Minnesota university’s yellow perch RAS project aims to help local fish farmers

For several years now, Minnesota fish farmers have been in search of a fish species that was a higher market value than tilapia. Yellow perch, with its mild, sweet flavour with firm, flaky white flesh, appears to be the answer. Unfortunately, the supply of yellow perch fingerlings for aquaculture is limited.

An ongoing recirculating aquaculture system (RAS) project at the University of Minnesota might soon have the answer for them. Moving production of the yellow perch from outdoors to indoors could increase growth and production rates and provide and “expand the season when fresh yellow perch fillets would be available to consumers,” according to Amy Schrank, MNSG fisheries and aquaculture extension educator and project lead.

The Minnesota Sea Grant’s Egg-to-Market Yellow Perch Project, which kicked off some two years was designed to create a detailed how-to manual for small to medium-scale yellow perch producers.

Yellow perch project team will grow two batches of fish from embryo to harvest size. The team will compare fish growth in two separate systems: RAS and flow through system.

The yellow perch embryos by the researchers hatched into thousands of skinny little larvae around one-fourth of an inch in length. While the larvae grew into juvenile fish, the project team plumbed the flow-through and constructed the recirculating aquaculture systems.

The RAS tanks only require around 33 gallons of new water per day. The flow-through system tanks use more than 15,000 gallons of water per day. For a quick look at how the team put together the systems you can check out this link.

Recently, the team transferred 1,752 fish into four, 250-gallon circular tanks (438 per tank) that now form the project’s RAS and flow-through systems so they could continue to grow.

“The amount of feed is increased as the fish grow and every 30 days our team weighs and measures around 10 per cent of the fish in each tank to track their progress,” according to the MNSG aquaculture extension associate Kieran Smith. “Just 12 months after they hatch into larvae, the adult fish will be ready for harvest, processing, and eating! Fish tacos anyone?”