Preliminary examination of the bioremediation and mariculture potential of a Northeast U.S.A. and an Asian species of Porphyra

Finfish and shrimp mariculture operations produce nutrient-rich effluent that can threaten the health of coastal ecosystems if not properly managed. As part of an effort to develop an economically viable system of integrated polyculture, we have begun to evaluate the bioremediation and mariculture potential of Northeast U.S.A. and Asian species of Porphyra. We present here preliminary results based on short-and long-term experiments. Short-term nitrogen (N) uptake measurements were conducted over ca. 20 min in 50 mL tubes at 5-15 • Ž and at high (10 g FW L • | 1) stocking density. During long-term (28-d) experiments at 15 • Ž and at 0.4 g FW L • | 1 , we examined the growth, N assimilation into Porphyra tissue, and phycobiliprotein contents at three-to seven-day intervals as a function of N concentration (25, 75, 150, 300ƒÊ M). Performance (growth rate and bioremediation) was maximal at 150-300ƒÊ M inorganic N. Induction of archaeospore production reduced growth rates. Porphyra purpurea removed 96-100 • "of N within 3.5 days at 150ƒÊ M NH • { 4 . Overall, Porphyra appears to be an excellent choice for bioremediation of moderately eutrophic effluents, with the added benefit that tissue may be harvested for sale.