Desert Fishing: Helping to Build a Negev Industry
Desert Fishing: Helping to Build a Negev Industry
September 28, 2012
When the idea of fish farming in the desert came up about 25 years ago, it sounded like a joke, recalls Prof. Samuel Appelbaum, who heads the Bengis Center for Desert Aquaculture at the Jacob Blaustein Institutes for Desert Research (BIDR). “We were the first to realize that the brackish water beneath the desert could be used for agriculture, aquaculture and a combination of the two,” he recounts.
During the past few decades, Appelbaum and his BGU colleagues have pioneered the farming of fish, shrimp and crustaceans in the Negev alongside horticulture specialists developing agricultural crops. The results draw increasing attention from the rest of the world as more drylands materialize and the threat of world hunger rises. Similar farming techniques are now used in arid lands as far flung as Arizona, India and Australia.
In the Negev, the process builds on the fact that 50 to 100 feet below the desert surface lies ancient water with a temperature of 104 degrees Fahrenheit and a slight salinity, less Than 10 percent the salt of seawater. “It percolated down thousands of years ago when it was more rainy than now,” Appelbaum explains. The less rain the region experiences, the more treasured this once-hidden reservoir becomes.
With some trial and error over the years it was proved that this naturally warm water, pumped into closed systems, provides an excellent environment for certain fish and other water dwellers, including sea bass, tilapia, bream, barramundi, catfish, guppies, clown fish and more.
The fish excrete metabolites, highly nutritious to plants, into the water, which once adjusted to specific needs, can be re-circulated to grow agricultural products. Continuing the cycle, the plants absorb the metabolites through their roots and clean up the water, which is then recycled back into the fish ponds or pools.
“This water is much cheaper than fresh water in Israel and it’s available throughout the year independent of weather conditions,” Appelbaum observes. “It’s free of pollutants— there was no industry when it hit the ground––and we don’t have to pay to warm it.” The subsurface water is not, however, a renewable source: used carefully, it will last for perhaps 50 years, Appelbaum estimates, by which time he believes desalination techniques will solve the water challenge.
Academia Goes Fishing
The Negev fish farms were developed through close collaboration between BGU scientists and local entrepreneurs, and University researchers continue to Serve as consultants and troubleshooters to the local industry. Over time, some farms that raise fish for the dinner table have given way to the growing of ornamental fish for the aquarium, and new fish farms growing tropical species have been established.
Farmers have found it difficult to compete with other parts of the world growing edible fish and even other parts of Israel, where production costs are cheaper.
“The infrastructure costs for ornamental fish don’t have to be so high,” explains Dr. Dina Zilberg, a fish research specialist and senior lecturer at BIDR’s French Associates Institute for Agriculture and Biotechnology of Drylands. “The ornamental industry is high-tech and more profitable.”
Pet fish find a ready market in Europe. Although the Israeli-raised aquarium fish are more expensive than those from competing suppliers— mainly based in Singapore—they are valued for their health and resistance to disease. This is the province of Dr. Zilberg, who combines her own research on parasites and infectious disease with support for farmers when their fish have problems. The research focuses on creating ideal conditions for fish, she explains, and keeping them healthy. Because the environment is closely controlled, the fish farms provide unusual laboratories for studying problems.
“I’m pretty sure that everything comes up In nature—diseases are always there, but we may not see them,” Zilberg says. “When viruses arise in the natural environment sick fish can easily be missed and often are preyed upon. But aquaculture is so intensive that you see what you would in nature, but much more.”
For example, responding to a fish farm problem, Zilberg recently studied a protozoan parasite that becomes systemic in guppies and may serve as a model for other, similar parasitic infections. In researching its interaction with the host, she found a treatment for the disease.
Longer range, she hopes to develop an oral vaccine. Another ongoing project involves using microalgae to stimulate the fish’s own immune system. And recently, she has been investigating unusual tumor-like lesions in clownfish, never before reported.
How Basic Research Helps
Dr. Marcia Pimenta Leibowitz is a fish health specialist who earned her M. S. and Ph.D. at BGU, working with Zilberg. With experience managing aquaculture for a government lab as Well as private research facilities, she is now responsible for fish health at Colors, an area company that grows tropical fish, shrimp, koi and other organisms for aquariums.
She notes that the University’s basic science resources are instrumental to The industry’s development. Prof. Sammy Boussiba, director of the French Associates Institute, for example, who has no direct interest in fish farming, provided a specific algae that is critical to the lifecycle of some shrimp and fish. “Without that we couldn’t grow many of these creatures,” she says.
Plant specialist Dr. Rivka Ofir, of the Faculty of Health Sciences’ Department of Virology and Developmental Genetics, shares her library of plant extracts. Their medicinal properties can be used to treat fish disease.
Leibowitz continues to collaborate with BGU researchers as well as those at other Israeli and American universities. Israel is the right place to be, she believes, because, “It’s always up to the challenge, very driven to do the next best thing, especially in aquaculture. BGU is cutting edge because it’s newer and growing. But there’s still a lot to do. BGU has a huge role.”
Like Zilberg, she appreciates the research opportunities the farms offer. “All over the world fish grow in nature. In Israel, we grow them in greenhouses—so we have much more data: such as how many fish die, how much food they need based on body weight.” She is currently exploring how to produce specific pathogen-free goldfish in closed biosecure systems all year round. Traditionally, goldfish are reared worldwide in open ponds where they only breed seasonally.
Fish grown in closed systems where conditions are controlled are healthier, she says. “If you give them high quality food and a good environment and the husbandry is OK, they will not get sick. You use the least chemicals you can.”
And for the future, the importance of expertise in fish farming can only grow. “How long can you keep taking fish and shrimp from the wild?” Leibowitz asks. We need also to ensure that fish are healthy to eat. “We need biosecure fish in the future—fish that are resistant to pathogens. You can only get this through research.”
Appelbaum also sees a big role for fish farming in the Negev and other arid lands: “The gap between availability of fish from the ocean and the increasing demand globally can be breached by aquaculture. It’s not a revolution—simply sensible utilization of resources. As pioneers we can show others how to do it. Students come to our school for desert studies from less developed countries all over the world to study everything about arid lands, including fish farming. We expect them to return to their homelands and benefit from our investment.”
He champions a major shift in thinking: “We’ve been seeing all the arid lands around the world as useless and infertile, and poverty is the result. We have to forget that and see the opportunities—opportunities like the subsurface water that is often there and can be used to feed the nations.”
This article was originally published in the Spring 2012 issue of AABGU’s Impact magazine. See more stories here >>