Dr. James Rakocy
My personal journey here is a long one starting with a passion for fishing, ornamental fish breeding and gardening as a child growing up in Wisconsin in the 1950s. After graduating from the University of Wisconsin with a B.S. degree in zoology in 1967, I went to Sierra Leone, West Africa as a Peace Corps Volunteer. I taught biology and chemistry at a secondary school and organized a school garden program where I quickly discovered that tropical soils contained little organic matter and nutrients and could not produce the abundant harvests of rich Wisconsin soils. I witnessed considerable malnutrition, which instilled an interest in food production.
While working on my M.S. degree in environmental biology from the University of North Carolina, which I obtained in 1973, I studied the effect of carp culture on tertiary sewage treatment. I subsequently worked on water quality projects for the Wisconsin Department of Natural Resources and environmental consulting firms in Wisconsin and Massachusetts.
Upon entering Auburn University for my PhD degree, all my previous interests gelled. I constructed and evaluated an aquaponic system that produced tilapia, ornamental fish, aquatic plants and edible plants such as watercress and water chestnuts. In addition to my course work in aquaculture I took several civil engineering courses in wastewater treatment. I graduated in 1980 with a PhD degree in aquaculture.
In 1980 I began 30 years of employment at the University of the Virgin Islands (UVI) where my main mission was to develop aquaponic technology. I became Research Professor of Aquaculture and Director of the Agricultural Experiment Station. I served as Aquaculture Program Leader and directed research on the culture of tilapia in aquaponic systems. The emphasis of my research was on the conservation and reuse of water and nutrient recycling. I also directed research on biofloc systems where settling and filtration systems were employed to recover and dewater solid waste to be used as an organic fertilizer for field crops.
At UVI my focus switched to garden plants such as vegetables and herbs. My research team first built a model aquaponic system out of three and one half oil barrels, a production method that has recently become popular. It produced 100 lbs (45 kg) of food in 4.5 months. We next built six replicated systems for controlled experiments. Each system contained two hydroponic tanks with a total growing area of 154 ft2 (14.3 m2), and a 3,000-gal (11.4 m3) fish tank. After conducting many experiments in these systems, we scaled up by constructing another system containing two hydroponic tanks with total growing area of 768 ft2 (71.4 m2) and a 3,000-gal (11.4 m3) fish tank. After several production trials, we built the first commercial-scale UVI system containing six hydroponic tanks with a total growing area of 2303 ft2 (214 m2) and four fish rearing tanks, each with a water volume of 1,320 gal (5.0 m3). The objective was to stagger fish production among several tanks to keep feed input to the system and therefore nutrient generation relatively constant. After several long-term trials, one lasting 3 years, we installed larger fish tanks containing 2,060 gal (7.8 m3) of water. Numerous modifications were made to this system before arriving at the current commercial-scale UVI aquaponic system.
During the development process we initially worked with media beds before switching to raft culture. We modified the effluent treatment process, eventually employing clarification, filtration and degassing. We evaluated production techniques for Nile tilapia, red tilapia and more than 30 types of vegetable, herbs and flowers. By 1999, the UVI system had proven to be reliable, robust and productive. We therefore launched a training program and taught 566 students from 45 U.S states and territories and 56 other counties. Today numerous hobby-level, educational and commercial-scale aquaponic systems utilize UVI aquaponic technology. Several aquaponic courses have spun off from the UVI course and are taught by former students.
As the UVI aquaponic system became widely known, a UVI colleague and I were invited to construct aquaponic systems based on the UVI design at the Rutgers University EcoComplex in New Jersey and at the Crop Diversification Center South in Alberta, Canada. The UVI aquaponic systems at these locations were used for research, teaching and extension. The systems performed well in environmentally controlled greenhouses in temperate climates.
While at UVI I authored or co-authored 96 papers (book chapters, journal articles, publications in conference proceedings, technical reports, fact sheets and popular articles), co-edited Volumes 1 and 2 of Tilapia Aquaculture in the Americas (522 pages) for the World Aquaculture Society and wrote Aquaponics Q&A (235 pages). Dr. Wilson Lennard and I are currently writing Aquaponics: a Comprehensive Guide to Proven Principles and Practices.
I have given 114 presentations at conferences and workshops in the U.S. and overseas. I have been invited to speak on aquaponics in Mexico, Colombia, Canada, Portugal, Norway, Japan, Vietnam, Malaysia, Singapore, Australia and Saudi Arabia. I have also given aquaponic presentations in Trinidad, Brazil, China and Thailand.
I initiated and co-taught the UVI International Tilapia Aquaculture and Aquaponics Course 14 times. I co-taught aquaponic short courses for the University of Arizona (Tucson), the University of the West Indies (Trinidad), the University of Hawaii (Hilo), Nelson and Pade (Wisconsin), Aquatic Eco-Systems (Florida) and a business in Australia (Brisbane).
I served on the Board of Directors of the American Tilapia Association and the Southern Regional Aquaculture Center. I was honored for my achievements in aquaponics at the Second International Aquaponics Congress in Cancun, Mexico in 2011.
In my final years at UVI before retiring I was inundated with e-mails asking questions about aquaponics. Since retiring in 2010 the flow of e-mails has not slowed. I have therefore partnered with Dr. Wilson Lennard, a leading aquaponics researcher and consultant, to write an book on aquaponics, which will hopefully answer all your questions, and to make ourselves available for consulting.
Dr. Wilson Lennard
My interest began with childhood aquarium fish keeping and breeding. I worked in the aquarium fish industry for 2 years and managed an aquarium fish importation and quarantine facility.
In 1990 I completed a B.Sc. degree in Applied Biology at Royal Melbourne Institute of Technology University (RMITU), with a major in ecology and biochemistry. In 1992 I completed a B.Sc. Honors degree in applied biology, majoring in freshwater crayfish (yabby) reproductive biology and breeding for the aquaculture industry where I developed a method to artificially incubate yabby eggs, a method to electro-stimulate yabby males for spermatophore release and methods to determine the reproductive condition of female yabbys.
I spent the next 6 years developing a career as a freshwater biologist, working for many and varied universities and government organizations, performing research and field work. It was here that I experienced the impacts to freshwater environments of mainstream agricultural practices.
In mid 2000 I started to do a literature search on aquaponics and found very little information apart from the extensive work of Dr. James Rakocy and his UVI team. I put together a 100 page research proposal and was offered a PhD scholarship by the Australian Federal Governments RIRDC (Rural Industry Research and Development Corporation); one of three scholarships offered that year. I spent 3 years in the laboratory at RMITU performing a number of replicated experiments to optimize aquaponics. I tested many different aquaponic parameters in my 12 system, media-bed setup, produced a mathematical model for nutrient balancing in the system and ran a 16 week lettuce production trial to test my results. I was conferred the degree of Doctorate of Philosophy (Applied Biology) in August 2006.
In 2005 I designed and built my first commercial aquaponic system in Australia and ran it, in partnership, as a business. I achieved success growing and selling Murray Cod to local restaurants and herbs to a local pesto and dips manufacturer. I developed a “direct sales to the restaurant door” approach and serviced many restaurants in the region.
In 2008 I joined a Melbourne-based hydraulic engineering firm to work in the water-sensitive urban design and constructed wetland industries. It was here that I learned about sizing and designing media-based constructed treatment wetlands, hydraulic engineering, sizing and designing small-scale decentralized sewage treatment plants, sizing and designing grey water treatment systems and Computer Aided Design (CAD) drawing and design techniques.
In 2009 I traveled to New Zealand, designing, constructing, commissioning and testing an NFT aquaponic system. Two years of trials were performed to compare aquaponic plant production with standard hydroponic plant production, including herb comparison trials, lettuce comparison trials and a 5-month commercial lettuce run. This was a very successful project which proved that aquaponics could stand side by side with standard hydroponics in terms of plant production and plant quality.
I have since consulted on several commercial-scale aquaponic projects and have taught a number of aquaponic workshops (both hobby-scale and commercial) and consulted to foreign and Australian governments on aquaponics. I developed a free hobby aquaponic system design tool (recently updated to Version 2.0), and I have recently released a number of free aquaponic fact sheets for the wider aquaponics community. The latest project I am working on is a New Zealand Aid Program to introduce aquaponics into the Pacific Islands for food security and business development.
I have written and published several scientific publications, spoken on aquaponics at scientific conferences in Australia, Vietnam and Mexico, published in the associated conference proceedings and taught aquaponic short courses in Australia and the United States (Hawaii and Florida). I have written numerous articles about aquaponics for trade journals and magazines and have lectured on several subjects at Australian universities (Aquaculture, Statistics, Environmental Science Architecture, Aquatic Ecology and Ecology). I have also been a guest lecturer at the UVI International Tilapia Aquaculture and Aquaponics Course for 3 years and have now developed a teaching association with Dr. James Rakocy and Pentair Aquatic Eco-Systems (the world’s largest aquaculture equipment supplier) where we teach commercial aquaponic workshops in the U.S. two times a year.
In addition to my aquaponic experience, I have scientific and engineering skills and experience in associated aquatic disciplines, including freshwater aquaculture, marine aquaculture, hydroponics, integrated aquatic farming systems, freshwater aquatic ecology and environmental biology. I also have skills in building and construction, plumbing, electrical wiring, sheet metal fabrication and wood working. These skills have been accumulated over a professional career of almost 20 years. I therefore bring a wide array of experience and a holistic environmental approach to the field of aquaponics. Dr. James Rakocy and I have now teamed up to consult and write an aquaponics book so we can share our accumulated wealth of aquaponic information.