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International Journal of Aquaculture 2012, Vol.2, No.6, 29-39
http://ija.sophiapublisher.com
29
Research Report Open Access
Characterization of Bioflocs in a No Water Exchange Super-intensive System for
the Production of Food Size Pacific White Shrimp
Litopenaeus vannamei
Joshua Haslun
1,2
, Eudes Correia
3
, Kevin Strychar
2
, Timothy Morris
3
, Tzachi Samocha
3
1. Michigan State University - 288 Farm Lane, East Lansing, MI 48824 USA
2. Annis Water Resources Institute, Grand Valley State University - 131 Lake Michigan Center, 740 W. Shoreline Drive, Muskegon, MI 49441 USA
3. AgriLife Research Mariculture Laboratory - 4301 Waldron Rd., Corpus Christi, TX 78418 USA
Corresponding authors email:
haslunjo@msu.edu;
Authors
International Journal of Aquaculture, 2012, Vol.2, No.6 doi: 10.5376/ija.2012.02.0006
Received: 30 Aug., 2012
Accepted: 07 Sep., 2012
Published: 08 Oct., 2012
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.
Preferred citation for this article:
Haslun et al., 2012, Characterization of Bioflocs in a No Water Exchange Super-intensive System for the Production of Food Size Pacific White Shrimp
Litopenaeus vannamei
, International Journal of Aquacultute, Vol.2, No.6 29-39 (doi: 10.5376/ija.2012. 02.0006)
Abstract
Zero exchange super-intensive recirculating aquaculture systems (RAS) represent an environmentally “friendly“ alternative to
traditional shrimp culture methods, however the susceptibility to pathogens typically increases as the density of cultured organisms
increases. The study describes a greenhouse-enclosed super-intensive RAS, utilizing culture water from a 62
-
day nursery trial, to
grow juvenile (0.99 g)
Litopenaeus vannamei
, Pacific White Shrimp, to market-size under high stocking density (450/m
3
). The study
evaluated the effects of foam fractionation and settling tank particulate control methods on water quality and microbial particulate
related flora in four 40 m
3
tanks with two replicates per control method under no water exchange. Microbial communities were
distinguished at the gram-stain level using flow cytometric fluorescent activated cell sorter (FACS) methods. Differentiation between
all other populations of organisms and particles between 1~20
μ
m was based upon autofluorescence and forward scatter (a size
indicative light parameter) using FACS. Analysis of variance indicated that the microbial communities associated with each
particulate control method did not deviate from one another significantly (p>0.05). Gram-positive bacteria were the dominate fraction
regardless of particulate control method (p<0.05). Six unique autofluorescence signals were consistently present within each RAS.
This study is a first step in using flow cytometry as a tool to document changes in microbial communities in no water exchange
super-intensive system for production of marketable shrimp. Shrimp yield and survival was high: 9.34~9.75 kg/m
3
and 94.5%~96.9%,
respectively. Further, the data suggest that the use of pre-conditioned water may help to prevent ammonia and nitrite overload and
decrease pathogenic organism prevalence.
Keywords
Super-intensive; Foam fractionation; Settling tank; Flow cytometry;
Litopenaeus vannamei
; Biofloc
Background
Over the last 30 years increases in epizootic diseases,
eutrophication of freshwater resources, and environmental
pollution have had a negative impact on the production
of commercially available Pacific White Shrimp
(
Litopenaeus vannamei
). Traditional production of
food shrimp typically utilized outdoor earthen ponds
with frequent water exchanges to maintain optimal
dissolved oxygen and water quality. These practices
increased the probability of release and introduction of
pathogen and eutrophication of coastal waters. The use
of zero exchange recirculating aquaculture systems
(RAS) is an alternative method of shrimp production. It
can minimize adverse environmental impacts and
improve biosecurity, defined as “the sum of all
procedures in place to protect living organisms from
contracting, carrying, and spreading diseases and other
non-desirable health conditions” (Moss et al., 1998).
Significant reduction in released nutrient-rich water
allows the system to be operated with native or exotic
species with minimal risk of escapement into receiving
waters while simultaneously decreasing the probability
of disease introduction from water exchange (Moss,
2002). Although zero exchange systems represent an
environmentally friendly form of shrimp production,
the associated cost is difficult to offset unless
super-intensive practices are used (Balasubramanian
and Ravachandran, 2004; Stokes et al., 2009; Wasielesky
Jr. et al., 2006). These practices decrease the probability of
pathogen introduction, increase biosecurity while
producing cost-effective margins of biomass production
(Browdy and Moss, 2005; Wasielesky Jr. et al., 2006)
demonstrated that zero exchange super-intensive methods
enclosed in greenhouse structures decrease these risks