primary production

Question 1

what is primary production?

Answer 1

production of chemical energy in organic compounds by living organisms

Question 2

1. entry point of energy into food webs
2. Major biogeochemical transformation of carbon

Answer 2

the importance of primary production

Question 3

primary production is primarily done by

Answer 3

phytoplankton

Question 4

is primary production mostly on land or in the ocean ?

Answer 4

the land

Question 5

microalgae, responsible for >95%
of photosynthesis in the ocean

Answer 5

Phytoplankton

Question 6

coastal, important in nutrient rich
(often cold) regions

Answer 6

Macroalgae

Question 7

coastal, highly productive but
restricted to very shallow (often tropical) waters

Answer 7

Seagrasses

Question 8

small phytoplankton are in what kind of regions?

Answer 8

oligotrophic (low nutrients) regions

Question 9

large phytoplankton are in what kinds of regions?

Answer 9

eutrophic (high nutrient) regions

Question 10

describe a diatom

Answer 10

5 – 200 um (human hair ~100 um)
* Silicate Cell‐wall
* ‘Pill‐box’ shape

Question 11

centric diatoms…

Answer 11

may be circular, triangular, or rectangular and have radial symmetry

Question 12

penate diatoms…

Answer 12

elongated with surface markings at right angles to the long axis, an arrangement called bilateral symmetry.

Question 13

Diatoms generally _______the phytoplankton community whenever there are
lots of nutrient inputs

Answer 13

dominate

Question 14

what are some examples of cyanobacteria

Answer 14

Picoplankton & Trichodesmium

Question 15

Very Abundant, esp. in Open Ocean
 Common in low productivity, nutrient limited regions
 Synechococcus, Prochlorococcus

Answer 15

picoplankton

Question 16

2 flagella (motile)
* 5 – 200 um
* Cell wall of cellulose plates (wood)
* Diverse “life styles”:
Autotrophs, Heterotrophs, Parasites, Symbionts
* Harmful Algal Blooms (HABS)
* Zooxanthellae: symbionts in corals

Answer 16

dinoflagellates

Question 17

Largest primary producers in the sea (seaweeds, kelp)
* Typically grow on rocky substrates
* Generally restricted to coastal zone

Answer 17

macroalgae

Question 18

what are some examples of macroalgae ?

Answer 18

kelp and sargassum weed and green algae

Question 19

sea grasses are

Answer 19

True (flowering) plants
* Shallow, clear habitats (need high light)

Question 20

what are two examples of seagrass?

Answer 20

eel grass and turtle grass

Question 21

what are the 2 main factors of controlling primary production?

Answer 21

nutrient availability and light

Question 22

which has more visible light, the open ocean or coastal water?

Answer 22

COASTAL WATER. This is because coastal areas often contain more suspended particles and phytoplankton, which can reflect and scatter light. In contrast, the open ocean, especially in deeper regions, may absorb more light, leading to lower visibility. However, the specific conditions can vary widely depending on factors like location, time of year, and water clarity.

Question 23

why are nutrients found at lower concentrations in surface waters than at depth?

Answer 23

Much less abundant in
the ocean than on land
 High consumption in the
surface layer
 Decaying matter sinks to
depths below the surface
zone
 Can only be returned to
sunlit area by upwelling

Question 24

upwelling = _____ productivity

Answer 24

HIGH

Question 25

deep mixing = _________ productivity

Answer 25

HIGH

Question 26

permanently stratified = _______ productivity

Answer 26

LOW

Question 27

low light or low iron = _______ productivity

Answer 27

LOW

Question 28

Which organisms are responsible for primary
production in the ocean?

Answer 28

Phytoplankton: Diatoms, Coccolithophores,
Cyanobacteria
Macroalgae and Seagrasses

Question 29

Why do rates of primary production vary in
the ocean?

Answer 29

Nutrients, Light

Question 30

How do rates of primary production vary in
the ocean?

Answer 30

Upwelling and Temperate/Subpolar regions
have high primary production, tropics have low