The document discusses the different divisions of the marine environment including pelagic, benthic, and land environments. It notes there are over 250,000 known marine species ranging from bacteria to the largest animal, the blue whale. The pelagic environment contains more biomass than the benthic environment due to greater sunlight. Organisms are classified into taxa using the Linnaeus system of five kingdoms. Marine life also exhibits adaptations to conditions like temperature, salinity, dissolved gases, and water transparency.

1. Chapter 12:
Marine Life and the
Marine Environment
by Lily Young

2. Main Divisions of the
Marine Environment
• Over 250,000 known marine species
(and increasing)
• Range from microscopic bacteria and
algae to the world’s largest animal,
the blue whale
• Pelagic = “of the sea”
• Benthic = “sea bottom”

3. Main Divisions of the
Marine Environment
Number of species:

4. Main Divisions of the
Marine Environment
Number of species: 1. Land

5. Main Divisions of the
Marine Environment
Number of species: 1. Land
2. Benthic

6. Main Divisions of the
Marine Environment
Number of species: 1. Land
2. Benthic
3. Pelagic

7. Main Divisions of the
Marine Environment
Number of species: 1. Land
2. Benthic
3. Pelagic
Which has more biomass: the pelagic
or benthic environment?

8. Main Divisions of the
Marine Environment
Number of species: 1. Land
2. Benthic
3. Pelagic
Which has more biomass: the pelagic
or benthic environment?
The pelagic environment (more
sunlight)

9. Classification of Marine
Organisms
Carolus Linnaeus devised classification
system in 1758

10. Classification of Marine
Organisms
Carolus Linnaeus devised classification
system in 1758
5 kingdoms:

11. Classification of Marine
Organisms
Carolus Linnaeus devised classification
system in 1758
5 kingdoms:
1. Anamalia: multi-celled animals
2. Fungi: mold and lichen
3. Plantae: multi-celled plants
4. Monera: single-celled, lack nucleus
5. Protoctista: single and multi-celled,
with nucleus

12. 5 Kingdoms

13. 5 Kingdoms
What is the term for placing organisms into
various categories?

14. 5 Kingdoms
What is the term for placing organisms into
various categories?
taxonomy

15. Classification of Marine
Organisms
3 domains, based on habitat and mobility:
1. Plankton = floaters (algae, animals,
bacteria within ocean currents)
2. Nekton = swimmers (fish, squid,
marine mammals and reptiles)
3. Benthos = bottom-dwellers (crab,
starfish, etc.)

17. What is the term used to describe squid, who spend
part of their life as plankton?

18. What is the term used to describe squid, who spend
part of their life as plankton?
meroplankton (mero = “a part”)

19. What is the term used to describe squid, who spend
part of their life as plankton?
meroplankton (mero = “a part”)
What is the term for the opposite of meroplankton?

20. What is the term used to describe squid, who spend
part of their life as plankton?
meroplankton (mero = “a part”)
What is the term for the opposite of meroplankton?
holoplankton (“holo” = whole)

21. Adaptations to Physical
Conditions of the Ocean

22. Adaptations to Physical
Conditions of the Ocean
Cold water

23. Adaptations to Physical
Conditions of the Ocean
Cold water
• hard to swim through (high viscosity,
high density)
• adaptations: streamlining

24. Adaptations to Physical
Conditions of the Ocean
Cold water
• hard to swim through (high viscosity,
high density)
• adaptations: streamlining

25. Adaptations to Physical
Conditions of the Ocean
Warm water
• adaptations: ornate plumage/
appendages to increase surface area

26. Adaptations to Physical
Conditions of the Ocean

27. Adaptations to Physical
Conditions of the Ocean
Salinity

28. Adaptations to Physical
Conditions of the Ocean
Salinity
• osmosis = movement of water
molecules through semi-permeable
membrane (osmos = “to push”);
• water molecules always move from
less concentrated solution to more
concentrated solution

29. Adaptations to Physical
Conditions of the Ocean

30. Adaptations to Physical
Conditions of the Ocean
High salinity

31. Adaptations to Physical
Conditions of the Ocean
High salinity
• low H2o
• dehydrating fish
• adaptations: drink lots of water,
secrete salts, small amount of urine

32. Adaptations to Physical
Conditions of the Ocean

33. Adaptations to Physical
Conditions of the Ocean
Low salinity

34. Adaptations to Physical
Conditions of the Ocean
Low salinity
• high H2o
• fish absorb water easily
• fish do not drink water, cells absorb
salts, large volume of urine

35. Adaptations to Physical
Conditions of the Ocean

36. Adaptations to Physical
Conditions of the Ocean
Dissolved gases: Oxygen

37. Adaptations to Physical
Conditions of the Ocean
Dissolved gases: Oxygen
• high oxygen adaptation: gills extract
dissolved oxygen from water
• low oxygen: fish can’t breathe the air
from the surface

38. Adaptations to Physical
Conditions of the Ocean
Dissolved gases: Oxygen
• high oxygen adaptation: gills extract
dissolved oxygen from water
• low oxygen: fish can’t breathe the air
from the surface

39. Adaptations to Physical
Conditions of the Ocean
Dissolved gases: Oxygen
• high oxygen adaptation: gills extract
dissolved oxygen from water
• low oxygen: fish can’t breathe the air
from the surface

40. Adaptations to Physical
Conditions of the Ocean

41. Adaptations to Physical
Conditions of the Ocean
Transparency

42. Adaptations to Physical
Conditions of the Ocean
Transparency
• sea water has high transparency;
allows sunlight to penetrate to about
1000 m
• adaptations: keen eyesight,
camouflage, countershading = fish are
dark on top, light on bottom

43. Thank you!