Development of a Sustainable Polyculture Seaweeds and Fish on Molokai

Project Overview

Project Type: Research and Education
Funds awarded in 2001: $95,200.00
Projected End Date: 12/31/2004
Matching Non-Federal Funds: $18,743.93
Region: Western
State: Arizona
Principal Investigator:
Stephen Nelson
University of Arizona Environmental Research Lab

Annual Reports


  • Animals: fish


  • Animal Production: feed rations
  • Crop Production: nutrient cycling
  • Education and Training: demonstration, on-farm/ranch research
  • Production Systems: holistic management, integrated crop and livestock systems
  • Sustainable Communities: new business opportunities, sustainability measures


    A two-phase polyculture system was designed for producing seaweeds and marine fish on the island of Molokai. The system is operated by a nonprofit organization involved in aiding native Hawaiians. Research focused on developing protocols for the use of nutrients in effluent from fish culture to support the small-scale commercial production of the red alga Gracilaria parvispora, known locally as “ogo.” The fertilization protocols developed have been adopted by the grower, resulting in increased production and decreased labor. A series of workshops were held on Molokai to demonstrate the technology and provide training for local aquaculture workers.

    Project objectives:

    1. 1. Determine optimal stocking densities for fish and seaweeds in an integrated, tank-based production system for supplying fresh seafood to local markets.
      2. Determine nitrogen budgets for these systems for use in farm management to reduce reliance on artificial fertilizers, increase seaweed production, and prevent eutrophication of the local nearshore water.
      3. Increase farm revenues through product diversification and increased production.
      4. Encourage, through direct demonstration and the dissemination of technical information, the development of integrated aquaculture systems appropriate for small-scale coastal farms on Molokai and other Hawaiian islands
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.