Adventure in aquaponics

By | Charlotte Rutigliano

On a warm Friday afternoon, student volunteers help trim eight different varieties of basil leaves for a study headed by undergraduate Fisheries Biology major Bryan Lester.

Lester is studying which strain of basil grows the fastest using this aquaponics facility, he completed his second trial on Friday. The stains grown in the study are dark opal, holy, Italian large leaf, lemon, lime, spicy globe, sweet Genovese, and Thai.

A study he might not have been able to do without the help of Coast Seafoods, Hog Island Oyster Co., and Taylor Shellfish. According to assistant professor of Fisheries Biology Rafael Cuevas Uribe, past donations from Ameritas faculty ran out this past summer.

“The donation we received from these local businesses will help run the facility for about a year,” Cuevas Uribe said.

Since HSU starting leasing this facility, which belongs to the Humboldt Bay Harbor District, around two years ago Cuevas Uribe and the student volunteers have grown pak choi, lettuce, cilantro, chard, spinach, arugula, kale, and cabbage.

Cuevas Uribe started this program to help teach students about what aquaculture is and how to maintain and grow in a system like this.

“Aquaponics is an educational tool,” Cuevas Uribe said, “students often run their own research projects, like what Bryan is doing.”

According to Cuevas Uribe, aside from evaluating growth rates of plants, one of the other student-run research projects was evaluating the growth rates of the fish by changing their diets. A diet that normally consists of pellets made from fish meal, fish oils and other types of oils.

“This study evaluated the growth and feeding habits of the white sturgeon,” Cuevas Uribe said, “the students gave them a fish-free organic diet, and the results from that study were presented at a national conference.”

According to Cuevas Uribe, they get the white sturgeon from a fish farm in Galt, Ca.

“We have about 80 sturgeons that are 2-years old,” Cuevas Uribe said, “and another 400 sturgeons that are a few months old.”

Cuevas Uribe said that the fish are separated by their biometrics or their size, and student volunteers like senior Fisheries Biology major Alexis Harrison come down to the facility once a day to check on the water quality of the fish.

“We come down to check the oxygen levels, the temperature, the pH levels, ammonia levels, nitrite levels and nitrate levels,” Harrison said.

According to Cuevas Uribe, the fish help circulate the water for the plants. The water from the tanks the fish are held in is filtered by a polygeyser bead filter that holds bacterias that have nutrients the plants prefer.

“It’s a very symbiotic relationship,” Cuevas Uribe said, “even the waste drained from the filter, is strained and reused as soil for the plants.”

Cuevas Uribe said that everything that is grown at the facility is either taken home by the student volunteers or donated to the open community garden or the Food for People food bank in Eureka.

Lacy Ogan communications manager with Pacific Seafood, a company who has hired several HSU students as interns to work with the company because of this facility. Ogan said that companies are dedicated to the success of this program.

“They are in the process of helping to find a long-term funding source,” Ogan said, “so their resources can be focused on increasing internship programs.”