Nutrients In Class

Question 1

Nitrate Conc is 6 and phosphate is 0.3. Which nutrient will run out first and how much left of the other?

Answer 1

Use redfield ratio, phosphate run out first
Have 1.2 nitrate left

Question 2

Which line is from the spring tide?

Answer 2

The line with saltier surface and fresher depth
Should have a more homogenized profile

Question 3

Do you expect upwelling at this time?
Fresher inside and saltier outside

Answer 3

FW will flow out of the inlet and saltier water flow in below and cause upwelling

Question 4

Why is 16:1 ratio so close in the ocean

Answer 4

Denitrification pulls N down where O2 is low – no dependence on N:P ratio (lowers N:P ratio)
Nitrogen fixation increases N:P ratio – energy intensive (only happens when N deficit)

So phytoplankton essentially create the 16:1 conditions for themselves, they control the ratio in the ocean

Question 5

During a stratified summer period
after the spring bloom, where in
the water column do we expect
to see near-zero nutrient
concentrations?

Answer 5

It will occur all the way down to the compensation depth

Question 6

When is a fall bloom likely to start?

Answer 6

When the MLD is at the summer Dc (nutricline) and will continue until the MLD falls below the Dcr

Question 7

What causes a PAR profile to drop and then increase again at a deeper depth?

Answer 7

This is caused by a shadow of the boat or the clouds
Decreases PAR when that happens then moves and increases again.

Question 8

How do you find the euphotic zone on a partly shaded PAR profile?

Answer 8

You can log transform the graph so it linearizes it and from there extrapolate to the surface