1

1

Characteristics of All Living Things

Contain matter in a highly organized state

Capture, store and transmit energy; all organisms require energy

Capable of reproduction

Change through time and adapt to their environment

2

Evolution and Life in the Ocean

Life originated in the ocean.

Organisms have evolved over the last 4 billion yearsthrough the process of natural selection.

The environment favors individuals that are welladapted. Microorganisms are the most successful lifeforms.

Sometimes, catastrophic events wipe out many organisms, regardless of adaptation.

2

3

Linnaeus developed the system used to name and classifyorganisms

System is based on a hierarchy: kingdom, phylum, class,order, family, genus and species

Uses scientific names for organisms; a species consists ofthe genus name combined with a trivial name.

Formal names are in Latin; common names are in locallanguages

Classification of Oceanic Life

4

The six (or five)kingdoms of organisms

Classification of Living Things

3

5

The Three Domains of Life

6

Classification of Oceanic Life

4

7

8

Classification of the Marine Environment

5

9

10

Benthic environment - divided by depth into:intertidal zone, sublittoral zone, bathyal zone,abyssal zone, and the hadal zone.

Pelagic environment - divided broadly into:neritic zone and oceanic zone, and morespecifically into the epipelagic, mesopelagic,bathypelagic, abyssalpelagic, andhadalpelagic zones.

Benthic (bottom) and Pelagic(water column) Environments

6

11

Zones Based on Depth of LightPenetration

Photic zone - depth where light issufficient for photosynthesis.

Dysphotic zone - illumination is too weakfor photosynthesis.

Aphotic zone - no light from the surfacebecause it is all absorbed by the waterabove.

12

Major Lifestyles

Plankton - free floating organisms;phytoplankton and zooplankton

Nekton - swimmers Benthos - bottom dwellers (on, in or

attached) Epifauna - live on the bottom (attached or

free) Infauna - organisms that live in or burrow in

the sediment

7

13

Physical and Biological Factors

A proper balance of physical and biological factors isimportant for the success of each organism andthe community.

Different organisms have different tolerances for specific factors.

Steno- is a prefix meaning “narrow”. It describes organisms that have narrow tolerances for specificfactors

Eury- is a prefix meaning “wide”. It describes organismsthat have wide tolerances for specific factors

14

Limiting Factors

Limiting factor - physical or chemical factorin the environment that can limit or harmorganisms if present at levels that are too large, too small or too extreme.

Any factor required for life can become a limiting factor.

8

15

Physical Factors AffectingMarine Life

Any aspect of the physical environment that affects organisms is aphysical factor.

The most important physical factors for marine organisms are:

light dissolved gases

temperature acid-base balance

salinity hydrostatic pressure

nutrients buoyancy

16

Figure 13.9

9

17

Temperature

Temperature - controls distribution, degree ofactivity and reproduction of an organism

Ectotherms - cold-blooded organisms; bodytemperature determined by environmentalconditions (all marine organisms except birdsand mammals)

Endotherms - warm-blooded organisms;maintain near-constant body temperature (birdsand mammals)

18

Temperature

10

19

Biogeochemical Cycles

Cycles of elements that are important in lifeprocesses.

Carbon - present in all organic molecules

Nitrogen - found in proteins and nucleic acids

Phosphorus and silicon – found in rigid parts of organisms

Iron and trace metals - used for electron transport

20

Figure 13.8

11

21

Physical Factors AffectingMarine Life

22

Biological factors also affect organisms in the ocean.

Some biologic factors that affect marine organisms:

• feeding relationships

• crowding

• metabolic wastes

• defense of territory

Biological Factors

12

23

Organisms in the ocean rely on these processes formany life functions.

Diffusion is mixing due to random molecular movements.

Osmosis is diffusion of water through a membrane

Active transport is the transport of a substance against a concentration gradient. Active transport requires energyinput.

Diffusion, Osmosis, and ActiveTransport

24

Diffusion, Osmosis, and Active Transport

13

25

Marine Ecology

Ecology: Inter-relationships between the physical andbiological aspects of the environment

Marine organisms live in communities - groups ofinteracting producers, consumers, and decomposerssharing a common living space

Ecosystem - total environment including the biota (all livingorganisms) and the non-living physical and chemicalaspects

Symbiotic relationships are common in the ocean. Mostforms of marine life are actively involved in them

26

Organisms Within Communities

Terms for describing organisms and theirenvironments:

Habitat - an organism’s physical location in itscommunity

Niche - an organism’s role in the community

Biodiversity - the variety of species in a given area

14

27

Symbiosis is the close interaction of the lives oftwo species.

Types of symbiotic interactions:

Mutualism - both organisms benefit in these relationships.

Commensalism - one organism benefits, the other is nothelped or harmed.

Parasitism - one organism benefits, but the other isharmed.

Symbiotic Interactions

28

Marine Communities

The J-shaped curve represents the growth of a population withoutcompetitors for food or space. The S-shaped curve represents populationgrowth when the population encounters environmental resistance.

15

29

Changes in Marine Communities

Marine communities change through time. Changes canoccur slowly due to climate cycles or seafloor spreading,or quickly due to factors such as volcanic eruption.

A climax community is a stable, long establishedcommunity.

If a climax community is disrupted, it may be restoredthrough the process of succession.

30Competition can occur among members of the same species, orbetween members of different species.

Competition

16

31

Examples of Marine Communities

Rocky intertidal Seaweed Beach Salt marsh and estuary Coral reef Open ocean Deep sea floor Hydrothermal and cold vents

32

Intertidal Communities

Generally arranged in distinctive bands orvertical zonation

Zonation reflects amount of time the area issubmerged and ability of organisms to surviveexposure.

Benthic communities also vary based onsubstrate (bottom material). Some organismsare adapted to rocky, sandy, or muddy seabottoms.

17

33

HIGH TIDE

LOW TIDE

34

Rocky Intertidal Communities

The most important physical factor in a rocky intertidal community is therise and fall of tides.

18

35

Seaweed Community Seaweed provides protection and high productivity to the

animals that live in the communities

A complex interaction among kelp, sea urchins, and seaotters controls the kelp community

Sea urchins feeding on kelp detach them from theirholdfast and devastate the kelp beds

Sea otters feed on sea urchins and control the size oftheir population

Where sea otters abound, sea urchins are few, kelpbeds thrive and sea otters feed mainly on fish.

Where sea otters are few, sea urchins abound andkelp bed are thin. Sea otters then mainly eat seaurchins.

36

Sand and Cobble Beach Communities

Beaches are a demanding physical environment for organisms.

19

37

Salt marshes and estuaries are rich innutrients, but organisms must cope withfluctuating salinity in theseenvironments.

Salt Marshes and Estuaries

38

Coral Reefs

More than one millionspecies inhabit coral reefecosystems.

20

39

Open Ocean

Consumers in the open ocean depend on the productivity oforganisms in the water column above.

40

The deep-sea floor is dark, cold, and highly pressurized, yet many speciesincluding the blind tripod fish are found in this harsh environment.

The Deep-Sea Floor

21

41

Many chemosynthetic organisms are found near hydrothermal vents andcold seeps.

Hydrothermal Vent and ColdSeep Communities

42

A Pacific coast tidepool.

Organisms rely on boththe physical andbiological factors intheir environment forsurvival.