Sunlit Zone
Base of Marine Food web in this zone
Phytoplankton
This ocean zone lies just below the Sunlight Zone and is known for its dim, blue light.
Twighlight Zone
This ocean layer begins at roughly 1,000 meters and receives no sunlight.
Midnight Zone
What is the abyssal plain?
This flat, extensive seafloor region in the Abyss covers large portions of the ocean basins and is often blanketed in fine sediments.
What are oceanic trenches?
These are the deepest, narrow, and long depressions on the ocean floor, often reaching depths over 10,000 meters.
What procsess does Plankton make Oxygen
The Twilight Zone extends from about 200 meters down to ___ meters
1,000 meters
What is bioluminescence
Many creatures in the Midnight Zone have evolved to produce their own light for hunting, communication, or defense.
What is deep-sea gigantism?
Some deep-sea animals grow significantly larger than their shallow-water relatives — a phenomenon scientists call this.
What is the hadal zone?
This zone, found within trenches, is characterized by extreme pressure, near-freezing temperatures, and complete darkness.
Marine mammel that uses echolocation
Dolphin
Many creatures in the Twilight Zone produce this natural light to communicate or attract prey.
bioluminescence
What are adaptations for high pressure and cold environments?
Due to the extreme pressure and cold, animals here often have adaptations like large eyes (if they can still see any light) or specialized body structures.
What is a whale fall?
These long-lasting scavenger communities form when a whale carcass sinks to the seafloor, providing concentrated food and habitat.
What are deep-sea snailfish?
These gelatinous fish species, including bulb-headed snailfish, are specially adapted to survive at the bottom of trenches like the Mariana Trench.
Sunlit Zone extends to about this maximum depth in meters
200 meters
Due to low light, animals in the Twilight Zone often have this adaptation to help them see better.
large eyes
What is an anglerfish
This large, deep-sea fish is known for its fearsome appearance and the bioluminescent lure it uses to attract prey in the Midnight Zone.
What are barophiles?
Organisms adapted to survive under extreme pressure are often given this name (also called piezophiles).
These unique biological communities in trenches include beds of clams, mats of bacteria, and fields of tube worms, often relying on chemicals instead of sunlight.
chemosynthetic communities
layer of rapid temperature change found near the base of the Sunlit Zone is called
thermocline
This term describes the zone’s extreme pressure and cold temperatures, requiring special adaptations for survival.
high pressure and cold environment adaptations
What is marine snow
Although sunlight doesn't penetrate, some energy reaches the Midnight Zone in the form of organic matter sinking from the zones above.
What is chemosynthesis?
This process, used by bacteria at hydrothermal vents and cold seeps, makes organic matter without sunlight by oxidizing chemicals like hydrogen sulfide.
Organisms in trenches have special proteins and biomolecules that help them resist this intense environmental factor caused by the weight of water above.
hydrostatic pressure