Just beyond and to the right of the agriculture building, Hale Uluwehi, lie five large round blue plastic tanks. Nearing these tanks — 8 feet in diameter by 3 feet high — you’ll hear a gurgling sound. Upon closer inspection, you’ll see fish swirling and splashing around in a pool of bubbling water.
These fish tanks are part of the AQUA 106 (Small Scale Aquaculture) and AQUA 201 (The Hawaii Fishpond) science classes here at WCC. Students are learning to raise tilapia —Oreochromis urolepis honorarium — in a controlled environment.
One might ask, “Why?”
“I look at these five tanks as the sustainability I can provide my future family,” explains Jessica Spencer, WCC Hawaiian Fishponds 201 student. “Every day when I feed the fish, I learn about them, the water and surroundings and how to feed my family nutritious meals and decrease my grocery bill.”
Fish depletion has been an ongoing concern worldwide. According to one British Broadcasting Corporation report, “Global fish stocks are exploited or depleted to such a degree that our generation may be the last to catch food from the oceans.”
Faced with that kind of alarming information, aquaculturists have modified an old Chinese proverb to reflect todayʻs situation: “Give a fish to someone, feed them for the day; teach them to raise fish and you feed them and their families for a lifetime.” Fish remains a major source of protein in many cultures.
“Learn to farm fish and feed your families” is a concept WCC teacher Leonard Young is helping his classes to understand.
The tilapia are housed in different tanks according to their size — from tiny fish fry (babies) up to eight inches.
Connected to the first tank is an elevated rectangular wooden grow bed about the size of a ping-pong table with 12-inch sides.
In the growbed flourishes leafy green ong choy (swamp spinach) basking in the sun and swaying in the gentle breeze. Students recognize that the ong choy are thriving in their environment.
Young has combined aquaculture (fish farming in a controlled environment) with hydroponics (growing plants in a water substrate), which is known today as aquaponics. The common factor is the water used by both these systems.
The waste (ammonia) from the fish tanks is converted to nitrates (biogeochemical nitrogen cycle), which are nutrients for the plants.
The plants absorb the nutrients and the water is returned, cleaned and oxygenated, to the fish in the tanks.
Aquaponics is a sustainable circulatory grow system that is environmentally friendly.
Those five round blue fish tanks all in a row represent a “hands-on approach” to raising fish along with growing plants.
“It’s a process,” Young says, explaining there are different ways to achieve the desired outcome. Experimenting with fish farming gives students a better feel for the process.
Gavin Hirazumi, a student of Young’s, explains, “Taking care of the fish tanks is a rare opportunity that comes with great rewards. It’s physical and direct activity that can still engage the young, even as we head further into the digital age.”
Young plans on constructing grow beds for each of the four remaining fish tanks to grow other types of vegetables.
All in all, the fish tank project is a lesson in self-sustainability and hope for the future, he says.
by Wayne Ricks, Ka ‘Ohana Staff Reporter