World Aquaculture December 2018

WWW.WA S.ORG • WORLD AQUACULTURE • DECEMBER 2018 43 ( C O N T I N U E D O N P A G E 4 4 ) that purchase fresh shrimp desire a product that has been raised locally without antibiotics and pesticides. Herbicides are available to limit the blooms of noxious algae but shrimp producers prefer non-chemical alternatives to resolve algal bloom problems due to the demands from their niche market customer base. As shrimp health is directly impacted by environmental conditions, resolution of mortality issues affecting these farms will likely require a pond ecosystem approach. The use of probiotics to confer health benefits to commercially produced aquaculture species, including shrimp, is an increasingly popular strategy (Boyd and Massaut 1999, Balcázar et al. 2006, Zhou et al. 2009, Silva et al. 2013, Aguilera-Rivera et al. 2014, Chumpol et al. 2017). Typical probiotics include those of bacterial origin or other single-celled organisms. Typically, the probiotic is offered in the feed or applied directly to water of the culture system (Moriarty 1998, Boyd and Massaut 1999, Ziaei-Nejad et al. 2006, Sapcharoen and Rengpipat 2013). Probiotics have various modes of action, including the ability to outcompete and inhibit growth of pathogenic gut bacteria and stimulation of the immune system. The reduction of organic matter in the pond environment is thought to limit substrate for pathogenic bacteria and limit regions of low oxygen that might adversely affect shrimp. Use of probiotic material designed for pond application can also reduce the incidence of blue-green algae. Bacillus sp. are commonly used in probiotic formulations due to their spore-forming ability. The advantage of using spore-forming bacteria is that the spores can be dried and stored for later application. Upon hydration, spores rapidly form live bacteria to populate their environment. Probiotics are commonly used in hatcheries and nurseries to limit disease incidence and promote growth but their effectiveness in grow-out ponds is not as well documented. Applied studies in commercial ponds often indicate conflicting results that support or reject the efficacy of probiotics. Probiotics tend to be specific for various pathogens and environments, so effectiveness may not be equal across farms with different pond soil types, cropping systems, production intensity, feed management and stocking regimes, water quality, culture water source and rearing environment. To investigate the efficacy of a probiotic to reduce shrimp mortality late in the production season, the Alabama Inland Shrimp Producers Association secured a grant from the U.S. Department of Agriculture Sustainable Agriculture Research and Education (SARE) program to carry out farm trials (Figs. 2 and 3) on three commercial shrimp farms in two states (Ala- bama and Florida). The objectives of these on-farm trials were to evaluate the effects of applying a com- mercially available probiotic on shrimp production, shrimp and pond Vibrio populations, shrimp health, and pond water quality with the end goal of determining whether probiotics might result in improved shrimp survival and production in southeastern US shrimp farms. Study Approach andMethods The probiotic product selected for the study was Sanolife® Pro-W (Fig. 4) (INVE Aquaculture, Salt Lake City, Utah, USA) that guaranteed a live bacterial concentration of 5×10 10 colony forming units per gram (CFU/g). While it is marketed for a wide range of applications in pond culture, this particular product was selected due to its reported ability to promote rapid decomposition of organic waste material, help control pathogenic bacteria such as Vibrio sp., reduce the development of blue-green algae and reduce ammonia concentration. Sanolife® Pro-W consists of a mixture of three Bacillus species that increase growth and survival in shrimp by direct consumption and also reduce organic loads in ponds by consuming organic matter. The probiotic was added by commercial farmer participants as a dried product once per week to production ponds at 200 g/ha per meter of water depth according to product LEFT, FIGURE 3. Inland low-salinity shrimp pond in the study at Forkland Springs farm, Boligee, Alabama. MIDDLE, FIGURE 4. The probiotic used for the study was Sanolife® Pro-W. RIGHT, FIGURE 5. Post-larval shrimp were acclimated to pond water conditions before stocking ponds. The vast majority of mortality issues reported by commercial shrimp producers have occurred late in the production season, often in conjunction with heavy blooms of certain species of blue green algae. As shrimp health is directly impacted by environmental conditions, resolution of mortality issues affecting these farms will likely require a pond ecosystem approach. Shrimp producers prefer non- chemical alternatives to resolve algal bloom problems due to the demands from their niche market customer base. On-farm trials were implemented to evaluate the effects of applying a commercially available probiotic with the end goal of determining whether probiotics might result in improved shrimp survival and production in southeastern US shrimp farms.