Lecture 3 - Primary Production Flashcards
What percentage of total carbon captured by photosynthesis on the planet occurs in the sea?
50%
What percentage of the Earth’s carbon dioxide is cycled and stored through marine systems?
Over 90%
How can we measure where phytoplankton are located?
Looking at chlorophyll concentration across the planet from satellite images.
What percentage of primary production is produced by phytoplankton?
50%
Describe how carbon flow is linked to photosynthesis in phytoplankton.
- Phytoplankton photosynthesise in the surface layer, using nutrients.
- Organic matter from dying phytoplankton sinks, removing nutrients from surface waters.
- Photosynthesis can then carry on when layers are remixed.
What is primary production?
The fixing of carbon from an inorganic form to an organic form.
What is the term ‘carbon flow’ referring to?
The energy in the open oceans.
Name primary producers that are
a) Pelagic
b) Benthic
a) Pelagic = Phytoplankton
b) Benthic = Microalgae
How big are cyanobacteria?
1 micrometre in diameter
What is a holoplankton?
An organism that spends its whole life as a plankton.
What is a meroplankton?
An organism that spends only a part of its lifecycle as a plankton
What is a picoplankton?
A plankton that is 0.2-2 micrometers in diameter
What is a nanoplankton?
A plankton that is 2-20 micrometers in diameter?
What is a micro plankton?
A plankton that is 20-200 micrometers in diameter.
What is a mesoplankton?
A plankton that is 200-1000 micrometers in diameter.
What is phytoplankton in Greek?
Phyton = plant Planktos = drifter
Describe the structure of diatoms.
Small, single-cellular protists.
Cell wall called a frustule, made up of silica.
Describe the growth of diatoms.
Divide asexually up to 4 times a day - grow fast.
Do diatoms reproduce sexually?
They normally produce asexually, although sexual reproduction has been observed.
Describe algal blooms of diatoms.
Cause harmful algal blooms by producing domoic acid that causes shellfish poisoning.
Describe the structure of dinoflagellates.
Unicellular protists.
Have a flagellum in a groove around the edge of their main body.
What are zooxanthellae?
A type of dinoflagellate that lose their flagella when taken up by a coral host.