Principal Investigator: Lawrence Rozas
Co-Principal Investigators: Tom Minello, Rick Hart
Incorporating information about habitat-specific vital rates such as growth into stock assessments is a primary goal of the NOAA Habitat Assessment Improvement Plan. The management of brown shrimp Farfantepenaeus aztecus and white shrimp Litopenaeus setiferus would benefit by incorporating more realistic habitat-specific growth rates into stock assessments. Variation in the growth rate of juvenile stages of penaeid shrimps can have a significant effect on the size of adult stocks. Model simulations show that changes in shrimp growth rates may have more of an effect on stock size than fishing mortality.
The goal of our project is to estimate and compare growth rates for juvenile brown shrimp and juvenile white shrimp between vegetated marsh and shallow nonvegetated bottom habitats and incorporate this information into the new SS-3 assessment models for these species. Two different methods will be used to estimate growth rates: (1) a field mesocosm experiment and (2) a laboratory microcosm experiment. Both methods will be employed to measure growth rates during periods of peak estuarine abundance for each species. The field mesocosm experiments will be conducted in the Barataria Bay and Sabine Lake estuaries to examine between-estuary variation in shrimp growth rates, while the benthic cores used in the laboratory microcosm experiments will be collected only from the Sabine Lake estuary.
Our project will provide a range of growth rate estimates for juvenile brown shrimp and white shrimp. We will also examine variation in shrimp growth due to differences in habitat type that can be incorporated into the SS-3 model. Including these growth data into the SS-3 model will provide more accurate results for the prediction of adult abundance and provide managers with better information to make decisions about managing shrimp stocks.
