SANTA CRUZ – UC Santa Cruz researchers Pallab Sarker and Anne Kapuscinski made a scientific breakthrough Thursday, changing the landscape of aquaculture and its future practice.
Aquaculture is a growing practice across the world, according to Kapuscinski. The number of fish eaten from fish farms is roughly even with the number of wild fish consumed, especially as the demand for fish has grown.
“Aquaculture continues to grow at a really rapid rate. Catches from fishing have essentially plateaued,” she said. “The only way to the gap between the demand and the plateau of fishing is through aquaculture.”
However, as with many other forms of farming, aquaculture comes with significant impacts to the environment. Current aquaculture practices are unsustainable. Conventional fish feed uses fish meal and fish oil that is made from small wild-caught fish like sardines.
Nearly 19-million tonnes of wild-caught fish are used to create fish feed and fish oil, Sarker said. Of that 19-million pounds, 70-82% is used in aquaculture. Analysts have projected the current rate of fish feed demand will surpass the forage-able fish population by 2037.
“This is a little bit alarming,” Sarker said. “It’s not socially sustainable. That’s why our research is really important. To reduce the reliance on wild-caught fish meal and fish oil.”
The way these small fish are used can be very harmful to the ecosystem across the world. Small fish like sardines usually feed ocean wildlife, Kapuscinski said. They are also vital to human populations in parts of the world that have fewer food options. These places rely on smaller wild fish for food security.
Other fish feeds use corn and soy as base ingredients. This has also been shown to be an unsustainable practice. The act of growing food, that could be consumed by people, to feed fish to be consumed by people is an unnecessary step in the process of food production.
Problems like these are why Sarker and Kapuscinski conducted research that developed more sustainable fish feed for fish farmers to use. Their formula is derived from two microalgae, nannochloropsis and schizochytrium. Both of these algae are high in protein and are what fish like tilapia feed on in the wild, Kapuscinski said.
The team’s research has shown significant results. Tests showed 58% faster growth in tilapia, Sarker said. The quality of the filet increased, as well, which is better for human consumption. Lastly, they were able to develop their feed at a lower cost than conventional fish feed.
“We’re really excited that we got a triple win from these results,” Kapuscinski said.
The research showed tremendous success. Since publishing the research, Sarker has been contacted by fish farms from around the world about the fish feed that is being produced at UCSC.
While this study was done on tilapia, Sarker and Kapuscinski hope to use their findings to continue research into developing fish feed for other types of commonly farmed fish.
“That could improve our lives,” Sarker said. “Local life. Local food security. It could expand. That’s really my intention. That’s why Ann and I and all of our team came here.”
Editor’s Note: The amount of fish used to make fish meal and oil is actually measured in tonnes, not pounds.
