Armando García-Ortega, Professor of Aquaculture

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Professor García-Ortega’s research shows that vegetarian diets can be fed not only to carnivorous fish, but to all commercially farmed fish.

A photo of Armando García-Ortega with background of kahala fingerlings.
Professor of Aquaculture Armando García-Ortega. In the background are kahala fingerlings the professor and his students study at UH Hilo aquaculture facilities. (Courtesy photos)

Posted July 16, 2024

Professor with long-handled net scoops up large dark fish.
Professor of Aquaculture García-Ortega catches kahala in a broodstock fish tank at the UH Hilo Pacific Aquaculture and Coastal Resources Center in Keaukaha, Hilo, where he has conducted studies. The fish is Seriola rivoliana or kahala, also called kanpachi. The species is native to Hawaiʻi — although it’s also found in many other parts in the world — and is produced commercially in open ocean net pens off Keahole Point in Kona. (Courtesy photo)

Armando García-Ortega is a professor of aquaculture at the University of Hawaiʻi at Hilo. His area of expertise is in aquaculture and sustainable seafood production. Specifically, he researches the development of innovative aqua-feed formulations free of fish meal and fish oil using algae, yeast, insect meals, and optimizing farming technology of tropical marine species in land-based aquaculture systems.

García-Ortega received his master of science in aquaculture from Ghent University, Belgium, in 1993, and his doctor of philosophy in aquaculture from Wageningen University, The Netherlands, in 1999. He arrived at UH Hilo in 2011 and received tenure in 2016. 

The aquaculturist is author or co-author of 24 peer-reviewed articles, 22 of which are in indexed journals, three industry books or manuals, six book chapters, 14 conference proceedings and 46 conference abstracts. Of that work, he sites one of his first-authored papers as the most important to the academic literature of his field.

The paper, “Evaluation of fish meal and fish oil replacement by soybean protein and algal meal from Schizochytrium limacinum in diets for giant grouper Epinephelus lanceolatus,” is one of the most cited articles published in 2016 in the journal Aquaculture, considered as “extremely highly cited” with 20 times more citations than average in the field.

Sustainable seafood production: First successful study on combined use of algal meals for carnivorous fish

In the groundbreaking fish meal study, García-Ortega and his research team conclude that diets for giant grouper containing 40 percent soy and algal ingredients yield similar growth as diets based on fish ingredients, and that Schizochytrium limacinum meal can be used as the main lipid source in diets for giant grouper.

The research demonstrates that in farmed fish, algal meals can successfully replace traditional feed ingredients derived from reduction fisheries. It is the first successful study on combined use of algae meals (Arthrospira, Schizochytrium) to completely replace fish meal, fish oil, soybean meal in feeds for fish (tilapia, striped mullet), and the first use of DHA-rich Schizochytrium meal in farmed marine fish (longfin yellowtail, grouper).

“We reported for the first time carnivorous marine fish can be farmed with feeds containing algal meals and produce the same fish growth and nutritional quality as the unsustainable practice of feeding fish with other fish,” says García-Ortega. “We basically propose to feed vegetarian diets not only to carnivorous fish, but to all farmed fish.”

Fourteen bowls of powders, granules, and liquids.
Feed ingredients used in Professor García-Ortega’s research. (Courtesy photo)

García-Ortega also proposes using, as much as possible, locally produced feedstuffs to reduce the carbon footprint from aquaculture.

“In Hawaiʻi and the Pacific Islands, transporting feed or feed ingredients for fish farming increases the environmental costs of our food production,” explains García-Ortega. “By-products from the locally produced algae Spirulina and Haeamatococcus can be used to replace at least half of the ingredients in fish feeds. If planned adequately, seafood production by aquaculture can contribute to increasing food security in the islands.”

García-Ortega is collaborating with the local aquaculture industry to develop fish feeds using locally produced limu (seaweeds) as part of the fish feed ingredients. “The aim is to increase the number of available feedstuffs to increase the potential for local production of animal feeds,” he says.

Students are the foundation

Professor García-Ortega says students are the foundation of the research he conducts at UH Hilo.

“They perform the fundamentals of fish care and their cultivation by aquaculture,” says the professor. “They actively participate by assisting in the manufacture of fish feeds, monitoring water quality during fish feeding trials, feeding the fish and maintain the life support systems in the aquaculture facilities at the UH Hilo Panaʻewa farm.”

Large class of students with professor in outdoor setting.
Professor García-Ortega with an Introduction to Aquaculture (AQUA 262) class at the UH Hilo Agricultural Farm Laboratory in Panaʻewa. (Courtesy photo)
Fish fillets are seared with a blow torch and packed into take out boxes with salad.
Kahala (kanpachi) fillets farmed by UH Hilo students are served at an alumni and community reception at the UH Hilo Agricultural Farm Laboratory in Panaʻewa. (Courtesy photo)

Students also learn the basics of how to design and perform scientific studies.

“Thanks to our cooperation with the industry, students carry out internships with the aquaculture companies at NELHA [Natural Energy Laboratory of Hawaii Authority] in Kailua-Kona, where they can further their learning in commercial farm settings,” García-Ortega says. “These companies are often the first place students find jobs after graduation.”

Nine students and the professor gather for photo. Industrial machinery and warehouses in background.
Professor García-Ortega with his students on field trip to commercial abalone aquaculture farm in Kona. (Courtesy photo)

García-Ortegaʻs research continues with testing alternative ingredients from algae, limu, insect and bacterial origin in innovative feed formulations for sustainable seafood production. He says his future goals are to increase stakeholders’ awareness of local food production by aquaculture and the advantages of production of marine fish and limu in land-based farms.

Learn more about Professor García-Ortega on LinkedIn.

By Susan Enright, a public information specialist for the Office of the Chancellor and editor of Keaohou and UH Hilo Stories. She received her bachelor of arts in English and certificate in women’s studies from UH Hilo.