Methods in Oceanography

Question 1

microscopy

Answer 1

1mm - 3 micrometer

Question 2

Flow cam

Answer 2

1mm - 6 micrometer

Question 3

Flow cytometry

Answer 3

20 micrometer - 0.5 micrometer

Question 4

molecular barcoding problems

Answer 4

data base incomplete, DNA content variable among species/difficult to quantify

Question 5

what do you measure with biomass, bulk measurements

Answer 5

POC > 0.7 micrometer, Chl a > 0.7 micrometer

Question 6

POC measurement problems

Answer 6

Unspecific for photosynthetic organisms

Question 7

Concentration of Cal a depends on

Answer 7

irradiance, amount of nutrients present, composition and phytoplankton size

Question 8

What does an argo float measure?

Answer 8

Temperature, Salinity, Chl a, carbon, nitrate

Question 9

Remote sensing

Answer 9

Satellite sensors estimate cal a from irradiance leaving the water.

Question 10

How does remote sensing work?

Answer 10

Chl a absorbs sunlight in red and blue waves. The irradiance that leaves the water becomes greener, depending on the chl a concentrations.

Question 11

Remote sensing can also measure

Answer 11

Organic carbon pool, Photophysiology, composition

Question 12

bloom

Answer 12

increase in biomass above a treshold

Question 13

phenology

Answer 13

timing of periodic biological events as influenced by the environment

Question 14

Phases of a bloom

Answer 14

Start day, intensity, duration

Question 15

Limitations of remote sensing

Answer 15

Cloud an sea ice cover, high altitude in winter not measurable bc of low sun angles, Coastal not reliable due to detritus and sediments, satellites are expensive, no vertical profile, needs validation by in situ data

Question 16

Why not measure POC or chlorine a as indicator for primary production in the ocean?

Answer 16

POC can be zooplankton, chl a reflects composition and physiological changes, growth = loss, growth < loss, cal a concentration can change due to mixing.

Question 17

Gross primary production (GPP)

Answer 17

Total rate of organic carbon produced by autotrophs

Question 18

Respiration

Answer 18

Energy used for maintenance and growth (10-20% of GPP)

Question 19

Net Primary Production NPP

Answer 19

Total organic carbon production minus respiration of autotrophs

Question 20

Oxygen evolution, Winkler technique

Answer 20

Light bottle: respiration and photosynthesis, dark bottle: respiration –> measure amount of oxygen used

Question 21

disadvantage winkle technique

Answer 21

Inaccurate due to long incubation, includes respiration heterotrophs

Question 22

Carbon assimilation

Answer 22

add 14C labeled bicarbonate, measure 14C incorporated in organic carbon.

Question 23

Issues with 14c incorporation

Answer 23

Unnatural irradiance, unnatural irradiance, extracellular release of DOC ignored.

Question 24

active chlorophyll a fluoresence

Answer 24

Measure electron transport rate through photosystem 2

Question 25

Global ocean productivity is estimated by combining

Answer 25

Biomass, irradiance, in situ productivity vs irradiance measurements