Nutrients and Biological Oceanography

Question 1

What are plankton?

Answer 1

Organisms that are unable to control their position against the action of currents

Question 2

What are the three sizes of phytoplankton with examples?

Answer 2

Ultraplankton : < 2 micro metres - hetretrophic bacteria, autotrophic and cyanobacteria

Nanoplankton : 2-20 micro metres - coccoliths, silica flagellates

Microplankton : 20-200 micro metres - diatoms and radiolaria

Question 3

What are zooplankton?

Answer 3

Limited in movement but are transported by currents

Question 4

What are nekton?

Answer 4

Animals that can control their movement and swim against currents

Question 5

What happens if Photosynthesis>Respiration?

Answer 5

Organic matter is produced

Question 6

What happens if Respiration>Photosynthesis?

Answer 6

Water loses Oxygen

Question 7

What are the 5 classifications of elements in seawater? (that aren’t helpful for looking at processes in the ocean)

Answer 7

1. Major
2. Minor
3. Trace
4. Conservative
5. Non-Conservative

Question 8

What is the Red Field Ratio?

Answer 8

106 C: 16 N: 1 P

Question 9

What is a bio-limiting element? (+ examples)

Answer 9

One that has total depletion in surface waters due to biological uptake (N, P, Si (+/- Cd, Zn, Ge))

Question 10

What is a bio-intermediate element? (+ examples)

Answer 10

A component that has a patchy distribution but rarely do their concentrations go to zero in the surface waters
(Ca, C, Sr, Cu, Se, Ba, Ra, CO3-)

Question 11

What is a bio-unlimited element? (+ examples)

Answer 11

Near vertical when salinity is considered. No affect of biology. Includes major elements. Have a long residence time and are unreactive
(Na, Mg, K, Cl)

Question 12

What is a scavenged element? (+ examples)

Answer 12

One with a higher profile in the surface waters than the deep waters (Pb)

Question 13

What are the three main nutrients looked at in seawater?

Answer 13

Nitrate, Phosphorus and Silica

Question 14

Which ocean has the least amount of nutrients?

Answer 14

The Atlantic

Question 15

Give some information about Phytoplankton

Answer 15

Unicellular, photosynthetic, some are hetertrophs

Question 16

Give some information about Coccolithophorids

Answer 16

Calcareous photoautotrophs (CaCo3), flagella, absorb Organic matter, found in warm open ocean waters

Question 17

Give some information about Diatoms

Answer 17

Siliceous photoautotrophs, radial or penate frustules, divide to reproduce, abundant in cold nutrient rich near shore waters, produce siliceous oozes at the poles

Question 18

Give some information about Dinoflagellates

Answer 18

Organic walled, auto and hetrotrophic, flagella, can cause red tides, not part of the sediment, single celled, found in nutrient poor water

Question 19

Give some information about Bacteria

Answer 19

Photoautotrophic cyanobacteria and other heterotrophs

Question 20

Give some information about Radiolaria

Answer 20

Silica walls, glass like exoskeletons, accumulate when they die to produce siliceous oozes on the seafloor at the equator

Question 21

Give some information about Foraminifera

Answer 21

Carbonate shells, 20um-a few cm in size, worldwide distribution, able to tolerate a range of salinity

Question 22

What are the two main reasons for seasonal variations in primary productivity?

Answer 22

1. Monsoon Rains

2. Upwelling and El Nino

Question 23

What is key for linking the Ocean and the Atmosphere System?

Answer 23

Ekman Spiral!

Question 24

Explain High Nitrate Low Chlorophyll (HNLC)

Answer 24

It occurs where there is a lot of nitrate that usually limits (e.g. the Antarctic) but there still isn’t a lot of productivity and there isn’t a good source of Iron (Fe) from the land via rain off… therefore Iron could be the limit to primary productivity