Intro to oceans - Hilary online test compilation C - Flashcards in University Marine Science

1. Which IS NOT a common mechanism for removal of the dissolved minor and trace elements from seawater?

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Measuring chlorophyll concentrations is used to track zooplankton
Net nutrient removal is seen in the sunlit surface waters where the rate of photosynthesis exceeds the rate of respiration.
At depths where light to too low, respiration dominates and changes in the concentration of dissolved nutrients is dominated by an increase in their concentration.
An increase in the turbidity (presence of particles)of seawater, reduces the depth to which sunlight can penetrate

The attraction of organisms to a single location in the upper sunlit layers of the ocean
The formation of large particles from smaller particles by activities such as zooplankton grazing
The disturbance of organisms by particulate matter
The formation of lots of small particles in a small space due to turbulence

The residence time of an element in seawater can be estimated by dividing its mass in the ocean by its annual input from rivers.
The major ions in seawater have a residence time longer than average ocean mixing time.
That the chemical composition of the oceans is in steady state means that the rate of addition of dissolved constituents to seawater is balanced by their rate of removal, so that their concentrations do not change significantly with time.
A constituent with an oceanic residence time of 100 years will be uniformly mixed throughout the oceans