Researchers at UC Santa Cruz’s Ecological Aquaculture Laboratory won a three-year, million dollar grant from the National Food Institute’s Agriculture and Food Research Initiative and USDA Agriculture. This funding will support collaborative research to develop, test and evaluate new low-polluting fish feed formulas for farmed rainbow trout.
Associate Research Professor of Environmental Studies Pallab Sarker will lead this work alongside Professor of Environmental Studies Anne Kapuscinski and Luke Gardner, a California Sea Grant extension specialist affiliated with UC San Diego. The team will use a marine microalgae as an ingredient in their fish feed, and the resulting experimental formulas will be field tested at operating trout farms in California.
The goal is to create a new ecologically sustainable and economically viable feeding option that maximizes fish growth while limiting the potential for water pollution during the fish farming process.
Water pollution is a sustainability challenge for the aquaculture industry, as fish waste contains nitrogen and phosphorus. These are nutrients that have the potential to fuel algal blooms in nearby waterways, if wastewater from large-scale fish production is not treated properly. But the low polluting fish feed is specially formulated to help meet this challenge.
Low-polluting varieties of fish feed contain as little nitrogen and phosphorus as possible and provide these nutrients in a form that is easily digested and absorbed by the fish, to minimize the amount that the fish will subsequently excrete in the fish. their waste. These foods are a prime example of how scientific innovation has helped increase the sustainability of aquaculture.
“The overhaul of the composition of aquaculture feed has been a key lever in the fight against nutrient pollution“Sarker explained. “Low-polluting aquaculture feed helps conserve natural ecosystems and provide clean water. “
The UC Santa Cruz team hope their work will help increase the variety and quality of low-polluting feeding options available to fish farmers.
Sarker and Kapuscinski have worked for years to develop new sustainable fish food formulas by recycling biomass leftovers from the commercial production of marine microalgae species, which are used to make omega-3 dietary supplements for humans. Most teams priority work was geared towards the combination of different marine microalgae to replace the traditional ingredients of fishmeal and fish oil from wild fish. But the team also wants their food formulas to help reduce water pollution. The new grant will therefore help them to test this aspect.
First, the researchers will experiment with different methods of processing microalgae ingredients to make them as digestible as possible for rainbow trout. Then, they will determine the ideal amount of microalgae that can replace the fish-based ingredients. Then, they will develop low-polluting diets and determine both their effects on the growth of trout and their potential to reduce water pollution from the resulting trout waste.
These first steps will take place in the aquaculture research laboratory on the UCSC farm, but through the partnership with California Sea Grant, the team will also have the opportunity to assess the performance of the feed in the real world through trials in fish farms. Anne Kapuscinski and Luke Gardner will co-lead this collaboration with a small group of trout farms in California. They will also recruit other leaders from across the aquaculture industry to learn more about low-pollution diets and generate business interest.
“We are delighted that this grant allows us to test our new diets on commercial trout farms,” said Kapuscinski. “The proof is in the pudding – or in this case, in fish farming – so I think this will go a long way in convincing more farmers and aquaculture feed manufacturers to adopt low-emission diets.”
Project research collaborators will also model the economic feasibility of the novel food on a large scale. And a life cycle assessment will compare the overall environmental impact of the new formula with conventional foods – from the initial production of food ingredients to the final fish fillet – across a wide range of impact categories, including including greenhouse gas and eutrophication emissions, water consumption and the use of biotic resources.
Sarker and Kapuscinski experimented with recycled marine microalgae biomass as an alternative food ingredient in part because they believe it has the potential to be more sustainable than conventional food ingredients, such as fish meal and oil or fish oil. land crops, such as corn, wheat or soybeans. Assessing the life cycle of their diet will provide valuable new information on this issue.
Ultimately, as aquaculture expands to meet global protein needs, the team hopes that further research will ensure that the sustainability of the industry continues to grow along with it.
“Aquaculture has gained a bad reputation with American consumers, which is slowing the progress of aquaculture, especially for species like farmed salmon or farmed trout where their required diet has a greater environmental impact. high, ”Sarker said. “But that impact will likely continue to be reduced through research and innovations that find better ways to feed fish and help encourage the best and most responsible practices in aquaculture.”