Sustainable Integrated Finfish/Nori Aquaculture for Bioremediation and Production of Food and Biochemicals: Culture and Mesocosm Studies

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Sustainable Aquaculture


Christopher Neefus UNH - Department of Biological Sciences Principal Investigator
Charles Yarish University of Connecticut - Stamford Co-Principal Investigator
George Kraemer State University of New York - Purchase Co-Principal Investigator
Thierry Chopin University of New Brunswick Co-Principal Investigator

Students Involved:

Jennifer Day UNH - Department of Biological Sciences
Jang Kim University of Connecticut - Stamford
Priya Sampath-Wiley UNH - Department of Biological Sciences
Troy Bray UNH - Department of Biological Sciences

It is important to note that nori aquaculture cannot solve the general problem of coastal eutrophication; the problem is too widespread and would require extensive and obtrusive nearshore growth facilities. However, the integration of Porphyra and finfish mariculture is one part of a comprehensive plan to reduce nutrient loads that would otherwise contribute to coastal eutrophication. The coupling of a nori production/bioremediation system to land-based effluent has three distinct advantages:

1) The effluent remains undiluted as it passes from the fishfarm to the seaweeds, maximizing seaweed uptake rates (Harrison and Druehl 1982, Wheeler 1988)

2) The costs and risks associated with the engineering structures needed to anchor bay-based (i.e., Asian) seaweed mariculture systems are avoided

3) Conflicts with recreational users of coastal waters are obviated


To obtain growth and nutrient uptake information for native species of the seaweed Porphyra that would allow successful integration with finfish aquaculture farms.


Growth rate, nutrient uptake and biochemical production of four native species of Porphyra will be determined over a range of light, temperature, nutrient and flow rate conditions. Initial studies will be done in laboratory culture. For the most promising strains and/or species, the assessment will continue in small and large-tank greenhouse mesocosms experiments. Some of the large-tank mesocosms studies will be integrated with the commercial summer flounder hatchery at Great Bay Aquafarms.


Finfish aquaculture is a rapidly growing industry both locally and globally. On a global scale, it is a multi-billion dollar industry. High levels of nutrients wasted in fish farm effluent represent an economic loss for the fish farm and a problem for the environment. Seaweed aquaculture is a multi-billion dollar industry in Asia. Annual production of seaweed Porphyra (nori) alone accounts for $US 1.8 billion.

Commercial aquaculture of Porphyra in the northeast is in its infancy. Seaweed requires significant amounts of nutrients to grow. Porphyra in particular can uptake very high levels of nutrients. We propose that integration of Porphyra production with land based finfish farms can be both economically and ecologically attractive. The project will provide the Porphyra culture information needed to make this work.

We were successful in determining the effects of irradiance, temperature, and nutrient concentration on production of biomass and the pigment phycoerythrin by Porphyra in short- (minutes) and longer-term (weeks) experiments conducted both in the controlled laboratory environment and semi-enclosed mesocosm (38 or 50 L) systems. We expanded the taxa investigated beyond four local species to include for comparison two Asian species, one of which (P. yezoensis) is the industry's main harvest. While all species are capable of rapid growth, P. amplissima recorded the highest sustained rates (24% d-1 averaged over one week). The long-term experiments were conducted with both laboratory-cultured (from seedstock) and field-collected tissue.
One problem we have identified, and for which a solution was not obtained (outside the scope of the project), was the inability to control the lifecycle of Porphyra (i.e., prevent vegetative tissue from producing archeospores). Controlling the induction of spore production is important because it is accompanied by loss of photosynthetic ability, reduced production, and tissue fragmentation as spores are liberated.
Porphyra species have rates of N and P uptake that are high enough to support the rapid growth we have measured. Irradiance and temperature are strong determinants of uptake rates (water motion was not investigated). We found evidence of saturation of growth (and, hence, nutrient uptake) at approximately 150 µM NH4, at least under low stocking densities (03-0.5 g FW L-1). This was, serendipitously, the concentration of the effluent of our industrial partner, Great Bay Aquafarms.
Our work has identified another aspect relevant to the development of a fully functional culture system. Porphyra removes nutrients during both lighted (day) and unlighted (night) conditions. However, production by P. amplissima and P. dioica is reduced by ca. 60% during dark periods (nutrient removal is awaiting sample processing). Since fish farmers will likely not use a system that requires an energy subsidy (light), this remains an unresolved issue.
The results of this project will help with the eventual development of seaweed culture systems and their integration into land-based aquaculture operations. This will aid in reducing the mass of inorganic nitrogen (N) and phosphorus (P) that are discharged into coastal waters, thereby decreasing the potential for the outbreak of blooms of unattractive and sometimes noxious algae. This benefit is of great importance for the Northeast because the coasts of Massachusetts, New York, Connecticut, and Rhode Island already suffer eutrophication to a greater or lesser extent.
Another benefit accrues to operators of finfish mariculture businesses: unassimilated N and P by fish are currently discharged in the effluent, representing a loss of money. By developing systems to capture N and P during the production of salable nori and biochemicals, operators will generate a product that compensates for expenses. Additionally, as legislative controls on the discharge of inorganic nutrients into coastal waters become more stringent, bioremediation via the production of nori will help finfish mariculture operators avoid non-compliance. Finally, results from this project will assist in the economic development and diversification by producing a new industry and class of jobs in the Northeast region.
Our project will benefit a broad spectrum of user groups. Obviously, operators of finfish mariculture businesses will benefit from the application of the results. As evidence of the industry's interest; GreatBay Aquaculture LLC (Newington, NH) contributed data, manpower, and space for the construction of the greenhouse and twin large-tank (12000-L each) recirculating system for the final phase of our study.


Available from the National Sea Grant Library (use NHU number to search) or NH Sea Grant

Journal Article

  • Kraemer, G., R. Carmona, C. Neefus, T. Chopin, S. Miller, X. Tang and C. Yarish (2004). Preliminary examination of the bioremediation and mariculture potential of a Northeast U.S.A. and an Asian species of "Porphyra." Bulletin Fish. Res. Agen. Supplement No. 1:77-82.
  • Carmona, R., G. Kraemer and C. Yarish. Exploring Northeast American and Asian species of Porphyra for use in an integrated finfish-algal aquaculture system. Aquaculture 252:54-65, 2006.
  • Neefus, C., A. Mathieson, A. Klein, B. Teasdale, T. Bray and C. Yarish (2002). "Porphyra birdiae sp. nov." (Bangiales, Rhodophyta): A new species from the northwest Atlantic. Algae 17(4):203-216.
  • Klein, A., A. Mathieson, C. Neefus, D. Cain, H. Taylor, B. Teasdale, A. West, E. Hehre, J. Brodie, C. Yarish and A. Wallace (2003). Identification of Northwestern Atlantic "Porphyra" (Bangiaceae, Bangiales) based on sequence variation in nuclear SSU and plastic rbcL genes. Phycologia 42(2):109-122.
  • Chopin, T., A. Buschmann, C. Halling, M. Troell, N. Kautsky, A. Neori, G. Kraemer, J. Zertuche-Gonzalez, C. Yarish and C. Neefus (2001). Integrating seaweeds into marine aquaculture systems: a key towards sustainability. Journal of Phycology 37(6):975-986.
  • Yarish, C., R. Wilkes, T. Chopin, X. Fei, A. Mathieson, A. Klein, C. Neefus, G. Mitman and I. Levine (1998). Domestication of indigenous "Porphyra" (nori) species for commercial cultivation in northeast America. World Aquaculture 29(4):26-31.
  • Chung, I., Y.Kang, C. Yarish, G. Kraemer and J. Lee (2002). Application of seaweed cultivation to the bioremediation of nutrient-rich effluent. Algae 17(3):187-194.
  • Kraemer, G., R. Carmona, T. Chopin, C. Neefus, X. Tang and C. Yarish (2005). Evaluation of the bioremediatory potential of several species of the red alga "Porphyra" using short-term measurements of nitrogen uptake as a rapid bioassay. Journal of Applied Phycology 16(6):489-497.
  • Troell, M., C. Halling, A. Neori, T. Chopin, A. Buschmann, N. Kautsky and C. Yarish (2003). Integrated mariculture: asking the right questions. Aquaculture 226:69-90.
  • Sahoo, D., X. Tang and C. Yarish (2002). "Porphyra"--the economic seaweed as a new experimental system. Current Science 83(11): 1313-1316.


  • Day, J. (2003). Effects of solar irradiance and ammonium on growth, nitrogen uptake and pigment content of "Porphyra umbilicalis" Kutzing, "P. linearis" Greville, "P. leucosticta" Thuret in LeJolis and "P. amplissima" Kjellman. Master's Thesis, University of New Hampshire.
  • Sampath-Wiley, P. (2003). Physiological ecology of the red alga "Porphyra" (Rhodophyta, Bangiales). Master's Thesis, University of New Hampshire.
  • Bray, T. (2003). A molecular and morphological survey of "Porphyra purpurea" (Roth) C. Agardh (Rhodophyta, Bangiales) in the northwest Atlantic. Master's Thesis, University of New Hampshire.

Book Chapter

  • Chopin, T., C. Yarish and G. Sharp (2007). Beyond the monospecific approach to animal aquaculture--the light of integrated multi-trophic aquaculture. Chapter 25 (pp. 447-458) in Ecological and Genetic Implications of Aquaculture Activities, Theresa Bert (ed.).


  • McVey, J., R. Stickney, C. Yarish and T. Chopin (2002). Aquatic polyculture and balanced ecosystem management: new paradigms for seafood production. In: Responsible Marine Aquaculture Symposium, R.R. Stickney and J.P. McVey, eds., pp. 91-104, Orlando, Fla., January 22-23, 2001.
  • Chopin, T., C. Yarish, C. Neefus, G. Kraemer, J. Zertuche-Gonzalez, E. Belyea and R. Carmona (2001). Aquaculture from a different angle: the seaweed perspective, and the rationale for promoting integrated aquaculture. In: Marine Aquaculture and the Environment: A Meeting for Stakeholders in the Northeast, proceedings of the Workshop, M.F. Tlusty, D.A. Bengston, H.O. Halvorson et al., eds., pp. 69-72, Boston, Mass., Jan. 11-13, 2001.
  • Chopin, T., C. Yarish, G. Sharp, C. Neefus, G. Kraemer, J. Zertuche-Gonzalez, E. Belyea, R. Carmona, G. Saunders and C. Bates (2001). Development of integrated aquaculture systems for responsible coastal zone management. In: Aquaculture and its Role in Integrated Coastal Zone Management, proceedings of the Eurpoean Aquaculture Society International Workshop, pp. 77-80, Oostende, Belgium, April 19-21, 2001.
  • Kraemer, G., R. Carmona, T. Chopin and C. Yarish (2000). Use of photosynthesis measurements in the choice of algal species for bioremediation. Fifth Biennial Long Island Sound Research Conference Proceedings 2000, pp. 113-117, Stamford, Conn., November 17-18, 2000.
  • Carmona, R., L. Chanes, G. Kraemer, T. Chopin, C. Neefus, J. Zertuche-Gonzalez, R. Cooper and C. Yarish (2000). Nitrogen uptake by "Porphyra purpurea": its role as a nutrient scrubber. Fifth Biennial Long Island Sound Research Conference Proceedings 2000, pp. 87-91, Stamford, Conn., Nov. 17-18, 2000.
  • Rawson Jr., M., C. Chen, R. Ji, M. Zhu, D. Wang, L. Wang, C. Yarish, J. Sullivan, T. Chopin and R. Carmona (2002). Understanding the interaction of extractive and fed aquaculture using ecosystem modelling. In: Responsible Marine Aquaculture Symposium, R.R. Stickney and J.P. McVey, eds., pp. 263-269, Orlando, Fla., January 22-23, 2001.