Print This Page


Steven Serfling



Steve Serfling, a career aquaculturist, best known for his work with tilapia, snook and wastewater treatment, died of cancer on February 15, 2007.  He was 62.


One night in September 1976, Steve and his business partner at the time, Dominick Mendola, scribbled down some aquaculture concepts that eventually led to trials with “bio-floc” shrimp farming.  In the late 1970s, they built a zero-exchange, intensive, bio-floc, shrimp farming system capable of producing roughly 20,000 pounds of shrimp per acre per year, but no one would believe their numbers, and they could not get investors to buy into the concept.


Fortunately, Steve lived long enough to see the shrimp farming industry adopt many of his ideas, especially those on bio-floc shrimp farming.


In 1973, Steve and Dominick started Solar Aquafarms (SAF), a closed system tilapia farm in Southern California that was eventually purchased by Chiquita Brands (the banana people), which invested $10 million in the project.

Stanley Serfling


On April 19, 2007, I interviewed Stanley Serfling, Steve’s younger brother by ten years.  He worked with Steve at Solar Aquafarms.


Shrimp News: I didn’t know Steve very well.  What kind of person was he?


Stanley Serfling: Steve was my mentor and my older brother.  We were raised in Libertyville, Illinois (north of Chicago, home of Marlon Brando and Adlai Stevenson).  Steve went to Libertyville High School and then to nearby Northwestern University in Evanston, one of the top universities in the United States.


Steve really liked to try new things and new ideas.  He went from prawns to tilapia to wastewater aquaculture.  Since he was always into the next new thing, he had a tendency to leave unfinished business behind.  While he was open to ideas from others, he also liked to do things his way and wanted to make a financial success of his aquaculture career.


Shrimp News: When did he get the aquaculture bug?



Steve at 13 or 14

Stanley Serfling:
As a teenager and young man, he was interested in fishing, snorkeling and scuba diving.  He loved the old TV show, Sea Hunt, with Lloyd Bridges.  Before I was born, or when I was too young too join them, he and Dad went fishing a lot.  I think his aquatic interests came from my father.  Everything they caught they ate, that’s the way my father was raised.  But the biology program at Northwestern was all about premed, nothing about the environment or wildlife or fisheries.  In 1965, between his junior and senior year, when he had one semester to go to get his degree from Northwestern, he transferred to San Diego State University in California.  That year my parents and my other brother Scott were living in Japan, where Dad, a high school teacher, had taken a job at an American school near Tokyo.  Steve never would have been able to do that if Dad had been around.  It took him another year and a half to get his degree because he took extra courses in marine biology.  He said San Diego State had a great marine biology program, excellent professors, and he really loved it there.  That’s when he made a commitment to aquaculture.  He got involved in scuba diving with classmates Jim Carlberg and Jack Van Olst, who later became partners in a successful striped bass farm.  He got his bachelor’s in marine biology in 1968 and a master’s in 1970, doing much of his research on lobsters at Scripps Institution of Oceanography.  Joan Mitchell, a graduate student at San Diego State, who had a long career with the National Science Foundation, did her master’s at the same time as Steve.


After getting his master’s degree, he went to the Virgin Islands, and did a yearlong study on spiny lobsters and their migration patterns.


From 1972 to 1974, he was enrolled in a Ph.D. program at the University of California, Davis, in aquatic ecology.  Tony Schuur, currently an aquaculture/shrimp farming consultant, was in the same program.  Steve never completed the Ph.D. program.  He felt that he just didn’t need it to do what he wanted to do.  Later, however, after he left Solar Aquafarms, he thought about restarting his Ph.D., but didn’t, and later said that that was a mistake.


In grad school, he worked with lobsters, but shifted to freshwater prawns when he realized that lobster farming was not going to be feasible.   He started Solar Aquafarms in 1973 with Dominick.  The seeds of SAF had been planted in 1969-70, down in San Diego, when Steve moved into Dominick’s “Huron Labs” house, where they built their first miniscale backyard greenhouse and closed-system, multitrophic-level fish system.


Shrimp News: Did Steve strike it rich when Chiquita Brands bought Solar Aquafarms?


Stanley Serfling: Chiquita invested $10 million in that project, but Steve did not strike it rich.  He had a good salary and would have made a lot of money if the project had succeeded, but it was only marginally successful.  When a storm did a lot of damage to the greenhouses, Chiquita, which had just lost its European banana business, took the insurance settlement and closed the farm.  Steve’s plan was to move the tilapia production overseas to lower the cost, but Chiquita would not approve this move.  Chiquita attempted to import tilapia filets from Colombia, which worked for a while, but then the quality at the farm diminished and that was the end of that experiment.


Shrimp News: What did he do next?


Stanley Serfling: One of Steve’s most successful projects was in 1983, for a distillery plant in Madras, India, that wanted to do something with its coffee-colored effluent.  Steve designed a very successful tilapia farm for them.  The distillery effluent was treated in an anaerobic digester for 24 to 48 hours, then flowed into aerated ponds where it was bioconverted to algae, then fed to fifty hectares of tilapia ponds.  It was their only source of feed.  It really worked well and was one of his best projects, if not his best.


In 1991, he left SAF and worked in Mexico for a couple of years.  Then, in January 1996, he went to Florida and took a job as director of aquaculture at the Mote Marine Laboratory.  He did some impressive work there and brought the lab some great publicity.  The state of Florida was collecting several hundred thousand dollars a year from a snook (a prized sport fish) stamp on fishing licenses, and Mote was giving the state several hundred thousand a year to hatch and release snook.  The state collected snook eggs and hatched them out, but it couldn’t keep them alive and never produced any juveniles.  So Mote stopped giving the money to the state and gave Steve $300,000.  He built a little hatchery, captured some wild gravid snook, spawned them, collected their eggs, and within a year had 10,000 12-inch-long fingerlings that he released into the bay over several months.  His production numbers kept going up after that first release.  Steve wanted to raise and sell snook, but it was illegal because it’s a sport fish, a protected species.  When Steve left Mote, the new director decided to change the system around by adding mechanical filtration to clean the “dirty water” and the result was a significant drop in the number of snook releases.


After Mote, he worked for a sturgeon farm in Canada for about a year, and that went pretty well.  He came back to Florida and was very busy doing consulting work in North Carolina and Florida when the cancer intervened.


Shrimp News: When was that?


Stanley Serfling: He had some patches of skin cancer removed in the late 1980s, and in the early 1991 he had a dime-sized patch of skin cancer removed from his back.  In 2005, he had surgery for colon cancer.  Sixty percent of the people that have colon cancer suffer a reccurrence somewhere else in their body.  With Steve, it showed up in a lung and then in his bones during the summer of 2006.  He had radiation treatment, but kept getting weaker and weaker.  He knew he was going to die, but didn’t stop working until the very end.  He died on February 15, 2007, 36 hours after going into hospice.

Dominick Mendola


On April 26, 2007, I interviewed Dominick Mendola, Steve’s partner at Solar Aquafarms and the inspiration for most of their work with shrimp.


Shrimp News: What kind of guy was Steve?


Dominick Mendola: When I first met Steve in 1969, he was your typical handsome, sun-tanned, “diver-type,” marine studies student.  He was working on a Sea Grant Homarus lobster project with Jack van Olst and Jim Carlberg at Scripps Institution of Oceanography.  Steve was fun to be with and liked to talk about how neat it would be to set up his own commercial aquaculture business.  He got his chance when we incorporated SAF, in Encinitas, California, in 1976 (after the failed start with the Heineman project in 1973).  Steve was an overly confident, brash, young CEO preaching “my brand of aquaculture will someday rule the world”!  It worked!  He managed to talk a lot of people into investing their money, including Chiquita Brands, which bought into Steve’s story of “a tilapia on every plate” in 1980.


When we started SAF in 1976, we advertised in the local paper for a “Girl Friday to be the President of a startup aquaculture business in Encinitas.”  A recently divorced mother of two came to interview and won the job.  Her name was Virginia Wahl (later changed to “Waters”), and in due time she and Steve became “a unit.”  She was into “psychic/spiritual” self-investigation and Steve got intrigued.  It changed him immensely, and for the rest of his life he went through a neverending personal transformation, becoming less self-centered and more holistic and spiritual.  The Steve in the early days was a very different guy from the Steve in the later days.  Humiliation by life?  He trained himself to be more easygoing, and he succeeded.


Shrimp News: Why didn’t you receive more acclaim for your early work with bio-floc aquaculture?


Dominick Mendola: I think we would have gotten more credit if we had published more information on what we were doing.  Later in his career, when Steve published some of his ideas, everyone thought it was great stuff.  When you see it on paper, it’s more credible than when you just hear about it.  If we had published some drawings and methodologies, it might have helped, but that’s water under the bridge now.  It is interesting that ecological methods are coming back into vogue now.  Ecology means long-term economics, sustainability; we really didn’t understand sustainability in the 1970s.  Now the world demands long-term, sustainable business models. SAF was an attempt at an eco-based kind of business.  It worked, but was about 30 years ahead of the curve.


Shrimp News: Who were some of your classmates at San Diego State?


Dominick Mendola: Jack Van Olst, Jim Carlberg and a bunch of other guys and gals (like Joan Mitchell) were in the same class with us, with the same professors.  Jack and Jim founded the successful striped bass company that is now Kent SeaTech.  Joan Mitchell went on to a Ph.D. at the University of Washington, then to Washington, D.C., and a lifelong job with the National Science Foundation.  We all took slightly different paths.  We all got the same instruction from the same instructors.  It paid off.  As a group, we all went on to have successful careers in aquatic and marine biology.


I took the aquatic freshwater route and was influenced by the New Alchemy guys, John Todd and Bill McClarney, who were teaching multitrophic-level aquatic ecosystems.  What Steve and I did was apply their concepts to a tank in a greenhouse.  We tried to capture our knowledge of aquatic ecology in a tank.  That’s basically how we got started.  Our professors were just great in inspiring us to look deep within the water column for business solutions.  Steve and I had a real talent for turning our dreams into workable aquatic systems.  We worked like mad—seven days a week for years and years—until it culminated in the successful Chiquita tilapia farm in Sun City, California.  Steve was an innate aquaculturist, a natural.  He didn’t need a Ph.D. to tell him what was going on in a tank.


Shrimp News: Did you really come up with your aquaculture concepts in one night?


Dominick Mendola: Yes, that was an amazing night; I can still feel it today.  It had an electric air to it that was very unusual.  Steve and I worked very well together.  Our brains became almost one.  From after dinner that night, to about three in the morning we turned out about 23 pages of densely packed, new ideas that became the blueprint for SAF—and our careers.  The bio-floc idea came later (about 1977-78) after we had built our thirty-foot-in-diameter, intensive tilapia tanks at SAF in Encinitas, and we were just getting into marine shrimp.  That’s when we started playing around with intensive bio-floc systems.


We had a damm good education at San Diego State University and knew almost intuitively what was going on with the bacteria and the invertebrate trophic levels in the tank.  Our instructors really took us in hand and were really good about teaching aquatic ecology—both as basic science and as applied to aquaculture.  It was the pre-Reagan era when education in California was just going gangbusters and our education system was world renowned.  We spent a lot of time with our professors, after hours, day and night.  I remember sleeping at school many nights because I was just going to come back in the morning.  We were immersed in an academic program that really taught us aquatic ecology, from the inside out, bacteria first.  Yes, we knew what we were talking about, and I have to give a lot of credit to our professors.  In that one night, we put down on paper what was to become Solar Aquafarms and the basis for our careers in aquaculture and marine science.  After that first night, all we did was find-tune it and then find-tune it some more.


Shrimp News: How did SAF get started?


Dominick Mendola: Steve and I started SAF in our conversations and in our minds long before it became a legal business entity.  We actually started it when we first met each other at San Diego State and Scripps Institution of Oceanography in 1969.  We didn’t coin the name “Solar Aquafarms” until about 1973, up at our Woodside, California, house.  I said “I’m not cut out for working at a pharmaceutical company,” and Steve said “I’ve had it with this Ph.D. program” (at the University of California, Davis).  Steve said, “Let’s do it.  Let’s start a company right now.”  We got out a piece of paper and started throwing “eco-words” onto the page and “Solar Aquafarms” popped out.  The name embodied just what we wanted to do, use the sun’s free energy to grow food in aquatic ecosystems.  Without a cent, we got out another piece of paper and wrote down our business plan.  Then we went out in the backyard, and with shovels and rakes we leveled out a spot and built a small greenhouse, put some tanks in it and added a freshwater prawn (Macrobrachium rosenbergii) stacked-tray system that Steve had been working on in his backyard in Davis, California.  We always had little extracurricular greenhouses and laboratories at our homes, along with tanks and greenhouses with fish and shrimp in them, even when we had other jobs.  That infrastructure became SAF, and we focused on freshwater prawns in the beginning.

Stan Serfling took this picture at Solar Aquafarms' facilities in Encinitas, California, in 1980.  Famed actor Eddie Albert (April 22, 1906 – May 26, 2005) had read about the project in the Los Angeles Times an drove down from L.A. to check it out.


We used Steve’s stacked-tray system that housed one prawn per container, hooked a solar panel to it, dumped in some hydroponic tomatoes, and by golly we had a cookin little freshwater system that worked quite nicely.  We would sprinkle the food on the water surface, and it would trickle down to the food platforms below, where the prawns would eat it.


In 1975, we moved to Encinitas to work for Peter Heineman and his godfather, Richard Solomon, who was the money guy behind a cosmetic company in New Jersey.  They invested about $75,000.  We grew Macrobrachium in a solar-heated greenhouse, using a closed system and stacked trays.  It worked quite nicely, until the project imploded when the Heinemans thought it was time to demote Steve and put the young son Peter in as head of the project.  Steve said “No-way,” and called me from New York to tell me to start moving the broodstock over to our nearby house and backyard greenhouse.  The project with the Heinemans collapsed.


Shrimp News: Were you at SAF when the shrimp work was done?


Dominick Mendola: The marine shrimp project was my baby.


We restarted SAF in the backyard of a little house in Encinitas.  Our parents put up some money, and we also got some money from a retired businessman in Rancho Bernardo, California.  Around 1976, we built a bigger greenhouse and switched to marine shrimp (Penaeus vannamei) because we had read about some successful P. japonicus farming in Japan.  We figured that there could not be that much difference between japonicus and vannamei.


Earlier, when I was at Syntex, a pharmaceutical company that had a freshwater prawn project in Mexico, I had made contact with a father and son team in Mazatlán, Mexico, José Angel and Don Angel Castro.  We tried to put a Macrobrachium farm together with them, but it just didn’t happen.  They were also working with marine shrimp (Penaeus vannamei) to see if it had any aquaculture potential.  This was in 1972 or 1973, very early in the development of shrimp farming in the Western Hemisphere.  I called Jose Castro, and asked him if he could send up some vannamei broodstock.  He did better than that, he drove them up to the border, flashed his department of fisheries badge and walked them across the border.


We took them to our Encinitas greenhouse, which had been primed to receive them.  The water was fifty percent natural seawater and fifty percent artificial seawater.  We had seeded it with all kinds of marine organisms that we had picked out of the local bays.  We put the broodstock in there and fed them very well.  And they did well, matured, mated and before we knew it, we had gravid females.  We built a separate little hatchery and spawned them.  It was really exciting.  We got larvae, but could not get them through all the PL stages.


Our bio-floc growout system was doing well and we were pretty confident that we could produce 20,000 pounds of shrimp per acre per year, but we were getting a lot more out of our freshwater tilapia system.  We did not want to give up on marine shrimp, but our investors and potential investors (Chiquita Brands) told us that we had to pick one species, and we choose tilapia.  We were getting amazing yields from our tilapia floc system.  When you looked at the numbers, it was a fairly easy choice to go with tilapia.  The investors liked that and that’s what we sold to Chiquita Brands.


Shrimp News: Did you ever get into the tanks with the fish and shrimp?


Dominick Mendola: We would get into the tanks with the with a hooka air tube and a face mask and just sit there for hours observing the animals.  We would write down on our underwater pads exactly what they were doing.  We matched what we were observing with our academic knowledge and textbook learning.  It gave us a really good idea of what our animals needed to grow and prosper.  That’s a very simple key to aquaculture, but not many people do it.  We did it for hours and hours on end.  We always got into the tanks.  Steve always knew how to keep the animals happy.  He understood what the animals needed, and so did I, and our ideas always meshed very nicely.

Steve Serfling


At the World Aquaculture Society (WAS) Meeting in San Diego, California, USA (January 27-31, 2002), I interviewed Steve Serfling.  At the time he was president of Sunwater Technologies, a consulting company in Florida that specializing in recirculating aquaculture systems.


Shrimp News: Hi Steve.  Tell me a little bit about the pioneering work you did with shrimp in closed systems in the late 1970s.


Steve Serfling: During the early R&D years at Solar Aquafarms, from 1974 to 1984, the goal was to develop closed-cycle, controlled-environment, ecology-based systems for culturing fish and shrimp.  Various types of low-cost, solar greenhouse covered raceways and circular tanks were developed to allow year-round production in cold-winter climates, like the USA.  Many types of aeration and biofiltration were tested to allow the higher production rates required to justify the higher capital investment in the culture system.  We first experimented with the freshwater prawn, Macrobrachium rosenbergii, and tilapia during the mid-1970s.


Shrimp News: What got you started with marine shrimp?


Steve Serfling: At that time no one had been able to raise marine shrimp to normal market sizes or to breed them in recirculating tanks.  Macrobrachium had immediate potential if we could overcome a density/cannibalism problem.  We tried by developing several types of horizontal and vertical habitats, plus aeration and currents.  These additions allowed us to obtain Macrobrachium yields equalling 10,000 pounds/acre/year, but that still represented a marginal return on investment.  So we switched to marine shrimp, Penaeus vannamei.  We calculated that if we could achieve yields of 20,000 pounds/acre/year (say three crops at 6,000-7,000 pounds each), and sold the shrimp head-on, the technology would work financially.


Shrimp News: What led you to develop your unusual “microbial soup” water treatment method?


Steve Serfling: We started out testing a variety of conventional water treatment methods and equipment, like trickling filters, submerged biofilms, slow-sand and pressure-sand filters, clarifiers, UV and ozone—all designed to remove solids from the water and keep it clear and sterile.  But during a visit I made to several highly productive shrimp estuaries and ponds in Ecuador and Costa Rica, it was obvious that shrimp, at least P. vannamei, grew very well in water with high levels of suspended algae and detritus.  So we threw out the filters, clarifiers and sterilizers and duplicated the rich estuary ecosystem in our tanks.  The nickname that stuck for the treatment process was “ODAS,” for “Organic Detrital Algae Soup,” a mixture of hundreds of different species of microalgae, beneficial bacteria, detrital flocs, protozoans and zooplankton that thrive on shrimp wastes.


Shrimp News: Did you plan to have the shrimp feed on the bacterial flocs?


Steve Serfling: No, that was an accidental discovery.  I’d heard that vannamei grew well in low-density ponds even without commercial feeds, growing just on the natural foods in a pond.  But I was curious about how it compared to other species.  So we did feeding tests with monodon, stylirostris and vannamei in aquaria.  We discovered that vannamei would eat all kinds of detritus that the other species would not touch.


Shrimp News: How did you discover that vannamei can filter algae like Spirulina directly from the water?


Steve Serfling: During that period we were also raising Spirulina algae on a research and pilot commercial scale.  We put some live Spirulina in an aquarium with juvenile vannamei and to our surprise the shrimp immediately rose up in the water column and started filtering out the Spiriulina, using a fan-shaped filtering appendage with fine hairs, similar to how barnacles (also crustaceans) feed.  Within five minutes they had filtered all the Spirulina out of the water, their stomachs turned green and you could watch it pass though their systems.  Vannamei appears to have adapted over millions of years to filter zooplankton and large microalgae from the water column.  But Spirulina is too expensive to grow as shrimp feed, so we looked at other alga species.  We learned that regardless of how small the microalgae were, as long as they were attached or trapped in detrital flocs, either suspended or settled, or on biofilms on the sides or bottoms of the tanks, the shrimp would consume the algae, either by picking or filtering.  When filtering, they would either swim after the flocs or simply stand on the bottom and sweep them into their mouths.


Shrimp News: I visited your facility during that period and remember you saying, “the water column is the filter.” I thought you were crazy.


Steve Serfling: You weren’t the only one who thought we were crazy!  Even though we showed people the “biofilter,” they were convinced we had some elaborate system hidden behind the greenhouses.  We did test the vertical and horizontal substrates originally made for Macrobrachium on the vannamei, including one that was almost identical to the current “AquaMats” product.  In fact, we even obtained a patent for a water treatment process that uses vertically suspended biofilms as a key component.  But at the densities we targeted at that time with vannamei (7,000 pounds/acre/crop with three crops a year), substrates provided no significant benefit.  They may be helpful at much higher densities.


Shrimp News: How did you aerate?


Steve Serfling: With diffused air lifts and sometimes paddlewheels and the recycle water jet.  One thing we learned early on was that you had to have continuous mixing and aeration to keep solids in suspension.  Otherwise, anaerobic pockets and the resultant hydrogen sulfide would kill the shrimp.  In those days, critics said aeration was too expensive for raising shrimp, but our analysis indicated that our aeration only added about $0.06 to a pound of shrimp.


Shrimp News: What salinities were you working with?


Steve Serfling: We tested salinities from 3 to 10 parts per thousand (ppt), and the shrimp appeared to do equally well at 3-5 ppt as at 10 ppt.  We knew that vannamei could tolerate low salinities, but at that time we thought it too risky to raise them in freshwater.  It was a closed system, so the cost of salt for 3-5 ppt was very minor.


Shrimp News: In recent years several of the technologies that you pioneered 20-30 years ago, namely the suspended microbial treatment process, continuous aeration and mixing, high culture densities, and greenhouse covered raceways, have turned out to be the right direction.  Why didn’t you scale-up back then to an intensive commercial shrimp operation?


Steve Serfling: The problem we ran into was not with the technology or demonstrating, at least to ourselves, that shrimp could be grown in closed-cycle, greenhouse-covered tanks at high densities.  The problem came when potential investors tried to get independent confirmation on our technology and financial projections.  All of the shrimp “experts” they contacted (primarily university professors or government employees) laughed at our proposal and said yields of 20,000 pounds/acre/year were impossible to achieve, aerated ponds or tanks were cost prohibitive, and recycled water wouldn’t work.  At that time shrimp ponds in Ecuador were getting only 500 to 1,500 pounds per acre.  So we could not raise the funding.


Shrimp News: What do you think the future holds for farming shrimp in intensive systems in cold-winter climates like the US?


Steve Serfling: I think the potential is very good.  The USA produces the lowest cost poultry in the world, not because labor is cheap, but because we combine the lowest cost feeds with the best technology.  The same advantages could apply to shrimp.  Given current economics, the yield of shrimp would probably now have to be about 20,000 pounds/acre/crop with three crops a year to provide an attractive return-on-investment.  But those yields and greater have been achieved by others with modern intensive systems.  With fish such as tilapia, hybrid striped bass and sturgeon, I have frequently grown them at densities equalling 300,000–500,000 pounds/acre/year using the same technology.  So maintaining good water quality for shrimp with an “ODAS” type process is not a problem.


Source: Bob Rosenberry, Shrimp News International.  July 31, 2007.


Print This Page