NEWS REVIEW Liposomes as nutrient delivery system under development
Fish fed live feeds without essential nutrient supplements (Control)
Fish fed live feeds enriched with microparticles containing essential nutrients
Researchers at Oregon State University are developing a new technology to deliver water-soluble nutrients to aquaculture-raised fish, oysters, clams and shrimp that will boost their growth rates and reduce the high rates of mortality that plague the industry.
into liposomes that we use to enrich the live feeds – for example, brine shrimp – or put inside of food pellets,” Langdon said. “The next step is to expand the project and look at how it affects different fish species, and whether we can make it cost-effective.”
As much as 80 percent of hatcheryreared larval marine fish die in their early life stages and researchers aren’t exactly sure why, according to Chris Langdon, a professor of fisheries at OSU’s Hatfield Marine Science Center and principal investigator on the project. One prevailing theory, he said, is that the critical watersoluble vitamins and amino acids rapidly leach from their tiny food pellets into the water.
Langdon and his colleagues have received a three-year, $630,000 grant from the National Sea Grant program to conduct further tests. The study is important, scientists say, because the United States has a major seafood deficit, importing more than $11 billion of seafood products annually from other countries.
“We’re having some success by packaging water-soluble nutrients
Aquaculture will be critical in the future to produce protein for the world’s growing population because many wild stocks of fish have already reached their peak
levels of sustainable harvest, Langdon noted. However, most marine fish hatcheries are not efficient models of production, he added. “If we can halve that mortality rate – and I think we can – it would be a game-changer,” Langdon said. The key to the preliminary success by the OSU scientists, which include post-doctoral researcher Matt Hawkyard, lies in production of liposomes, which are tiny vesicles, or bubbles, made out of the same material as a cell membrane. These liposomes are very efficient in containing nutrients – and other products – despite their small size. For example, the pellets used to feed larval aquatic animals are often smaller than a grain of sand,