Quote:
Originally Posted by Subsea
Macro absorb nutrients in the same ratio. It is called the Redfield Ratio at 106/16/1 of carbon/nitrogen/phosphate
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That's not actually correct. The ratio does variy from place to place somewhat, & in any case the redfield ratio is not a regulator for how much of each nitrient any particular organism takes up.
The atomic ratio C:N:P in phytoplankton is 106C:16N:1P, while bethnic plants (mean of 92 species) on average have a somewhat higher ratio of 550C:30N:1P. These ratios indicate that many seaweeds are more prone to N limitation than phytoplankton.
The ratio of two nutrients that is required for maximal growth of a seaweed is called the optimum ratio. As stated above, the average N:P ratio for seaweeds is 30N:1P
with a range from 10:1 to 80:1
http://sailing-sea-farm.com/onewebme...v%C3%A6kst.pdf
Analysis of the annually-averaged 2001–2010 monthly nutrient data from 13 stations in the Venice Lagoon (Italy) shows that the concentrations of dissolved nitrogen (N) species, measured as total dissolved N (TDN), have increased over time while that of phosphorus (P) species, measured as total dissolved P (TDP) have decreased. During the study period, the TDN/TDP ratio in the lagoon rose from about 46:1 to 100:1 (by atoms), a level at which the growth of benthic macroalgae is favored over that of sea grasses.
http://levin.ucsd.edu/people/photos/...V180_33-41.pdf