SCIENCE

The National Oceanic and Atmospheric Administration (NOAA) is undertaking an investigation of one of the most mysterious places on Earth: the Mariana Trench. (Christian Science Monitor)

Use our lesson plan to learn more about “Protecting the Mariana Trench.”

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

You can see the round lure of this deep-sea anglerfish between its eyes. The anglerfish is an ambush predator that waits for prey to be attracted by the lure before rapidly capturing it in one gulp with its large mouth. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

Liquid carbon dioxide bubbles up from fractures adjacent to white-smoker chimneys around NW Eifuku, a submarine volcano. Image courtesy of the NOAA Vents Program

This beautiful creature is a stalked crinoid, also known as a sea lily. Crinoids are echinoderms, the same family as sea stars. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

Mounts of pillow lava form when basaltic lava erupts underwater. Cold seawater chills the erupting lava, creating a rounded tube of basalt crust. As the newly erupting lava pushes through the chilled basalt crust, it can form scratches on the pillow surface, called striations. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

This isn’t a plastic bag, it’s a predatory tunicate. These animals anchor themselves along trench walls and the seafloor, waiting for tiny animals to drift or swim into their hood-shaped mouth. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

This unusual bamboo coral (Lepidisis) lives in deep, dark ocean waters. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

The rich deep-sea ecosystem is represented by this pretty “crinoid Christmas tree,” in which a deceased coral is colonized by crinoids, a large basket star, and an anemone.  Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

A sixgill shark coasts over a dazzling garden of coral. Look closely, and you can see brittle stars hiding in in the corals. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

Discussion Ideas
Read through our terrific activity “Protecting the Mariana Trench.” Adapt its questions to NOAA’s current expedition to the deepest place on Earth—that’s what we did here.

• What important resources might exist in and around the Mariana Trench? Read through this article from NOAA for some help.
  • Metals (such as cobalt, nickel, manganese, and iron) are rich in the area, the so-called Prime Fe-Mn Crust Zone (PCZ). These metals are important for industrial use, especially as steel alloys.
  • Another untapped economic resource thought to be abundant in the Mariana Trench is methane hydrates. Methane hydrates are dense deposits of methane locked inside of ice crystals found on the ocean floor. Methane hydrates may be used as sources of natural gas. The USGS estimates that the total amount of carbon locked away inside of methane hydrates could be twice as much as the amount that exists in all the world’s known fossil fuels. (Learn more about methane hydrate deposits here.)
  • Another possible resource is the remote location of the trench itself. The Challenger Deep, the deepest part of the Mariana Trench, sits on a subduction zone, where the Pacific plate is crashing beneath the Philippine plate. Some scientists argue that this makes the Challenger Deep the perfect place to dispose of toxic nuclear waste. The material would be far from human habitation and would melt into the Earth’s molten mantle. An international agreement (the London Convention) currently makes this proposed method of nuclear waste disposal illegal.

• Why does NOAA think it is important to preserve the Mariana Trench and its resources?
  • The Mariana Trench is an ecosystem that has been impacted very little by human activity and provides a pristine research area for scientists.
  • In addition, exploration of the Mariana Trench could benefit humanity. “[T]he same adaptations that allow organisms to live in the Trench’s extreme conditions could also lead to breakthroughs in medicine and biotechnology. Rocks from the trench could lead to a better understanding of Earth’s plate tectonics, and the area’s frequent earthquakes and tsunamis. Additionally, scientists believe the trench’s mud volcanoes may have provided the perfect conditions for Earth’s first life to thrive.”

• What is unique about the physical geography of the Mariana Trench? Read through this NOAA article for some help.
  • It contains the deepest known point in the ocean, the Challenger Deep.
  • The trench is home to the largest active mud volcanoes in the world, as well as regular lava volcanoes (which are still pretty awesome).
  • Fractures in the seabed leak nearly pure liquid carbon dioxide.
  • The trench marks one of the most active subduction zones in the world. (Subduction! Our favorite geologic activity.)
  • The entire trench is dotted with ocean vents, those weird and wonderful geologic features that jet superhot, toxic fluids into the freezing sea.

• What is unique about the organisms that live in and around the Mariana Trench?
  • Some of the corals surrounding the Northern Mariana Islands thrive around island communities built on basalt rock. (This is unusual.)
  • It is one of the few areas where photosynthetic communities (in which organisms convert light energy to chemical energy) coexist with chemosynthetic communities (in which organisms convert some chemical compounds into organic nutrients).
  • Ocean trenches can be rich in biodiversity. For example:
    • At a trench’s deepest points, most animals, many related to sea stars or jellies, are made mostly of water and gelatinous material that cannot be crushed as easily as lungs or bones. Many of these creatures navigate the depths well enough to even make a vertical migration of more than 1,000 meters (3,281 feet) from the bottom of the trench—every day. Even the fish in deep trenches are gelatinous. The bodies of several species that dwell at the bottom of the Mariana Trench have been compared to tissue paper.
    • Many fish species have adapted to life in dark ocean trenches through use of bioluminescence, meaning they produce their own “living light” in order to attract prey, find a mate, or repel a predator.

• What do scientists hope to discover on their expedition?
  • “In the coming months, we expect to explore bottomfish habitats, new hydrothermal vent sponge communities, and seamounts, as well as subduction zone and trench areas.”
  • Already, “a team of researchers … dropped a microphone down to the bottom of the Challenger Deep, only to discover that the area is actually extremely noisy, with sounds reverberating from whales, ships, and typhoons miles above the trench.”

TEACHERS’ TOOLKIT

Christian Science Monitor: NOAA looks for answers in the mysterious Mariana Trench

Nat Geo: Protecting the Mariana Trench activity

Nat Geo: What is an ocean trench?

NOAA Okeanos Explorer: 2016 Deepwater Exploration of the Marianas