Oceanography Week 9
1. What's so good about life in the oceans?: 1. stable environment - temperature
2. lots of habitats
3. the easy life: buoyancy and floatation
4. mobility - easy to move around
5. access to stuff - oxygen and nutrients
6. transparent: sunlight, finding food, mate, etc.
2. three things are needed for productivity in the oceans: 1. Sunlight
2. Nutrients
3. Habitat
3. factors influence the amount of sunlight in the oceans: 1. Water depth
2. Turbidity - sediment
3. Season
4. Sea ice
4. Discuss the timing of solar energy, nutrients and phytoplankton biomass in
temperate latitude oceans.: In the spring as the sun rises higher, surface waters continue to warm which
1/4
, leads to strong seasonal thermocline, preventing vertical mixing. The nutrients depleted from surface waters can't be
replaced by deeper waters thus the phytoplankton population remains low. The phytoplankton become scarce in late
summer. When solar radiation diminishes surface temperature drop and summer thermocline breaks down. Nutrients
return to surface layer as increased wind strength mixes surface waters with deeper waters. There is a fall bloom of
phytoplankton.
5. How does productivity change with latitude: The tides are smaller closer to the equator so
there is less upwelling.
6. What is the "Redfield Ratio" and why worry about it?: The Redfield ratio or Redfield
stoichiometry is the atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton and throughout the
deep oceans. This empirically developed stoichiometric ratio was originally found to be Carbon: Nitrogen: Phosphorus
= 106:16:1
7. Why are continental shelf areas so productive?: Continental shelf areas cover about 15% of
ocean area but count for 50% of oceanic primary productivity for two main reasons. Nutrients recycle from the bottom
in shallow, well mixed shelf waters and nutrients runoff from land, a major source of Phosphorus.
8. What three ways can nutrients be brought up into the photic zone?: 1. Coastal
upwelling
2/4
1. What's so good about life in the oceans?: 1. stable environment - temperature
2. lots of habitats
3. the easy life: buoyancy and floatation
4. mobility - easy to move around
5. access to stuff - oxygen and nutrients
6. transparent: sunlight, finding food, mate, etc.
2. three things are needed for productivity in the oceans: 1. Sunlight
2. Nutrients
3. Habitat
3. factors influence the amount of sunlight in the oceans: 1. Water depth
2. Turbidity - sediment
3. Season
4. Sea ice
4. Discuss the timing of solar energy, nutrients and phytoplankton biomass in
temperate latitude oceans.: In the spring as the sun rises higher, surface waters continue to warm which
1/4
, leads to strong seasonal thermocline, preventing vertical mixing. The nutrients depleted from surface waters can't be
replaced by deeper waters thus the phytoplankton population remains low. The phytoplankton become scarce in late
summer. When solar radiation diminishes surface temperature drop and summer thermocline breaks down. Nutrients
return to surface layer as increased wind strength mixes surface waters with deeper waters. There is a fall bloom of
phytoplankton.
5. How does productivity change with latitude: The tides are smaller closer to the equator so
there is less upwelling.
6. What is the "Redfield Ratio" and why worry about it?: The Redfield ratio or Redfield
stoichiometry is the atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton and throughout the
deep oceans. This empirically developed stoichiometric ratio was originally found to be Carbon: Nitrogen: Phosphorus
= 106:16:1
7. Why are continental shelf areas so productive?: Continental shelf areas cover about 15% of
ocean area but count for 50% of oceanic primary productivity for two main reasons. Nutrients recycle from the bottom
in shallow, well mixed shelf waters and nutrients runoff from land, a major source of Phosphorus.
8. What three ways can nutrients be brought up into the photic zone?: 1. Coastal
upwelling
2/4
