Water Circulation-Primary Productivity

Question 1

thermocline variation in relation to latitude

Answer 1

Temperature at the top layer is the highest (tropics)

- wider thermoclines

Question 2

strong summer thermocline

Answer 2

No vertical mixing

relatively difficult mixing and diffusion

Question 3

thermocline variation in relation to season

Answer 3

Stronger in summer, weaker in winter

Question 4

Weak winter thermocline

Answer 4

Full vertical mixing

- Has implications for ocean productivity and upwelling

Question 5

Upwelling

Answer 5

The movement of deep, cold, and nutrient-rich water to the surface

Question 6

What does upwelling cause?

Answer 6

Nutrients + light near surface = photosynthesis

- surface currents, more plants, animals, fisheries

Question 7

Why does upwelling matter?

Answer 7

Permanent upwelling areas support the richest fisheries

• 1% sea surface
• 50% of world fisheries

Question 8

ENSO

Answer 8

El Nino Southern Oscillation

• Starts ~December
• Periodic (irregular) phenomenon
• Influences weather; large scale

Question 9

continental margin

Answer 9

Made up of continental shelf, continental slope and continental rise

Question 10

pelagic zone

Answer 10

open water above the ocean floor

Question 11

neritic zone (ocean)

Answer 11

Everything that is on top of the continental shelf

Question 12

oceanic zone (ocean)

Answer 12

Everything beyond the continental shelf

Question 13

water column

Answer 13

Vertical Zones of the ocean with changing conditions as depth increases.

Question 14

layers of the water column

Answer 14

1. Epipelagic (200 m)
2. Mesopelagic (1,000m)
3. Bathypelagic (4,000m)
4. Hadal-pelagic (>6,000 m)

Question 15

depth & conditions of epipelagic zone

Answer 15

0-200m; Photosynthesis

Question 16

depth & conditions of mesopelagic zone

Answer 16

1,000m; Some light but no photosynthesis

Question 17

depth & conditions of bathypelagic zone

Answer 17

4,000 m; no light

Question 18

Depth & Conditions of Hadalpelagic zone

Answer 18

> 6,000 m; no light

Question 19

Benthos

Answer 19

Seafloor creatures

Question 20

Pelagos

Answer 20

Water column creatures

Question 21

Two groups of pelagos organisms

Answer 21

1. Nekton; swim against currents
   - secondary producers
2. Plankton; drifting
   - primary producers

Question 22

What are the limiting factors for phytoplankton photosynthesis?

Answer 22

• Light

- Nutrients (phosphate, nitrate, iron and silicon)

Question 23

Gross primary productivity

Answer 23

Total organic carbon produced by photosynthesis

Question 24

Net primary productivity

Answer 24

Total organic carbon minus the carbon used for respiration

Question 25

Compensation depth

Answer 25

Depth where photosynthesis = respiration meaning net productivity = 0

Question 26

What type of growth do phytoplankton show?

Answer 26

Exponential growth | - due to asexual reproduction

Question 27

temperate latitude and phytoplankton growth

Answer 27

- two phytoplankton blooms (more intense in spring) | - limited by availability of light or nutrients (never both)

Question 28

Polar latitudes and phytoplankton growth

Answer 28

- one bloom - limiting factor is sunlight - lots of nutrients because of upwelling - vertical mixing ( weak thermoclines)

Question 29

Tropical latitudes and phytoplankton growth

Answer 29

- permanent thermocline as a barrier for vertical mixing | - nutrients are limiting factor

Question 30

Micro plankton size

Answer 30

20-200 um

Question 31

Nano plankton size

Answer 31

2-20 um

Question 32

Three groups of phytoplankton

Answer 32

1. Diatoms 2. Dinoflagellates 3. coccolithophores

Question 33

Diatoms

Answer 33

- microplankton; unicellular usually forming chains - cell wall made of silica - benthic habitat

Question 34

Dinoflagellates

Answer 34

- microplankton With two flagella | - thick cellulose theca

Question 35

Coccolithophores

Answer 35

nanoplankton - highly reflective - removes co2 from atmosphere

Question 36

Describe the halocline | quiz question

Answer 36

Areas of water with a sharp change in salinity

Question 37

If you are on the coast of Peru, what happens to the thermocline during ENSO in comparison to La Nina? Any differences? (Quiz question)

Answer 37

Thermocline during ENSO affects weather patterns and upwelling (regional) and La Nina returns conditions back to normal