Transcript Aquatic Life Zones

Aquatic Life Zones:
2 major categories
1. Marine (saltwater) Or
2. Freshwater
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Types of organisms
determined by:
Salinity
Temperature
Sunlight availability
D.O. (dissolved oxygen)
Nutrient availability
Major types of Organisms
1. Plankton: small free-floating
organisms
2. Phytoplankton: plant-like
• Photosynthetic
• Algae, cyanobacteria
3. Zooplankton: animal-like
• Heterotrophic
• Protozoans
• Larvae
• Copopods, cnidarians, krill…etc.
4. Ultraplankton: TINY (less than 2 micrometers)
• includes bacteria
5. Benthos (benthic organisms): bottom
dwellers – anchor to one spot, burrow, or
walk along bottom
6. Nekton: active swimmers – don’t follow
currents
7. Baleen whales: filter feeders
Plates (baleen) hang from upper
jaw – filter plankton from water
includes: 8. humpbacks and 9. blue whales
10. Toothed whales: teeth used to
bite and chew food
includes: 11. orca (killer whale) and
12. sperm whale
13. A Marine Food Chain
(example)
Marine Lifezones
13. Coastal/Neritic
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High tide to Continental shelf
(Ample sunlight) so:
high 14.NPP and D.O.
90% of all marine species
15. Coral reefs (in the coastal zone): MOST
biodiverse areas of all aquatic life zones
– “The Aquatic Rainforest”
– Hundreds of thousands of coral polyps
excrete CaCO3 skeletons
– Grow slowly, disrupted easily:
• Biggest threats: sediment run-off
• Bleaching (even from 1 degree temp
increase)
• Removal (aquariums/jewelry)
• Pollution
• Damage (tourists, anchors, natural
disasters)
• Overfishing
• Cyanide/dynamite “fishing”
–1 m2 of reef killed for every fish caught
16. Intertidal zone: shoreline between low
and high tide
• Tides caused by gravitational pull of moon
• Organisms adapted to HARSH conditions
(wet/dry, warm/cold, salty/not-so-much)
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17. Barrier Islands: islands separated from
the mainland by a shallow sound, bay, or
lagoon
• Constantly shifting beaches due to erosion
– Can be helped with a jetty
• Dunes – backbone that provides stability
– Plants hold sand in place
– Protect from natural disasters
19. Coastal wetlands: inlets, bays, sounds,
Mangrove forest swamps
20. Estuary: where freshwater meets
saltwater (mouth of a river)
22. Pelagic or Open Ocean
23. Epipelagic or photic zone:
TOP
• Sunlight layer: warmer
water, phytoplankton =
24. photosynthesis: HIGH
D.O. (dissolved -oxygen);
big fish and mammals
• Side-note: Low NPP per
unit area, but adds up!!
25. mesopelagic and
bathyalpelagic zones: MIDDLE
Dimly lit/dark – twilight/midnight
regions
–little/no producers
(little 26. D.O.),
- zooplankton, smaller fish,
squid
27. Abyssal or Abyssopelagic zone:
bottom (The Deep Dark Abyss!)
• Dark, cold, varying D.O. ,
nutrients on floor
• Organisms adapted to HIGH
pressure, COLD temps, NO light!
–Bioluminescence adaptation
• Chemosynthetic bacteria at
hydrothermal vents
28. Equation:
• 6CO2 + 6H2O + 3H2S
C6H12O6 + sulfur compounds
29. Hadel Zone…
Or Hadelpelagic zone…
- Deepest trenches in ocean
Side-notes:
• Average ocean depth 2.3 miles or
approx 12,000 ft
• Deepest hadel zone point:
30. Challenger Deep
(part of Mariana Trench) = approx
36,000 feet or 6.8 miles deep!
• Approx 16,000 psi of pressure…
compared to about 14 psi at surface