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October 26, 2014
Camañor, Werner Jost
In 2011, the whitespot virus hit northeast Brazil and one of our farms. Survivals in our “low-density ponds” dropped from 90% to 10%, and, so far, they have not recovered. Even at temperatures above 28ºC, mortalities were high, which made us think we were dealing with an especially virulent strain of whitespot. Since we were working on a high-density, enclosed system long before the whitespot outbreak, we hoped that we could keep the virus out of that system, but we did not succeed. For over two years, 15 to 45 days after stocking, all our crops ended with total mortalities. We learned over time that it was impossible to keep the virus out. Using postlarvae from Aquatec, which never exposes its broodstock to the outside environment, we learned to live with the virus. You can probably call Aquatec’s postlarvae specific pathogen free (SPF). I’ll leave that interpretation up to Ana Caroline Guerrelhas, who owns and manages the hatchery.
In the last quarter of 2013, however, we had our first successful harvests in two years; survivals jumped from 0% to an average of 90%, even in the presence of the virus. From November 2013 to now, we increased our productivity from ten metric tons per hectare per crop to over 32 tons per hectare per crop. In our pilot project, we are working on biomasses of over 60 tons per hectare per crop. We call our technology “AquaScience”. It consists of 3,000-to-4,000-square-meter lined ponds, a central drain, shade net to prevent bird predation, zero exchange and reuse of the water. What is amazing is that we have no sludge production during the cycle. We recycle all our water for the next crop.
The reason I am writing about our system is to point out that maybe there will be a range of production systems in the future, dependent on factors like the environment, the economics of each country and exchange rates. Maybe different system will produce side by side. Maybe one system will prevail. We don’t yet know. It will be interesting to see how different concepts emerge and compete with each other.
About 15 to 20 years ago, strains of P. vannamei from Ecuador, Panama and El Salvador arrived in Brazil, and around seven years ago, the remains of Syaqua’s (Kentucky, USA) broodstock arrived in Brazil. Aquatec kept all the strains in a separate biosecure lab, and for the last 15 years, it has been working on a genetics program.
In response to a question on The Shrimp List about how he reused his water after a shrimp harvest, Werner Jost said:
We harvest the shrimps by machine through a sluice gate. At the end of the channel, we pump the water into a reservoir. This gives us time to prepare the harvested pond for the new cycle. After 2-3 days, we pump the water back to the pond. Salinity in the river is about 36 parts per thousand (ppt); we mix it with fresh water, and bring it down to 16-18 ppt. We treat the water to maintain the proper ionic balance for shrimps. If you have to start with new water, it takes 20 to 30 days to get the right composition and density of bioflocs for the postlarvae. When using reused our water, we can restock within ten days after harvest.
Information: Werner Jost, Camañor, Rua José Tomaz Ferreira Campos, 2155, Candelária - CEP 59066-160 Natal – RN, Brazil (phone +55-(84)-4008-0448, fax +55-(84)-4008-0449, email firstname.lastname@example.org, webpage http://www.camanor.com.br).
Source: The Shrimp List (a mailing list for shrimp farmers). Subject: Different Concepts. Werner Jost. October 25, 26 and 27, 2014.
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