From: Francisco Javier Martinez Cordero <cordero@hawaii.edu>
To: AQUA-L@LISTSERV.ifmt.nf.ca
ECONOMICS OF ALGAL REPLACEMENTS
QUESTION:
As part of a bioeconomic analysis I will carry out on commercial shrimp hatcheries, I would require some cost estimations of algae production vs artificial substitutes.
Does anybody has had any cost effective results with algal replacements for penaeid shrimp? I am interested both in Penaeus vannamei and/or tiger shrimp. Even further: does anybody have some cost estimation (comparative) of live algae production vs artificial substitutes, and probably effects at different scales?
Francisco Javier Martinez Cordero
University of Hawaii-Manoa
Dept. of Agricultural & Resource Economics
3050 Maile Way
Gilmore Hall 112
Honolulu, HI 96822
USA
Fax: (808) 956-2811
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COMMENTS 1:
I have used live algae and various algal substitutes for over 16 years in the culture of penaeid shrimp and bivalves in South and Central America and Taiwan. From early on, I began to see a difference in the performance and cost of various live algae between bivalve and penaeid culture. Not only in the species which are cultured but in the day to day performance of the algae cultured under batch techniques. As far as penaeid culture is concerned, almost every hatchery I know sees a need for live algae nutritional supplementation or substitution. The early technology for algae substitutes for penaeid shrimp favored microencapsulation over micronized dry diets and manipulated yeasts. Some algae substitutes are more successful than others but virtually none of them are used commercially as a complete substitute. This is in part due to cost and in part due to performance. I have been using a new, comparatively low cost, spray-dried algae (Schizochytrium sp.aka AlgaMac-2000) for over a year now with very favorable results. I am able to completely substitute the AlgaMac-2000 for live algae after a single dose of live algae at Z-1 stage. I was able to achieve a 19% survival increase in P. monodon larvae production in Taiwan over traditional culture foods using AlgaMac-2000 at the 70% substitution level. I saw a 24% increase in survival over traditional culture methods for P. japonicus larvae culture at this same hatchery with an 80% AlgaMac-2000 substitution. The actual cost of the algae substitute was slightly higher (9.0%) than traditional Taiwanese feeds, but the increased survival more than compensated for this. I recently completed a study at the Centro de Investigaciones en Alimentacion y Desarollo (CIAD), Mazatlan, Mexico, using AlgaMac-2000, MicroMac-30 and Frippac CAR for larval P. vannamei rearing. This work will be presented at Tegucigalpa, Honduras, this month, but I will summarize it for you. Both CAR and MicroMac-30 (also microencapsulated diet) were fed at 6 mg/l/d. The AlgaMac-2000 was fed at 8 mg/l/d. Control received 50,000 cpm Chaetoceros sp. and 25,000 cpm T. suecica. All cultures received 5 Artemia/ml/day from M-1 to PL-1 and were stocked at 100 larvae/l. It was found that all artificial diets performed significantly better when a single dose of live algae (50,000 cpm Chaetoceros sp.) was administered at first feeding. The results showed survivals of 77% for control, 78% survival for the 75% CAR plus 25% AlgaMac-2000 diet, and 86% survival for the 75% MicroMac-30 plus 25% AlgaMac-2000 diet. The comparison of the AlgaMac-2000 diet fed at 8.0 mg/l/d as exclusive live algae replacement (after live algae at first feeding) was not statistically different from control (94% survival for control vs 97% survival for AlgaMac-2000). Survival apart, the cost
comparisons for MicroMac-30 and Frippac CAR (both fed at the same level of inclusion) show that the MicroMac-30 is less than half the cost of the CAR. (US$60.00/kg for the MicroMac-30 vs $143.20/kg for the Frippac CAR). Even though the AlgaMac-2000 was fed at 25% more inclusion than the CAR, the cost was still lower due to the difference in price/kg. (US$52.50 for AlgaMac-2000 vs $143.20/kg for the CAR).As for your questions regarding the cost of live algae production for aquaculture, the published data would have a wide variance due to the size of the hatcheries polled and the difference in densities and various algae species' dry weight. In general, the literature states the costs for live algae production to be somewhere in the range of $50.00/kg dry weight to $600.00/kg dry weight, with the majority falling in the $200.00/kg dry weight. The upper end of this range is to be found in facilities which use artificial light to culture algae. Fluorescent tubes can account for about 98% of the cost of culturing algae indoors. I hope this is of some help to you. Please let me know it you want copies of the papers I have summarized or any other information on this subject.
Phil Boeing
AquaTech Seafoods
1235 South Loop 4
Buda, TX 78610
USA
FAX 512-312-1258
Email: p.boeing@worldnet.att.net
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COMMENTS 2:
I agree with the labor costs aspects mentioned here, very high in Europe and some other countries. But Phil Boeings figures could easily be found in developing countries like Mexico. With outdoor mass culture techniques in most of the commercial shrimp hatcheries, labor is in these enterprises not the major cost for algae production. But still the performance of algae replacements is interesting for comparison as long as survival rates are kept in good levels.
Francisco Javier Martinez Cordero
University of Hawaii-Manoa
Dept. of Agricultural & Resource Economics
3050 Maile Way
Gilmore Hall 112
Honolulu, HI 96822
Fax: (808) 956-2811
Email: cordero@hawaii.edu
***************
COMMENTS 3:
I think your cost estimates are low. In fact the labor alone will exceed this figure in a small operation. For Isochrysis, 1 kg dry weight represents approximately 20,000 liters of harvest-density algae. It takes at least one man-hour to produce 200 liters of harvest density algae so this is 100 man-hours. That is a very conservative estimate remembering that you must take into account maintenance of subcultures, inoculation of flasks and carboys, cleaning of all glassware and culture containers, filtration of seawater, autoclaving or other sterilization process. If you also regularly clean up your algae with antibiotics this is an additional labor cost (as well as the supplies involved). In larger facilities, the labor cost is probably much less because the culture containers may hold thousands of gallons of algae, yet have to be cleaned no more often than a container holding only 40 gallons of algae. So, microalgae is at least 5 times as expensive to produce as you are saying, in a small facility. Nevertheless I have not found an acceptable substitute for feeding larval and juvenile bivalves.
Nancy Hadley
MRRI
PO Box 12559
Charleston SC 29422-2559
hadleyn@mrd.dnr.state.sc.us
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COMMENTS 4:
Probably you are right and there are people out there having huge costs in microalgae production. Nevertheless let me tell you that the opposite is also true, it is a question of paying attention to the algae and of course a scale subject. I get a reply for my AQUA-L mail telling that if the prices for algae are those I mentioned, they will quit their animal production and will start up a microalgae production facility.
Making some calculations on your figures, for 15-20 pg dry
weight / cel (T-ISO), I had reach to a cellular concentration at harvest on your cultures from 2.5-3.3 million cel/ml. Is that correct? I found it very low. Are you losing biomass on the harvest process? I can say that 95% efficiency is a good number.
Joao Navalho
Necton - Companhia Portuguesa de Culturas Marinhas
Unidade Piloto de Belamandil
8700 OLHAO - PORTUGAL
Tel/Fax: +351 89 703961
Email: necton@mail.telepac.pt
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COMMENTS 5:
We pay scrupulous attention to our algae which has something to do with our high costs because it takes a lot of labor to keep the algae this clean. I am operating on a small scale - producing approximately 300 liters of harvestable algae per day. My harvest density is minimum 5 millions cells/ml, often twice that, but I did my calculations based on million and I was pretty rough on the dry weight of T-Iso- I just called it 10^-11, whereas, as you note, it is probably about 1.7 times that. Anyway, this small scale runs up the labor costs. I estimate each 150 liter container at harvest represents a minimum of 1 hour of labor, probably closer to 2 hours. At one hour, the labor costs are $444/kg! We do not lose anything in the harvest as we do not centrifuge or concentrate the algae at all, we simply feed the algae and media directly to the bivalves.
Nancy Hadley
MRRI
PO Box 12559
Charleston SC 29422-2559
Email: hadleyn@mrd.dnr.state.sc.us>
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COMMENTS 6:
For small hatcheries operation I have figures that point to US$280-470 per kg dry weight microalgae. These prices are related to mono- specific cultures and include all the maintenance work with the algae cultures from stocks to ready to use live food.
Dealing with algae there is a point you can't forget, which is the sun light availability of the site. As photons are the major "nutrient" for algae grow, if you can get it for free you are saving a lot of money.
Other important aspect (I don't know if it is included in your analysis) is the choice of the hatchery manager. I don't think that so many hatcheries managers had made calculations for their real algae production costs. People are used to imagine the hatcheries with the microalgae division, can you imagine a hatchery without microalgae production?
Don't you forget also that microalgae are in the system not only for feed purposes. Culturing on "green water" reduces the ammonia levels in your system and gives to your animals a more "nature like" environment. This is used in sea bream culture.
With the environment pressures growing day by day it is necessary to think also about the waste treatment and water reuse. If you treat well your waste water you can grow microalgae on that.
I had heard a lot about ALGAMAC-2000, most of the comments saying that this is a good product. Nevertheless this is not an artificial substitute. On this subject my feeling is that nothing is like the natural. For what I know, ALGAMAC-2000 is based on heterotrophic growed microalgae. There is some work done on that, besides that particular one. I can remember about "Celsys Algae", a product based on heterotrophic growed Tetraselmis, which came
into the market some years ago and that is not available now.
Joao Navalho
Necton - Companhia Portuguesa de Culturas Marinhas
Unidade Piloto de Belamandil
8700 OLHAO - PORTUGAL
Tel/Fax: +351 89 703961
Email: necton@mail.telepac.pt
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