Ocean Marine Ecosystems

Question 1

What are two ocean ecosystems?

Answer 1

-Open ocean
-Vertical zones

Question 2

What is the most productive ecosystem?

Answer 2

The open ocean

Question 3

How much of the world’s oxygen is produced by the ocean?

Answer 3

70%

Question 4

How many tonnes of phytoplankton are produced a year?

Answer 4

20 billion tonnes a year

Question 5

How deep can light penetrate clear ocean water?

Answer 5

Approx. 100 m

Question 6

Is ocean productivity uniform around the globe?

Answer 6

No, there is uneven latitudinal distribution

Question 7

What does photosynthesis depend on?

Answer 7

Depends on the availability of light

Question 8

What is the formula for compensation depth?

Answer 8

P = R
Production is equal to respiration

Question 9

When does productivity occur?

Answer 9

Only when rates of photosynthesis exceed rates of respiration

Question 10

Is growth and production greatest at the surface?

Answer 10

No, due to photo-inhibition
-Phytoplankton do not continue to increase growth with increased radiation

Question 11

What factors regulate production?

Answer 11

Macronutrients
Micronutrients

Question 12

What are examples of macronutrients?

Answer 12

C Carbon
H Hydrogen
O Oxygen
Ca Calcium
Mg Magnesium
Na Sodium
, K,
S Sulfer
, Cl
P, N,
Si Silicon

Question 13

What are examples of micronutrients?

Answer 13

Fe,
Mn (Manganese)
Cu, Zn,
B (Boron)
Mo (Molybdenum (N fixation), V, Co, (B12)

Question 14

What nutrients are abundant?

Answer 14

C, H, O

Question 15

What nutrients are in limited supply?

Answer 15

P, N, Si

Question 16

What are intermediate productivity waters called?

Answer 16

Mesotrophic waters

Question 17

What are high productivity waters called?

Answer 17

Eutrophic

Question 18

What are waters of low productivity called?

Answer 18

Oligotrophic

Question 19

How much carbon does oligotrophic have?

Answer 19

<100 gC-2 year-1

Question 20

How much carbon does mesotrophic have?

Answer 20

100 - 300gC-2 year -1

Question 21

How much carbon does eutrophic have?

Answer 21

300 - 500 gC-2 year -1

Question 22

How much carbon does hypertrophic have?

Answer 22

> 500 gC-2 year -1

Question 23

What further restricts the productive zone?

Answer 23

Nutrient limitation

Transport is downward, depleting the surface layers

Question 24

What effects the rate of sinking of organic matter?

Question 24

What effects the rate of sinking of organic matter?

Answer 24

-Rate of sinking decreases as it encounters the cold, dense water of the thermocline

Question 25

What happens in the thermocline?

Answer 25

-Material decays (oxidises) at the thermocline, which strips O2, out of the water and returns nutrients to the sea -Cold, nutrient-rich water of the thermocline is returned to sunlit surface waters by way of upwelling

Question 26

What is Liebig's Law of the Minimum?

Answer 26

-Growth is not controlled by the total of all resources available -Growth is controlled by the most scarce resource (limiting factor)

Question 27

What are the major control mechanisms of primary production?

Answer 27

-The photosynthetic light limitation -Amt. of dissolved inorganic nutrients -Marine bacteria and nutrient recycling -Zooplankton grazing -Vertical mixing issues

Question 28

What does HNLC stand for?

Answer 28

High Nutrients areas with Lower than expected Chlorophyll is produced

Question 29

What are HNLC regions?

Answer 29

High nutrient areas (eg. Nitrogen N and Phosphorous P) however there is lower than expected chlorophyll is produced there

Question 30

What are examples of HNLC areas?

Answer 30

Santa Cruz, CA Big Sur, CA,

Question 31

What depths is the pelagic and epipelagic zones?

Answer 31

Up to 200 m (includes photic zone)

Question 32

What depths are the mesopelagic zone?

Answer 32

200m - 1000m

Question 33

What depths are the bathypelagic zone?

Answer 33

1000m - 4000m

Question 34

What depths are the abyss alpelagic zone?

Answer 34

4000m downwards,

Question 35

What are neritic zooplankton?

Answer 35

Spend most of time in coastal areas

Question 36

How are zooplankton classified?

Answer 36

According to where they live

Question 37

What are the areas where zooplankton live?

Answer 37

-Euphotic (Epiplanktonic, Pleuston, Neuston) -Disphotic (Meroplanktonic) -Aphotic (Infra and Bathyplanktonic)

Question 38

Describe Physalia (plustonic organism)

Answer 38

-Colonial cnidarian with gas filled siphon -Feeds on zooplankton and small fish using trailing tentacles

Question 39

Describe valella (plustonic organism)

Answer 39

-Colonial cnidarian with air siphon in its upright sail -Gas filled structure to keep it buoyant

Question 40

Describe neustonic organisms

Answer 40

-Nudibranch swims upside down -Ingest air into digestive tract -Ingests nematocysts- passes to papillae on upper surface (inflicts painful stinging) (Gaucus and Janthina)

Question 41

What is another way to classify zooplankton?

Answer 41

On how long they live in plankton

Question 42

How long holoplanktonic stay as plankton?

Answer 42

Entire lifetime

Question 43

How long do meroplanktonic plankton live as plankton?

Answer 43

Only for a period of time

Question 44

How long do tchoplanktonic plankton live as plankton?

Answer 44

Accidental members

Question 45

Describe holoplankton

Answer 45

-Spend all their life in plankton -Arrow-worms, jellyfish, sea-gooseberries, crustacea

Question 46

Describe meroplankton

Answer 46

-Larval stages of organisms -Marine worms, molluscs, echinoderms, crustaceans and fish -Buoyant fish eggs Important source of food for oceanic birds

Question 47

What are halobates?

Answer 47

-Only insect, a water strider int he sea -Cannot tolerate immersion -Uses surface water tension to stay afloat -Feeds on organisms on surface , cnidarians and copepods

Question 48

What other organisms live in ocean environments?

Answer 48

-Bacteria and Heterotrophic protozoa -Detritivores feeding on organic material -Occur in thousands much greater than in underlying waters