Download Mesopelagic Zone

Mesopelagic Zone
Or....
•  Below the epipelagic zone and above the
bathypelagic zone.
•  Depth: Extends from surface 200 meters
(656 feet) to 1,000 meters (3,286 feet.)
Temperature
•  Temperature: 5-4
degrees Celsius,
41-39 degrees
Fahrenheit
Light
•  Light: called "the
twilight zone" due to
the scarce amounts of
light.
Facts Continued
•  Oxygen: Is in between the oxygen-rich zone, and the
less oxygen deep waters.
•  Pressure: up to 1470 pounds per square inch and
increases with depth.(10,100,000 Pa)
•  Organisms survive by spending their days in this zone
(sunlight), then rise to the surface at night.
Currents
•  Currents – Water residence time in the
mesopelagic zone is approximately 100 years or
roughly one ninth that of the bathypelagic zone.
•  Water Movement is known to be hydrologically
slow moving in this zone.
Abiotic Factors
Abiotic Factors:
Sun (light) water (salt) rocks sand
oxygen predation system
clouds
Biotic Factors
Vertebrates
•  Vertebrates: gills are
more efficient,
minimize movement,
swordfish, squid,
wolffish, and some
species of cuttlefish,
many are
bioluminescent. Many
will rise to the
epipelagic zone at night
to feed.
Invertebrates
In the Mesopelagic zone, we
see invertebrates like krill,
arrow worms, shrimp, and
copepods.
Animal Facts
•  Predator avoidance Strategies --Countershading, transparency -Reduction of silhouette: bioluminescense.
•  With surface light in the background, animals can create a
detectable shadow; ventral photophores help animals blend with
the background
•  Some fish are also found in the bathypelagic zone.
•  Angel shark, brittle star, ceolocanth, clams, crabs, cuttlefish, eels,
gray whales, greenland shark
Primary
Producers
Zooplankton: krill, copepods,
ostracods, arrow worms, and
some types of squid. Mollusks: Squids and
cuttlefish.