fish. He also explores the adaptations that the fish have undergone in response to the radiation and the unique ecosystem that has emerged in this contaminated landscape.

Overall, "Atomic Assassin" offers a fascinating look at the impact of the Chernobyl disaster on the natural world and the resilience of the creatures that have survived in its aftermath. Jeremy Wade's determination to uncover the truth about these mysterious fish makes for a gripping and informative episode that will leave viewers with a greater appreciation for this complex and fragile ecosystem.