example the wall can retain 2 u00d7 3 u00d7 5 u00d7 10 u00d7 15 u00d7 20 u00d7 30 u00d7 40 u00d7 50 u00d7 70 u00d7 100 u00d7 200 u00d7 500 u00d7 1000 u00d7 or more organisms than water soluble nutrients by mass concentration or volume the prototype can be tested in a 3 million gallon closed water environment at moss landing commercial park mlcp for construction and material quality a plankton concentration time course can be conducted by inoculating the vessel interior with plankton so that a initial vessel concentration of 1 g l is achieved and measure for chlorophyll a chl a inside and outside the vessel not only for efficiency concerns but also for environmental concerns the semi permeable material can be selected to minimize the transport of biological mass to the surrounding environment the correct combination of materials and construction can be achieved when the baseline chl a levels in the seawater are maintained outside the vessel while maintaining close to the original 1 g l plankton concentration inside the vessel trace metals especially iron are the key to inducing plankton growth in ocean environments since the goal is to capture all biological growth induced by iron fertilization it may be desirable for organism exposure to the trace metals to occur only in the confines of the vessel in order to prevent the trace metals from diffusing outside the vessel an electromagnetic core designed to minimize trace metal dilution by ocean currents is.