Chapter 2: Primary Production

Question 1

Name all the different sizes of plankton

Answer 1

Femtoplankton - 0.02-0.2um
Picoplankton - 0.2-um
Nanoplankton - 2-20um
Microplankton - 20-200um
Mesoplankton - 0.-20mm
Macroplankton - 2-20cm
Megaplankton - 0.2-2m

Question 2

Describe Diatoms

Answer 2

Class Baccilariophyceae

• silica frustule
• no visible flagella
• centric or pinnate
• pelagic/benthic forms
• solitary/colonial

Question 3

Describe dinoflagellates

Answer 3

Class Dinophyceae

• 2 visible flagella
• cellulose plates
• typically solitary
• reproduce via mitosis, no size change
• harmful algae in blooms
• some bioluminescent
• many heterotrophs
• endosymbiotic zooxanthellae (symbiotically work with other species, illumination etc.)

Question 4

Describe Haptophyceae

Answer 4

Naked cells, mainly solitary forms

Motile: 2 flagella, 1 haptonema

Question 5

Describe Coccolithophores

Answer 5

Covered in coccolits (small calcium plates)

-solitary w/ complex life cycles

Question 6

What is probably the most common phytoplankton in the ocean?

what does it contribute?

Answer 6

Prochlorophytes (a cyanobacteria)

• > 30-70% of Chl.a in open oceans
• > 30-80% of total ocean productivity

Question 7

Name the big 3 algal toxins and human health issues

Answer 7

• PSP (paralytic shellfish poisoning)
• NSP (Neurotoxic shellfish poisoning)
• DSP (Diarrhetic shellfish poisoning)

Question 8

Photosynthesis equation.

Answer 8

6CO(2) + 6H(2)O C(6)H(12)O(6) +6O(2)

Question 9

name 3 ways to measure primary production

Answer 9

1) from the reaction, measure changes in O2 or in CO2
2) Light/dark-bottle method, where you use a clear (photosynthesis) + opaque (respiration) bottle, and measures of oxygen are taken by winkler titration.
3) 14C method where radioactive carbon is added to the water sample, and tested for algae growth.

Question 10

Photosynthesis in the ocean is affected by:

Answer 10

• Radiation level
• Availability of nutrients
• Water mass properties

Question 11

In the light spectrum, what is the Photosynthetic Active Radiation (PAR) range?

Answer 11

the visible light spectrum, from 380-710nm

Question 12

name some systematic and unsystematic variations for solar radiation

Answer 12

systematic: with season, over the day.
unsystematic: cloud cover, vegetation, competition

Question 13

Light penetration in the water column depends on:

Answer 13

• water clarity (absorption, reflectance)

- wavelength (red colors are absorbed more rapidly than blue)

Question 14

Which law describes the attenuation of radiation?

Answer 14

Beer’s law

Question 15

Compensation depth

Answer 15

The depth in the water column where photorespiration = photosynthesis
(ie: primary productivity = 0)

Question 16

what are the four main nutrient salts?

Answer 16

Nitrate, Nitrite, ammonia and phosphate

Question 17

describe the phytoplankton community succession of temperate and tropical seas.

Answer 17

Temp:
small diatoms->large diatoms -> dinoflagellates
Trop:
coccolithophors and dinoflagellates dominate throughout the seasons, but minor diatom blooms are common.

Question 18

what factors are proposed to regulate the succession of phytoplankton?

Answer 18

• temperature
• changes in nutrient salt concentrations
• biological conditioning
• biological control

Question 19

What is the theoretical reason for ‘high nutrient low chlorophyl’ subarctic waters, and how does iron influence this?

Answer 19

• waters may not receive enough light
• too much grazing pressure
• not enough iron (iron is introduced from land, and may not reach these offshore areas)

Question 20

what is the typical elemental composition of an algal cell?

Answer 20

protein: 40%
carbohydrate: 40%
lipid: 15%
nucleic acid: 5%

Question 21

how is the ocean’s capability of acting as a ‘carbon sink’ being affected by global warming?

Answer 21

1) as the oceans warm, they have less capability of absorbing the CO2
2) As more CO2 is absorbed there will be a reduction of pH in the water, resulting in the process of ocean acidification.

Question 22

the main limiting inorganic nutrients are what?

Answer 22

• nitrogen
• phosphorus
• some areas iron

Question 23

what large-scale processes influence the rate of primary productivity in the ocean?

Answer 23

frontal systems, gyres, river plumes and coastal upwelling

they transport nutrient-rich waters to the sea surface