Effect of partial harvesting strategies on Artemia biomass production in Vietnamese salt works

Abstract

The e¡ect of partial harvest strategies on the production of Artemia biomass was evaluated for 12 weeks under Vietnamese salt farm conditions. The initial stocking density was 100 nauplii L À 1 . After 3 weeks of inoculation, Artemia adults were partially harvested at intervals of 1, 3, 6 and 9 days starting with an initial quantity of 30 kg ha À 1 day À 1 at ¢rst harvest, and then the quantity of harvestable biomass was adjusted according to the standing stock present in the culture pond, combined with the time needed to harvest these quantities and with the weight of biomass harvested in each pond. The results showed that in most cases, the total densities were not significantly di¡erent among harvesting frequencies (P40.05). However, a relatively higher Artemia adult density and its standing stock were better maintained in the 3-day than in the 1-day interval, and were signi¢cantly higher compared with the other two harvesting frequencies. The total biomass yields were the highest (1587 kg ha À 1 ) in the 3-day harvesting interval, followed by 1-, 6-and 9-day harvesting interludes, corresponding to 1323, 1091 and 975 kg ha À 1 respectively. However, no statistical difference was observed between the 1-and the 3-day interval as well as between the 6-and the 9-day harvest schemes (P40.05). The results of this study suggest that partial harvest of Artemia biomass performed every 3 days appears to be an appropriate strategy to enhance biomass productivity.Values with di¡erent letters (a^c) in a row are signi¢cantly di¡erent (Po0.05). The numbers within parenthesis indicate the degree of freedom (d.f.) between groups and within groups respectively.

Yield and Economic Efficiency of Green Water in Combination with Supplemental Feeds forArtemiaProduction in Vietnamese Salt Ponds

“…This result corresponds to previous studies focusing on the production of Artemia cysts Anh and Sy 2012) and of Artemia biomass (Anh et al 2009(Anh et al , 2010.…”

“…Harvesting of Artemia biomass was based on the study of biomass harvest strategies by Anh et al (2010). A triangular scoop net (0.6 × 0.6 × 0.9 m, 1.2 mm mesh size) was deployed horizontally under the water surface at places where the Artemia population concentrated.…”

The long‐term changes in plankton composition: Is Bay Sivash transforming back into one of the world's largest habitats ofArtemiasp. (Crustacea, Anostraca)?

“…A decrease in cyst production is now observed due to global reduction in the habitats traditionally used to harvest Artemia cysts, due to climate changes and human intervention, and it is expected that this crisis will deepen (AghaKouchak et al, ; Asem, Mohebbi, & Ahmadi, ; Shadrin, Anufriieva, & Galagovets, ; Wurtsbaugh et al, ). Intensive cultivation and creation of new Artemia populations (by intentional introduction) in salt lakes (previously without Artemia ) are developing now (Anh, Van Hoa, Van Stappen, & Sorgeloos, ; Jia et al, ; Pacheco‐Vega, Cadena Roa, Ascencio, Rangel Davalos, & Rojas Contreras, ; Sultana et al, ; Tackaert & Sorgeloos, ), but this cannot contribute significantly to satisfy the required world demand on cysts. Another option to sharply increase the world's Artemia cyst harvest is the new natural habitats of Artemia spp.…”

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“…According to [32] , mentioned that in natural Artemia culture systems is important to make partial harvesting activities and not only final harvesting because intraspecific competition between different stages of this organism can be eliminated. These authors mentioned that is better to make adult biomass harvest every third day [33] , but it is important to make continuous nauplii inoculations in the culture system because this harvesting method did not allow that adult biomass can be reproduced, and contributed the nauplii supply to culture system naturally form. These authors mentioned that in natural biomass production in ponds only biomass harvest is possible in 3 to 4 weeks because adult biomass decreases considerably if nauplii inoculation is not made.…”