Profile story: UH Hilo Professor of Aquaculture Armando García-Ortega on sustainable seafood production

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Professor García-Ortega’s groundbreaking 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)

By Susan Enright.

This post is an excerpt of Armando García-Ortega’s research profile on the website Keaohou that features UH Hilo faculty research and scholarly activity. 

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.

Read full profile at the UH Hilo research website Keaohou.

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

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