One of our professors, Dick Lee, had some interesting visitors yesterday. They were international businessmen who are looking to get into the aquaculture (fish farming) business in one way or another. They were interested in learning more about Dick’s black sea bass project.

Dick is one of our “emeritus professors” who has officially retired, but still comes in and puts in a good day’s work. One of his pet projects is developing a commercially viable system for raising black sea bass for the sushi market.

Black sea bass is a relatively small (2 lbs at market size) salt water fish that is apparently in fair demand by sushi chefs. The goal of the project is to develop a system and work out the bugs to raise the fish in a commercially viable and environmentally friendly manner. A big issue with many aquaculture projects is their effect on the environment. Typically, in most aquaculture systems some clean water comes into the system, and some waste water is returned to the environment. Dick and his assistant, Karrie Brinkley, have been operating a closed-cycle system that has no discharge into the environment.

They actually operate two separate systems or cycles. On one side is the black sea bass raised in salt water tanks. On the other side is tilapia in fresh water tanks and ponds.

Dick and Karrie use the young tilapia “fry” as the primary food for the black sea bass. This serves two ends. It is an excellent, high-protein diet for the black sea bass. They have been growing to market weight in 11 months, significantly shorter than the typical two years.

Also, in a typical fish farm situation, the fish are fed food pellets. (Think of dry dog food.) Many of those are not eaten. They sink to the bottom or float to the top and generally gunk up the water. In the system here, the baby tilapia just swim around until some hungry sea bass sucks them down in one gulp. No muss. No fuss. And much cleaner water.

On both the salt water and fresh water side of the system, they use algae and bacteria to cleanse the natural fish waste from the water. The water is pumped into a series of trays full of algae mats and bacteria. It takes roughly 45 minutes for it to flow downhill from one tray to the next until the water at the bottom is relatively clean and is pumped back into the tanks.

On the fresh water side of the project is one more cool twist. It turns out what is waste for fish water is great fertilizer for plants. Dick and Karrie grow hydroponic vegetables in the fresh water trays. It serves a double purpose. The vegetables help pull those waste/nutrients out of the water and can also serve as a second stream of revenue for some would-be fish farmer. Just yesterday, Karrie put her latest crop of cucumbers out in the lunch room for her friends and co-workers. Good stuff.

Dick approached me earlier this week about setting up a taste test. He has been raising some black sea bass on the traditional food pellet diet. He would like to find some knowledgeable sushi fans and offer them some delicacies from black sea bass raised on both the food pellet and the tilapia diets. They can tell him if they taste different and which one tastes better.

We’ll let you know how the “Sushi Challenge” turns out.