Group Summaries - Alternative Culture Methods

May 22-24, 2006 UF Tropical Aquaculture Laboratory

Attendees: There were 30 participants from 13 institutions.
Facilitator: Jimmy Avery (NWAC)

SESSION SUMMARY:

Claude Reeves (Auburn) discussed a research/extension project with freshwater prawns cultured in 1,500 gallon tanks. Very few large prawns were produced with a range of 1 to 30 grams. The prawns in the system had a poor feed conversion ratio. Total production was around 20 to 25 pounds/tank with survival of 55 to 60%. The system incorporated substrate, one horsepower of aeration, and a 2 acre pond for water quality maintenance. The take away message for clientele is that the system has been tried but it is just not feasible for production. The system may have potential for either for nursery or temporary holding.

Craig Tucker (NWAC) discussed the modified Partitioned Aquaculture System (PAS) currently being investigated in Stoneville. The system uses 0.15 acre for sequestering fish and 0.85 acre for water treatment. The temperature remains fairly consistent due to mixing. He has used hybrid catfish in the system for the last two years. He feels that the combination of the more resistant hybrids and using smallmouth buffalo as a biological control agent has significantly reduced the impact of proliferative gill disease. The system yielded a net production of 16,500 pounds/acre in 2005. Off-flavor is still a problem. NWAC is now developing a larger, modified Clemson system.

June 6-8, 2004 University of Arkansas, Pine Bluff Attendees: Jim Rakocy, UVI; Lou D’Abramo, MSU; Steve Mims, KSU; Alex Kahovski, UAPB; Robert Romaire, LSU; Ray McClain, LSU; Peter Woods, TAMU; Jesse Chappell, AU; Hugh Thomforde, UAPB; Forrest Wynne, KSU; Patricia Duncan, FVSU; Nathan Stone, UAPB; and George Sheldon, UAPB. Facilitator: Bauer Duke, UAPB Co facilitator: Sathynand Kumaran, UAPB SESSION SUMMARY: Areas discussed:
·	Current methods in use and spin-offs
·	Considerations used in presenting new systems to fish farmers
·	Variability of climate throughout regions where experiments are conducted
·	Use of bacterial based systems, algal based systems, and combined systems
·	Satiation feeding
·	The PAS system
The group looked at different methods currently in use and spin-offs of those methods in describing Alternative Methods of Culture. Concepts were taken from the Circular Autotrophic Bacterial System With Side Solids Removal (CABSWSSR) and the Aquaponics system studied in the Virgin Islands using tilapia; a trout raceway system used in Idaho; the PAS system using catfish and tilapia; and a spin-off of the PAS used in Louisiana with catfish. The group discussed considerations when spreading the word of new systems to fish farmers. The system has to work the first time a farmer uses it. This means our small experimental systems need to be scaled up and proved at the commercial level. We asked, “What defines a commercial unit?” If a farmer supplying fish to the live market needs 20,000 pounds in a week, a commercial unit might be one that produces that quantity. However, a commercial unit for a catfish producer sending fish to the processing plant has to be able to fill a truck with 40,000 pounds. We discussed the variability of climate throughout the region where experiments are conducted. We have to be careful about moving tropical culture methods to the temperate zone. The move is possible, but the economics need more study before the move is made. Aquaponics is currently used in the tropical and temperate zones, and in markets where the plants grown fetch high prices. Indeed this system emphasizes plant growth over fish growth. We discussed the use of bacterial based systems, algal-based systems and combined algal/bacterial systems. All have a place in aquaculture, but not all can be used in all places or at all commercial levels. Our role is to find out where these alternatives might be applied. Bacterial based recirculation systems are able to produce tilapia at an order of magnitude greater than the CABSWSSR, but the latter can be constructed much cheaper, and the operation costs are less. If the CABSWSSR is placed in the temperate zone, it must be able to run year-round and the use of cover, be it buildings or greenhouses, must be employed. Just as high value herbs are produced with Aquaponics, a by-product is created with this system. The captured solids have been referred to as liquid gold by farmers using them on their fields. It’s cheaper than inorganic fertilizer and seems to release nutrients into the soil more slowly. Nutrient activity was present one year after application. Satiation feeding is currently conventional wisdom in most aquaculture sectors, but may not always be the best alternative. The Idaho trout industry ceased satiation feeding for their fish to comply with EPA effluent regulations. No longer do the fish determine how much they will eat. The FCRs are down, the effluent complies with EPA regulations and the farmers are making more money. The PAS system continues to attract researchers as a problem-solving device for catfish farmers. Concentration of the fish allows for easier feeding, harvesting and less area to protect from birds. The system prevents large shifts in water quality. This was also found with the CABSWSSR, although nitrate remains a problem to be dealt with. The PAS was altered on a farm in Northwest Louisiana and shows promise. The beauty of this system is the conversion of a conventional 6-acre catfish pond into this alternative method. A question that came up here is, “Can you recommend a patented system, how does the farmer get hold of it, and how much does he need to change it to get around the patent if the patent becomes an obstacle?” In most systems mentioned, pond soils have been eliminated as a confounding element in water quality. Further alternatives to earthen pond aquaculture may be reshaping the ponds and using liners. This will assist in creating flow, enhancing aeration, eliminating stratification, eliminating blue-green algae, and stabilizing water quality control.

March 15-16, 1999 Kentucky State University Attendees: Representatives from nine states Facilitator: Michael Masser SESSION SUMMARY: All states reported intensified research and/or extension efforts in four basic areas:
	·	high school aquaculture education
	·	recirculating systems
	·	cages and net pens,
	·	raceways (including the PAS or Partitioned Aquaculture System).

·	Auburn University representatives reported on cage culture of both catfish and tilapia by small-scale producers and raceway culture of catfish fry to reduce predation. They also reported on working with several high schools on development of aquaculture education.
·	Clemson University reported on research and extension efforts with the SC marine shrimp industry. Most of this research centered around reducing discharge of effluents through utilization of oysters and clams as biofilter organisms and sludge collection and reuse. Clemson also reported on culture of mud minnows.
·	Clemson University and Louisiana State University both reported on the PAS system research and private PAS production facilities. Dr. David Brune at Clemson has obtained a patent on the PAS system and is licensing its utilization for both research and commercial production. LSU also reported on recirculating research by Dr. Ron Malone and production by private tilapia facilities in Louisiana.
·	The University of Florida reported on a modified above-ground raceway system that utilizes a partitioned pond as a biofilter. U of FL also reported on research on culture of gulf sturgeon.
·	Kentucky State University reported on utilization of water from abandoned coal mines to produce trout and polyculture of catfish and paddlefish. KSU also reported on culture of largemouth bass and macrobrachium.
·	North Carolina State University reported on recirculating systems research and development of commercial tilapia facilities based on this research. NCSU also reported on commercial cage and net pen production and research utilizing a gravity-fed, flow-through system that uses recirculating system components for waste capture.
·	The University of Tennessee reported the completion of an aquaculture research facility which will work on small-scale systems with emphasis on recirculating systems and flow-through systems with water conservation. Both warm and cool water species will be studied.
·	Texas A&M University reported on work with marine shrimp producers in reducing effluents through the use of man-made wetlands and reduction of stocking densities and feeding rates.

March 15-17, 1998 Clemson University Attendees: Fourteen individuals were present from South Carolina (Clemson), Mississippi State, Auburn, University of Florida, University of Tennessee, and the University of Georgia Facilitator: David E. Brune SESSION SUMMARY:
·	Two individuals reported an interest in Partitioned Aquaculture System (PAS) type applications for baitfish production to eliminate harvest problems in ponds.
·	Arnie Eversole reported on mussel growth in a PAS configured system, with 95% survival and 1 mm/week shell growth. He also suggested that mussels enhance bluegreen algal dominance in the system as compared to tilapia, which tend to reduce or eliminate bluegreen algal dominance.
·	David Brune reported on the successful use of brine shrimp to harvest algae in a PAS system.
·	Chuck Weirich reported ont eh installation of PAS units at LSU.
·	Craig Tucker reported on side scanning sonar to ascertain fish behavior and response to dissolved oxygen in ponds and the use of electric fields in enhancing fish harvest.
·	Jaw-Kai Wang reported on the algae/oyster/shrimp co-culture system in tank systems in Hawaii. He discussed the importance of maintaining steady state with balanced biomass levels and continuous algal harvest. He indicated that the commercial farms are receiving $10/lb for heads-on shrimp and 15-85¢ apiece for oysters. However, capital costs in Hawaii are $45,000/acre to prepare land.
·	Jeff Hinshaw at North Carolina State reported on a new version of the intensive tilapia production (fish farm) system run by Carolina Power and Light. He also reported on Macrorachium/trout hatchery system using warm water in summer for prawn production and cold temperatures in winter for trout production.
·	Rick Wallace at Auburn reported on early work with in-pond raceways using airlift pumps growing oysters in bags. There was further discussion on PAS systems concerning reduction of costs, and possible ultimate carrying capacity.

March 24-26, 1997 University of Tennessee Attendees: Not available Facilitator: Jeff Hinshaw SESSION SUMMARY: Twenty persons representing eleven states met to exchange information on alternative culture methods. Following introductory comments and general agreement by the group that at present, most alternatives to traditional methods of pond and tank culture had not yet been proven economically viable, the following individuals reported on activities from their respective states or institutions:
SOUTH CAROLINA
·	Rocky English presented an update on the Partitioned Aquaculture System research at Clemson. Catfish were produced at densities approaching 15,000 pounds/acre in the confined portion of the system in the 1996 growing season, and tilapia had been produced in the partitioned area of the ponds. Photosynthesis was measured at 3 to 4 times higher than in traditionally managed ponds for catfish. Rocky handed out summary sheets showing specific measurements of chemical and production parameters from the system. Later in the discussion, Rocky inquired as to whether anyone had experience with infestation of psychodid flies (moth flies) in biofilters. The larval flies caused clogging and reduced performance of the filters in their recirculating systems at Clemson when they reached high numbers.
ALABAMA
·	Michael Masser reported on research with in-pond raceways for catfish production. In the previous season, tilapia had been added downstream from the catfish in the systems to determine their impact on waste capture in the system and the potential for polyculture in these systems. The tilapia grew nearly as well in raceways where they were not fed as they did in raceways where they were provided with a prepared diet. Four species of freshwater mussels were tested in the raceway systems and three of the four species performed very well, gaining as much as 20% of their volume in the test period. The mussels are typically harvested for shell production. Plans are to include carp in the systems in 1997. Ron Phelps reported testing the in-pond raceway systems in brackish water using tilapia. At 14 ppt, tilapia production reached 120 kg/m3 in 90 days.
ARKANSAS
·	Carole Engle reported on a planned project using a combination of pond culture and circulation through a wetland cell for management of water quality. The project is scheduled to begin later this year. Carole also reported on testing of in-pond biofilters (Perschbacher) taking place in Arkansas.
At this point, considerable discussion followed on the advantages and disadvantages of circulation in ponds, including the partitioned systems, in-pond raceways or biofilters, and circulation through various pond 'cells'. The economics of pond circulation for increasing production is currently inadequately defined, however, the consensus of the group was that if off-flavor could be reduced or eliminated using these methods, then the added costs of moving water most likely would produce a favorable return.
TENNESSEE
·	Bill Simco made a 'tongue-in-cheek' request for development of a bio-filter system based on 'sweetgum balls', preferably from his yard! Some discussion ensued regarding the fact that they are virtually indestructible, plentiful, and have high surface area, and that Bill should patent the idea.
NORTH CAROLINA
·	Jeff Hinshaw reported on studies evaluating seasonal production of coldwater species (rainbow trout and Atlantic salmon) in net-cages placed in small temperate impoundments. To date, production levels approaching 1,000 pounds per surface acre have not resulted in significant water quality changes in the impoundments. The primary influence on levels of phosphorus in the systems is the level in the inflowing stream. Plans are to increase the production levels to approximately 2,000 pounds/acre in 1997/98. The systems are based on stocking the fish in October with complete harvest in May each year. The pens are left empty during the summer. Jeff also reported on development work at NCSU by Tom Losordo on economical de-nitrification systems for use with recirculating aquaculture facilities. This work has just started and should proceed through 1997/98.
ALABAMA
·	Dave Cline described the cage culture industry for production of catfish in northern Alabama. Approximately 200 to 250 producers are growing catfish or are holding the fish for stocking or processing typically in rectangular cages in small impoundments.
Finally, the question was raised to the group as to whether there were any successful commercial recirculating aquaculture systems still operating in the US. Some facilities were mentioned, but no definitive number was agreed upon. The need for economic evaluation of pond systems using recirculation to enhance productivity or improve water quality was reiterated by most in the discussion group. The group adjourned following a chance for announcements of future workshops or other items of interest.

March 24-26, 1996 University of Arkansas, Pine Bluff Attendees: Not available Facilitator: Les Torrans SESSION SUMMARY:
·	Ron Hodson of North Carolina and Larry Wilson of Tennessee reported interest in systems related to hybrid striped bass production. Both states reported intensive production, primarily with raceways not recirculating water. It was felt that there was also a need for developing intensive production systems for producing phase II hybrids close to the grow-out systems. One commercial system may be up and running this year. Poor survival during long transports may be reduced with systems for holding and hardening phase II hybrids prior to transport. Several participants reported losses of hybrid stripers due to a variety of intensive system failures.
·	Greg Clary, an extension economist with Texas A & M University reported a need for data on production costs and investments on different systems.
Three different raceway systems were discussed.
·	John Morrison, formerly of the Southeastern Fish Culture Lab in Marion discussed the use of raceways in Alabama to rear channel catfish to 1" prior to stocking out in ponds. He initially tested in-pond raceways similar to those being developed by Mike Masser at Auburn, but these were not very good for rearing fry because they were too hard to clean. He went to conventional above-ground raceways, and had success as long as the pond water source did not contain fish; if it did, columnaris was impossible to control. Following John's research success, two commercial units were put in production in 1995. They were stocked with 1000 fry/cu ft, with five water exchanges per hour, and fed a trout starter diet. Survival ranged from 90 to 100%, FCE's were 0.6-0.8:1, with fry reaching 1 1/4 " to 1 -" in three weeks with final density of 1 - pounds/cu ft. Both producers planned to expand their facilities this year.
·	Mike Masser discussed in-pond or floating raceways that he is developing at Auburn University. This system uses air-lift pumps to move low head water through the raceways at 12-15 exchanges per hour. He has produced 2800 pounds of catfish in raceways 16' X 4' X 3'. He feels he has reached nearly the maximum potential flow through the airlifts; a 1-hp blower can power 27 airlift tubes (9 per raceway) with a flow of 50-60 GPM per tube. He has stocked from 9 to 16/cu ft with no apparent effect on growth rates. Tilapia do well in these systems but channel X Blue hybrids apparently do not. He is also developing solids collectors for use with these raceways, and may experiment with wetlands for effluent clean-up.
·	Chris Hyde reported on a commercial producer in north Alabama who used one of these raceways, and likes them for holding catfish for his small processor. Market-sized catfish can be brought in from a pond and stocked in an in-pond raceway and will come on feed in a day or so.
·	John Collier of Clemson University has developed a pond partition system. A 2-HP hydraulically-powered, low-speed paddlewheel moves 13000 GPM of water through two parallel concrete raceways. Water then moves through a 1/3-acre, 3'-deep baffled pond before returning to the raceways. Nine replicate units have been built. Last year the systems were stocked with an equivalent of 6000 catfish/acre; this year stocking rates will be doubled and tilapia will be added to the system. Various water quality parameters are continuously monitored, with paddlewheel speed and aeration adjusted accordingly. Water flow through the raceways can be suspended while the fish are treated in the raceways or, as happened last year, the pond is treated for toxic algae.

March 18-20, 1995 Auburn University Attendees: Not available Facilitator: Andy Lazur SESSION SUMMARY: ALABAMA
·	Mike Masser reported on research with floating raceway production systems for catfish production. Yields of over 500 Ibs/m3 have been attained with a feed conversion of 1.5. Work with the raceway system including further evaluation of waste collection is continuing.
·	Len Lovshin discussed result on a pond/tank recirculating catfish production system using a low head oxygenation device (LHO). Preliminary results showed that although fish production and water quality were promising, the costs of the system were noncompetitive with pond production.
FLORIDA
·	Andy Lazur reported on a pond/plastic lined, earthen raceway recirculating system with oxygen supplementation with a LHO for the production of catfish and hybrid bass. The study showed that the system as designed was biologically, but not economically feasible. Andy mentioned that Frank Chapman Is currently evaluating a solar heating demonstration project incorporating a recirculating tank and vegetable production unit. Year one of a golden shiner/catfish rotation project showed good golden shiner production from May to October, but the production of small (1/2 lb.) catfish from October to April was minimal due to an outbreak of POD.
LOUISIANA
·	Jimmy Avery discussed Ron Malone's continued efforts in bead filter research and tilapia production. One project involves use of waste heat from a vinegar processing facility. Another project involves the filtration studies for red drum culture. In addition, work with biofiltration in alligator systems to reduce ammonia waste is being conducted.
NORTH CAROLINA
·	Jeff Hinshaw discussed Tom Losordo's studies on a new Norwegian biofiltration system for tilapia and hybrid bass. Jeff reported on efforts to incorporate water reuse and filtration in trout raceway systems. Studies with net-pen trout production in lakes is encouraging with good fish production and economic return. Studies with salmon and yellow perch are planned in near future.
SOUTH CAROLINA
·	Tom Schwedler reported on studies on high density catfish production in cages with yields of 10 lbs./ft3. In addition, he discussed the partitioned aquaculture system that incorporates raceways with catfish, settling basins, low energy water circulation and algal removing system. Fish production results showed rapid growth with a feed conversion of 1.4.
TEXAS
·	Joe Lock reported on continued studies with red drum culture. The cold water appears to be a limiting factor. Ponds with black plastic covered corners to allow for heat retention are presently being evaluated. He discussed a largemouth bass double cropping system involving production of bass fingerlings followed by pond draining and tilapia or catfish growout.
Future Needs. Two major topics were identified as essential to more completely evaluate alternative culture systems. These include studies involving the environmental impact of alternative systems, particularly net-pens which are not as common. Secondly, complete information on the economic considerations of all of these systems is lacking and is critical for further development.

March 13-15, 1994 Texas A&M University Attendees: Approximately 30 participants were present representing twelve institutions. Facilitator: Michael Masser SESSION SUMMARY:
·	Clemson University reported on experiments on combined stocking or phasing in cages and open-ponds to increase overall production and maintain high feed ingrates. Two different protein levels were evaluated within this system with interesting results. Clemson also reported on a partition production system where fish are partitioned in raceways and algae (in other raceways) fix carbon at rates three or four times higher than in traditional ponds.
·	Kentucky State University reported on on-farm demonstrations of low-management techniques for producing channel catfish. The technique utilizes equation feeding but maintains low levels of total feed input to produce 2000 pounds per acre in 175 day from 45 gram fingerlings with minimum water quality problems and management experience.
·	North Carolina State University reported on evaluations of both warmwater and coolwater recirculating systems for aquaculture. These systems do not appear to be commercially viable as of now for foodfish production. In the coolwater system, trout and Atlantic salmon have been rear but at costs above market value. The viability of producing advanced fingerling within these systems looks promising.
·	The University of Georgia reported on their involvement with training and assistance to Vocational Agriculture instructors developing aquaculture within their programs. Over 20 schools in Georgia are pursuing this curriculum.
·	Auburn University reported on the evaluation of different strains of channel catfish for cage culture and polyculture of catfish and tilapia in cages. Different strains have varying production characteristics in cages as compared to ponds. The polyculture of tilapia with catfish increased catfish growth. Auburn also reported on the development of an In-pond Raceways system which allows the confinement of fish at high densities with good water quality characteristics and the collection of fish wastes for removal from the pond environment.
The alternative culture methods IEG set two priorities for future research:
·	developing economic data on alternative aquacultural systems, and
·	examining the economics of all aquacultural research.

		Alternative Culture Methods
		Economics
		Engineering
		Fish Health
		Genetics
		NCID
		Nutrition
		Potential Alternative Species
		Quality Assurance
		Shellfish
		Water Quality
		Yield Verification

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