Deep Sea Habitat Background:
The deep sea includes the deepest, darkest, coldest parts of the ocean. Eighty percent of the ocean consists of waters in the deep sea, which are water depths greater than 1,000 meters (3,281 feet). Parts of the deep sea described here are also included in the pelagic zone, but these areas in the deepest reaches of the ocean have their own special characteristics. Most areas are cold, dark, and inhospitable to us humans, but support a surprising number of species that thrive in this environment.
How Deep Does the Ocean Get?:
While the parts of the ocean referred to as "deep sea" are over 1,000 meters, the deepest part of the ocean lies almost 11,000 meters (over 36,000 feet) below the ocean surface. This spot is called the Challenger Deep after a British Ship, the Challenger II, that first surveyed it using sound. The Challenger Deep lies within the Mariana Trench, which is located in the Pacific Ocean.
Challenges Faced by Marine Life in the Deep Sea:
- Lack of light: The only available light in the deepest regions of the ocean comes from bioluminescence, which is a chemical reaction in a creature that produces light. In this realm you’ll find fish with large eyes, adapted to taking in any light that appears, and some without eyes, because they have adapted to live without them. Since the available light makes it difficult to find mates, some creatures rely on sense of smell to find others in their species. As new techniques to explore the ocean floor are developed, scientists are discovering more species all the time.
- Water pressure: Because water pressure is so great, creatures have adapted so their bodies don’t collapse under the stress. These adaptations include having soft bodies without any excess spaces that would be subject to water pressure.
- Temperature: With the exception of hydrothermal vent communities, where high temperatures are present, the deep sea is a cold place, with temperatures close to freezing (about 2-4 degrees Celsius, or about 35-39 degrees F).
Marine Life Found in the Deep Sea:
As humans adapt to studying the deep oceans by developing more sophisticated submersible vehicles and other equipment, more deep sea species are being discovered.
Marine life found in the deep sea includes the anglerfish, which attracts its prey using a bioluminescent lure, and then quickly snatches it into its huge teeth. It also includes the deepest-living fish, Pseudoliparis amblystomopsis, which lives over 4 miles below the ocean surface and was first filmed in October 2008.
In March 2012, James Cameron became the first human to take a solo trip to the Challenger Deep - the deepest part of the ocean. He reported seeing "shrimp-like amphipods," and scientific analysis of samples taken at the site is ongoing. There was one previous visit to the site by humans in 1960, in which Jacques Piccard and Don Walsh reported seeing flatfish.