The ulvoid green alga Ulva lactuca was studied to determine its potential as a natural solution to bioaccumulate nitrogen and phosphorus from large, urban bodies of water and coastal watersheds. Specifically, a seaweed farm will be used to remove nitrogen and phosphorus (along with other pollutants and hard metals) from San Diego Bay, by cultivating the macroalga Ulva lactuca. To test the feasibility of using U. lactuca for this purpose, U. lactuca was grown at the Coastal and Marine Institute Laboratory (CMIL) in a series of eighteen small indoor tanks under different salinity and nutrient concentrations for six weeks. The effects of orthogonal combinations of different salinities (15 and 35 psu) and nutrient additions to the seawater (low, medium and high) on U. lactuca growth, photosynthesis, and on its ability to uptake nitrogen and phosphorus from the seawater were monitored. My results found that while U. lactuca survived and grew in all combinations of salinity and nutrients, steady-state photosynthesis, light harvesting and growth were all affected by variation in salinity and nutrient concentrations. Specifically, low salinity and the absence of nutrient input generally negatively affected U. lactuca photosynthesis and growth, while high salinity and medium levels of nutrients generally.
PI: Matthew Edwards; firstname.lastname@example.org