A team of Japanese researchers found an unusual community of bacteria thriving in the canyon called Challenger Deep. At 36,000 feet below sea level, it is the lowest point on Earth's surface and the deepest part of the Mariana Trench. The microscopic bacteria found there are called heterotrophs, and cannot produce their own food, and thus, must eat what they find in the water. The researchers think the bacteria probably survive on sinking particles, such as dissolved fecal pellets or dust. They may also be deriving food from geologic processes such as earthquake-triggered landslides, which send organic-rich sediments into the canyon's depths. Using a remotely operated vehicle, the research team also found that microbes were most abundant near the surface and on the ocean floor, where they can find the most food.
Read more in Scientific American.