N, P and Si in Oceans - non-siliceous phytoplankton vs siliceous phytoplankton

http://www.nies.go.jp/gaiyo/bunya/aquaterra-e.html

Effects of Changes in Nutrient Ratios of River Water on Marine Ecosystems

As human activities increase, the inflowing of nitrogen (N) and phosphorus (P) into oceans is also augmented. On the other hand, the amount of silicon (Si) that flows into oceans tends to decrease since silicon settles and gets trapped in still bodies of water such as dam reservoirs. It is therefore likely that, in these conditions, non-siliceous phytoplankton (including the harmful red tide algae) can thrive better than siliceous phytoplankton, which are mostly harmless. Our research aims to clarify these ecological changes through ocean observation by ferry and ecosystem modeling.

http://db.cger.nies.go.jp/gem/sea/SE_Pacific/me.html

------------------------------
This study and approach confirms our views that Diatoms (siliceous phytoplankton) are good and Green, Blue Green Algae and Red Tides (non-siliceous phytoplankton)are not useful or are even harmful.