Evaluating remote setting techniques for oyster (Crassostrea virginica) seed production in Louisiana
Master of Science (MS)
Renewable Natural Resources
Research was conducted to implement remote setting technology for the commercial- scale production of oysters on alternative cultch material in Louisiana. Genetic research has created an enhanced oyster stock for commercial cultivation. Since the Louisiana oyster industry relies on natural seed production for product, they are unable to utilize these new advances and are never guaranteed a reliable source of oyster seed. Remote setting is one way of producing a consistent supply of genetically improved oysters. Cultch material for oyster settlement is a limiting resource. Several alternatives to clamshell have been explored. The objectives of this study are: (1) test larval setting success (penetration) using three cultch types in aerated and non-aerated treatments; (2) characterize triploid oyster seed growth and abundance among three cultch types on a commercial oyster lease; (3) characterize ploidy dilution of planted triploid oyster seed by natural diploids among three cultch types on an oyster lease; and (4) document the costs associated with seed bedding. Limestone had significantly less spat set than both whole and crushed oyster shell; spat set significantly less at bottom-depth and mid-depth in non-aerated compared to aerated treatments (objective 1). This shows the importance of aeration for spat settlement distribution among depths. Oyster growth was significantly less on limestone compared to both whole and crushed shell (objective 2). Spat on limestone were limited in two dimensional growing space. Of the fifty individuals sampled from each cultch type for percent triploidy, 2%, 4% and 8% were triploid for crushed shell, limestone and whole shell, respectively; all cultch types showed at least 92% diploid dilution (objective 3). These results are based on one site and season, therefore cannot be used to make conclusions about overall practicality for oyster production in Louisiana. The cost associated with seed bedding is $6.00 per barrel (objective 4). Whole oyster shell had significantly more initial spat set and growth than limestone. There was no significant difference in oyster abundance among all cultch types.
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Ippolito, Victoria D., "Evaluating remote setting techniques for oyster (Crassostrea virginica) seed production in Louisiana" (2010). LSU Master's Theses. 1032.