Role of Benthic Plants in Fertilized Estuary

A study to elucidate the productivity contribution of benthic macrophytes in a fertile estuary was undertaken. Methods for utilizing C¹⁴ uptake as a productivity monitor of benthic plants are described. Both phytoplankton and macrophyte productivity determinations were made at various distances from a small sewage outfall, and the effect of nutrients on the phytoplankton and seaweeds was observed. It was also observed that the benthic flora was a better indicator of nutrient enrichment, because there was a uniform gradient of productivity stimulation away from the outfall. The phytoplankton showed erratic values at various distances from the outfall due to mixing in and out of the fertilized zone. It is proposed that a productivity model such as the Baule-Mitscherlich relationship can be used to predict the photosynthetic response of algae due to a combination of nutrients. This model will allow for the concept of multiple limiting nutrients in nature.