In the past 20 years, fish farm production worldwide has quadrupled. According to United Nations estimates, it’s on a pace to account for half of the world's total fish catch by 2030.
But most of the farm-produced seafood consumed in this country is imported, much of it from Asia, and that has raised concerns about environmental and public health regulation at overseas fish farms. Now some California aquaculture businesses are pitching environmentally friendly ways to bring more business here.
California has some of the strictest environmental protection laws for fish farming in the country. But so far, the state’s aquaculture industry is embryonic. It added up to just $175 million in total value last year, said Randy Lovell, the state Department of Fish and Wildlife aquaculture coordinator.
Catalina Sea Ranch spent more than two years convincing the California Coastal Commission that it can operate in a stretch of ocean about 6 miles offshore from Long Beach without hurting the environment.
Company president Phil Cruver says he’s ready to make good on his promises. At a recent press event, he displayed an array of buoy-mounted monitors that will transmit data from the farm site in real time, using an ocean-going cellular phone network.
“There’s nothing that we’ll be putting in to the ocean that’s not already there,” he said. “We’re going to show on 100 acres, independent institutions, that offshore aquaculture is not detrimental to the environmental health of the oceans.”
Data from the Sea Ranch monitors will be freely available to researchers, and regulators will track it to determine if operations there have caused environmental harm, Cruver said.
He said he’s well on the way to the $5 million he needs to fund the project, which will be located on the San Pedro shelf. There, cold, nutrient-rich water rises from the depths further out. In October, Cruver plans to set out 40 heavy ropes packed with baby mussels, suspended from buoys and anchored to the sea floor. Next June, he expects to harvest his first crop.
One of the big concerns about fish farming is that farm stock might gobble food that the wild population needs or foul the water with waste. Cruver say his university research partners will monitor the waters around the Sea Ranch and he’ll take their direction to keep the ecosystem safe.
For the company’s shore-based breeding tanks, Cruver hopes to grow his own food.
He’ll use technology developed by Los Angeles-based OriginOil. The company’s research director, Nick Eckelberry, brought an aquarium-sized tank of murky green water to the Sea Ranch press event.
To show how his system works, Eckelberry flipped a switch.
Soon, a ghostly cloud of tiny bubbles rose to the surface. The bubbles were oxygen and hydrogen gas, the remnants of water molecules broken up by the electric charge and carrying particles of algae with them as they surfaced. An automated comb swept the water, collecting a pea-soup paste.
Eckelberry says that paste makes good feed for baby mussels and other farmed seafood, too. Right now, fish farms rely on feed made from ground-up anchovies, sardines and mackerel, and that can deplete ocean ecosystems. Eckelberry says algae-based food is a good alternative, but making it has required energy-hungry centrifuges. Until now. He says his process makes algae-based food affordable.
“The problem is that you typically have a lot of water and a little bit of algae, and the question is, ‘How do you get the algae out affordably?’ Eckelberry said. “Almost serendipitously, that is what this system does.”
Eckelberry said another alternate food based on soy costs more than times what he’ll have to charge for his algae-based fish chow.
Lovell, the state aquaculture coordinator, said the National Oceanic and Atmospheric Administration has conducted broad research in alternative feeds in recent years.
Typically, fish farms have an additional problem: how to dispose of toxic bio waste. Twenty miles north of the Sea Ranch headquarters, another entrepreneur is working on a solution.
David Rosenstein slides open a greenhouse door. There are lush plantings of bok choy, red Russian kale, basil, Bavarian lettuce, celery and more, all growing in water, like a conventional hydroponics operation.
But in a corner, there are two large tanks full of water. Rosenstein reaches into one with a net.
“I know. Hold on, guys,” he murmurs into the tank. There’s a little splash, then a flurry, with water flying in all directions.
“Hold on! One second, please!” Rosenstein pleads, but the struggle just gets fiercer.
Finally, dripping with water and panting slightly, Rosenstein holds up a 5-pound catfish in the net for a second. It thrashes free and plunges back into the depths.
Rosenstein’s greenhouse uses aquaponics, which blends hydroponics and fish farming.
Another farmer would have to worry about disposing of fecal material. Not Rosenstein, he says.
“All his waste streams, which he currently pays top dollar to become EPA-compliant, is something I do naturally within the system,” Rosenstein said. “His dollar stops at the point where he harvests his fish. But mine continues. Because I’m doing this system, it’s not a cost. It’s part of the design of the system.”
He composts the waste, turning it into fertilizer for his plants, which in turn helps to purify the water for the fish.
Lovell said he’s intrigued by such models.
“There’s a lot of attraction to it because of the closing of the cycle, the sharing of nutrients between fish and plants. It pushes a lot of buttons that make a lot of sense, myself included,” he said. “However, many of the people who are involved in aquaponics are making a fair amount of their money by training other people to do it. There aren’t very many commercial-scale aquaponics companies that are making their money on the production itself.”
Still, California Department of Food and Agriculture Secretary Karen Ross said she sees a lot of promise in the approach
“If you look at these systems, a lot of them are recycling water, which is really one of the keys, is, ‘How do we use every drop of precious water to maximize the value that comes out of that?’”
Ross said a growing sense of urgency over the depletion of wild fish stocks, coupled with the current drought, has state and federal agencies studying environmentally friendly aquaculture. And she knows of several investors who are preparing to launch more such projects.
Get the best of KQED's science coverage in your inbox weekly.