Abstract

The inland food shrimp industry and coastal bait-shrimp industry are both promising new aquaculture industries in Alabama. West Alabama has an abundance of low salinity artesian groundwater that is not suitable for traditional agriculture. This low salinity well water (LSWW) has been used for decades to culture channel catfish, and more recently, marine shrimp. The coastal bait-shrimp industry also has room for growth, due to the increased population in Alabama coastal regions and a reduced supply of native bait shrimp for recreational anglers. The development of these industries, however, are faced with similar problems, mainly the lack of information pertaining to salinity and temperature interactions in post-larval and juvenile stages of production.

Last year west Alabama farmers utilizing inland LSWW to produce shrimp reported poor survivals and lower production, presumably due to cold fronts that occurred as shrimp were being stocked. Lower salinities and suboptimal ionic ratios further complicate the problem. Similar problems have been reported by the coastal bait shrimp industry. Both salinity and temperature can have direct effects on several physiological responses in shrimp, including metabolism, survival, growth, and osmotic/ionic regulation.

Research outlined in this proposal is targeted at addressing salinity and temperature interactions in post-larval and juvenile native and non-native shrimp. The methodologies outlined are designed to address problems experienced by inland low salinity shrimp farmers as well as well as future coastal bait shrimp producers. As such, research will be carried out at two separate locations with native and non-native shrimp species. Facilities at the E.W. Shell Fisheries Research Station in Auburn, Alabama, will be utilized to address salinity and temperature interactions in post-larval and juvenile Pacific white shrimp, the species of choice for culture in LSWW of west Alabama. On the other hand, the Claude Peteet Mariculture Center in Gulf Shores, Alabama, will serve as the study site for native shrimp.

The objectives of this proposed research are four-fold. First, we will provide west Alabama shrimp farmers with much needed information pertaining to salinity and temperature tolerance of post-larval and early juvenile stage shrimp in order to make stocking recommendation that will increase survival, growth, and thus production of inland low salinity farms. Secondly, we will develop much needed information pertaining to temperature and salinity tolerances of post-larval and juvenile stages of native shrimp to facilitate the protocols for bait shrimp producers. Thirdly, we will determine growth rates and survival for juvenile native shrimp at various salinities and temperatures. Finally, we will demonstrate the production potential and determine growth rates of native shrimp under intensive culture conditions under two brackish water conditions.

We hypothesize that a complex relationship between salinity and temperature which is further compounded by suboptimal ionic ratios in shrimp reared in inland LSWW. A systematic approach involving growth trials at a range of salinity and temperature regimes is the best method to provide farmers with answers for both native and non-native shrimp.

Objectives

1) Provide west Alabama shrimp farmers with much needed information pertaining to salinity and temperature tolerance of post-larval and early juvenile stage shrimp in order to increase survival, growth, and thus production of inland low salinity farms. 2) Provide the coastal bait shrimp industry with much needed information pertaining to temperature and salinity tolerances of post-larval and early stage juvenile shrimp. 3) Determine growth rates and survival for juvenile native shrimp at various salinities and temperatures.

Methodology

A series of growth trials will be conducted with Pacific white shrimp and brown shrimp to determine the interaction of salinity and temperature.  Research with white shrimp will be conducted at the E.W. Shell Fisheries Research Station in Auburn, Alabama and will evaluate post-larval and juvenile growth and survival at a combination of temperature and salinity (Na:K ratio) regimes commonly found during the early production cycle in low salinity west Alabama waters. Research with brown shrimp will be conducted at the Claude Peteet Mariculture Center in Gulf Shores, Alabama and will also evaluate post-larval and juvenile growth and survival at a combination of temperature and salinity regimes commonly found during the early production cycle along the coast. In addition, a six large 35 m3 circular tanks will be utilized to produce bait shrimp at two test salinities and serve as a demonstration system for extension and outreach.

Rationale

In Alabama, both the inland shrimp industry and the coastal bait shrimp industry lack information pertaining to salinity and temperature interactions in post-larval and early juvenile life stages.  The lack of information has lead to reduced survival, growth, and overall production, thus severely reducing profits for Alabama farmers.  While both the inland shrimp industry and coastal bait shrimp industry in Alabama have plenty of potential for growth, data concerning the interaction of salinity and temperature on early life stages is a barrier to development of the industry.  Consequently, the objectives of this research are targeted at providing data to local farmers in order to increase production and assist with the development of these exciting new industries.