View Single Post
Old 02/12/2018, 10:21 PM   #4
Registered Member
Twinfallz's Avatar
Join Date: Aug 2016
Posts: 527
Originally Posted by Subsea View Post
Macro absorb nutrients in the same ratio. It is called the Redfield Ratio at 106/16/1 of carbon/nitrogen/phosphate
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

Analysis of the annually-averaged 20012010 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.

Twinfallz is offline   Reply With Quote