Strange Days on Planet Earth scoured the world to find its wild and bizarre stories featuring some of the planet's top researchers. From the polar wilds of the Yukon to the steamy Amazon jungles to the urban landscapes of Earth's booming metropolises and our own backyards, join investigators in the trenches and find out more about their work.

Dig deeper into the topics from "Troubled Waters" — the final episode of National Geographic's Strange Days on Planet Earth. Meet the scientific detectives working on these gripping issues and learn about how they became interested in their line of work and what their hopes and fears are for the future.

Farm Chemicals and Frogs Tyrone Hayes is on a frog hunt. Trudging through marshes and ponds, Hayes and his students have been collecting frogs, revealing bizarre anomalies inside the frogs' reproductive organs. Some of the male frogs have eggs growing inside their testes instead of sperm — they are hermaphrodites. » more

Chemical Cocktails In the northern waters of Canada's St. Lawrence River, some dead beluga whales are so full of pollutants and chemical mixtures from the water that they technically qualify as hazardous waste. It's these chemical mixtures, as opposed to any one chemical in particular, that are causing scientists like biologist Robert Michaud to worry. » more

Chemicals and Human Reproduction Shanna Swan has discovered evidence of human vulnerability to certain chemicals in the water, reporting high miscarriage rates in women who drink tap water with elevated levels of chlorine by-products. Now they are looking at the reproductive health of men in cities versus farm areas. » more

Mercury Plants Geneticist Richard Meagher can no longer eat the fish he catches from the lake near his childhood home in Georgia because mercury has seeped into its waters. By the time it travels up the food chain, mercury concentration in top predators can be over ten million time greater than in the water. But now Meagher is using plants to clean up environmental messes. » more

Crown-of-Thorns, Wetlands and Nitrogen For the third time since the 1960s, scientists have noted that the Great Barrier Reef is under siege. Repeated outbreaks of the crown-of-thorns starfish have been destroying large parts of the reef and scientists are racing to understand why. While theories for the outbreaks abound, marine biologist Katharina Fabricius and her team, including Jon Brodie and Glenn D'eath, are finding evidence that suggests that these repeated outbreaks could be related to nitrogen-rich agricultural runoff. » more

Pollutants, Tagging and the Open Ocean As invisible pollutants infiltrate our water, much of that water ends up flowing straight into our coastal zones. According to one school of thought, pollutants are diluted to safe levels by the time they reach the open ocean. But are the creatures that live here really protected from chemicals? In the past decades, researchers have become aware that some sharks, bluefin tuna, swordfish and killer whales can store large amounts of pollutants in their tissues. » more

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