Modelling nitrogen and phosphorus recovery potential by Ulva fasciata

This study investigated the nitrogen and phosphorus uptake efficiency and recovery potential by the cosmopolitan macroalga <i>Ulva fasciata</i>. An equation to estimate biomass production, as well nitrogen and phosphorus recovery, by <i>Ulva</i> species is further proposed. Results showed that <i>U. fasciata</i> removed 99 % of nitrogen (NH₄-NO₃) and 22 % of phosphate dissolved in water. Tissue nitrogen, phosphorus and chlorophyll-<i>a</i> increased 73, 20 and 244 %, respectively, demonstrating rapid assimilation of nutrients fueling <i>U. fasciata</i>’s growth (5.69 % day^-1). The constructed equation correlating fresh weight and area showed that 0.21- and 11.35-tons ha^-1 year^-1 of phosphorus and nitrogen could be recovered and that 3.47 tons of dry biomass could be produced. Tissue data add to the understanding of physiological effects of nutrient availability in <i>U. fasciata</i>. The efficient removal of dissolved nitrogen and phosphorus represents an important ecosystem service with potential for production of value-added by-products.<br>