Transcript The Ocean Zones Power Point

The Ocean Depths
Zones of the Ocean
• Epipelagic- Photic
Zone (500- 650 ft)
– Sun, plants,
photosynthesis, O2
• Mesopelagic- Dim
light, but no plants
– No photosynthesis
– 660-3000ft
• Deep seaperpetually dark
• Overturn- oxygen rich water reaches
the bottom in the Atlantic (S. of
Greenland) and just north of Antarctica
• Great Ocean Conveyer- regulates the
Earth’s climate and replenishes
oxygen to the deep sea.
The Twilight World- (the
Mesopelagic) 3,000 ft- dim light
• Main thermocline- large
temperature change
• Animals: Midwater
***have photophores = bioluminescence
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Zooplankton
Copepods***
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Siphonophores Krill ***
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Shrimps***
Comb Jellies
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Ostracods
Larvaceans
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Amphipods
Pteropods
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Chaetognaths
Squids
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Jellyfish
Vampire squid
Mesopelagic Fish:
1. Bristlemouth
Most abundant fish on earth
2. Viperfish
3. Dragonfish
4. Hachetfish
Mesopelagic Adaptations
• Only about 20 % of food produced in the
epipelagic makes it to the mesopelagic.
1. Small size: Hides easily and uses less energy
2. Large mouths- hinged extendable jaws (large
teeth)
– Usually will eat anything that will fit in mouth
3. Non-migrators
(couch-potato fish)
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Copepods and krill filter detritus and
fecal pellets of epipelagic copepods.
Fishes, shrimps, and squids:
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Ambush Predators
Flabby, watery, flesh instead of muscle
no swim bladder
soft, weak bones
no spines or scales
Blob Fish
Vertical Migrators
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Swim up at night to feed.
Well developed muscles and bones
Swim bladder for buoyancy
Tolerate temperature changes
Vertical Migration is important in transporting food into deep
water
• This increases food supply in mesopelagic
• Non-migrators feed on migrators
4. Sense Organs
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tubular eyes- up or forward to increase
field of vision
yellow filters can distinguish natural light
from bioluminescence
lateral lines
very large eyes = more surface area to
collect light
5. Coloration and body shape
• Countershading- black backs and silvery
sides
• Reduction of the silhouette
• Laterally compressed bodies reduce
outline
Bioluminescence
6. Bioluminescence
• Counterillumination- light production that
helps animal blend in with background
light filtering down from the surface
• Most common color is blue and the 2nd
most common color is green
• Light can be from photophores, special
cells, glands, ink.
• Can be used in communication and to
attract mates, vision, or to lure prey.
Oxygen Minimum Layer
• Gas exchange
from atmosphere
& photosynthesis
• 1,600 ft- O2
minimum layer
The World of Perpetual Darkness
• Bathypelagic- 3,00013,000 ft
• Abyssopelagic-13,00020,000 ft
• Hadalpelagic- 20,000 –
36,000 ft
• Fish have little color
• bioluminescence is
used for attracting
prey, communication,
& courtship
• many are blind or
have small eyes.
Life in the Darkness
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5% of food makes it to deep water
“Couch potato” fish
Huge mouths and expandable stomachs
Anglerfish use “lure” to catch prey
Anglerfish
Sex in the Deep
• Hermaphrodites- both sex organs
• Bioluminescence – attracts mates
• Pheromones- special chemical released
to attract mates
• Male parasitism- anglerfish attaches to
female for life
Living Under Pressure
• Lack of swim bladder is due to high energy
cost of filling it under extreme pressure.
• Divides zones: deepest living fish is
27,000 ft.
• Pressure effects enzymes that control
metabolism
Life in the Benthos
• Benthic animals have more time to find food and eat
it.
• Slow decomposition of detritus
• Fecal pellets are an important source of organic
matter.
• Slow growth but long life (Deep-sea gigantism)
Hydrothermal Vents
• Undersea hot springs associated with midocean ridges
• Discovered in 1977 by Bob Ballard
• Tube worms (3.3 ft long)
• Clams (12 in)
• Mussels
• Shrimps
• Crabs
• Fishes
Chemosynthesis
• Seawater trickles down
through the cracks in the
crust, is heated and emerges
at hydrothermal vents.
• Contains hydrogen sulfide
(H2S) and other minerals
• Bacteria use H2S to make
organic matter which is
chemosynthesis
• When they crystallize they
form black smokers and
chimneys.
• Primary producer is
chemosynthetic bacteria
Tube Worm
• The giant tube worm
contains symbiotic
bacteria
• Worms supply raw
materials
• H2S is toxic to most
animals but tube
worm has special
hemoglobin