Fishery Byproducts Can Become Fish Food

Pacific threadfin or "moi" (Rae Huo, Hawaii Department of Agriculture)

Research aided by the Agricultural Research Service (ARS), an agency of the U.S. Department of Agriculture, indicates that fishery byproducts can be converted into feeds for commercially farmed seafood. The work was done by the Oceanic Institute in Waimanalo, Hawaii, with help from food technologist Peter Bechtel of ARS’s unit in Kodiak, Alaska.

The scientists are currently examining how to best use fish byproducts to develop practical feeds that are nutritionally balanced, cost effective, and safe for the environment. They are taking fish parts that would normally be discarded — heads, tails, bones, skin, and internal organs — and converting them into feeds for shrimp and fish.

The team is testing the feeds on two Hawaiian seafood species: Pacific white shrimp (Litopenaeus vannamei) and Pacific threadfin (Polydactylus sexfilis, pictured left), known as “moi” in Hawaii. The research includes measurements of the nutrient composition of the feeds, evaluation of their ability to attract the shrimp and moi, estimation the food’s digestibility, and assessment the growth of the animals.

Other recent tests have shown that many fish parts from Alaska work well as feeding stimulants, which entice the shrimp to eat the plant-protein-based feed to which fish byproducts had been added.