The remote operated vehicle Deep Discoverer examining the wreckage of a B-29 Superfortress bomber plane upside-down on the seafloor during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on July 9, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A bioluminescent jellyfish during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on April 24, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
The remotely operated vehicle Deep Discoverer surveying a 14-metre (46-foot) hydrothermal chimney during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on April 28, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A deep sea anglerfish living between pillow basalt rock formations, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on April 30, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A predatory tunicate, an invertebrate animal, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on April 26, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A plastic ice bag found at the Enigma Seamount, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on April 22, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
The feeding arms of a stalked crinoid animal during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan,on April 29, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A large blind lobster popping its head out of a hole during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on April 30, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
An acorn worm on the "Twin Peaks" underwater formation during an exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 30, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A parapagurid hermit crab hosting an anemone which secretes a "shell" for the crab, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on May 4, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A benthic comb jelly fish at the Ahyi Seamount, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 22, 2016.Photo: NOAA Office of Ocean Exploration and Research via AP
A cutthroat eel at 3,145 metres (1.9 miles) deep on Stegasaurus Ridge, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 27, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A crab, bottom, stands near an unidentified purple orb during a deep sea expedition around the Channel Islands off the coast of California, in July 2016. Photo: Nautilus Live/Ocean Exploration Trust via AP
A vampire squid (Vampyroteuthis infernalis), a deep-sea cephalopod, during an overnight dive in the Gulf of Mexico. Photo: ECOGIG/Nautilus Live/Ocean Exploration Trust via AP
A can on an unnamed seamount at a depth of 3,306 metres (2 miles), during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 29, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A cusk eel with an unusual bulbous head shape with small eyes, large nostrils, and a mouth placed low on the head, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 29, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP
A squid as the remote operated vehicle Deep Discoverer descends to the seafloor of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 30, 2016. NOAA Office of Ocean Exploration and Research via AP
A fish, of the family Aphyonidae, which had never before been seen alive, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan, on June 30, 2016. Photo: NOAA Office of Ocean Exploration and Research via AP