Clinton Hittle
The pink shrimp is a species of special interest in each of the above studies because it has been chosen as an indicator species for use in restoration of south Florida estuaries. Empirical and experimental data developed in these studies will be used to support the development of a pink shrimp landscape simulation model and restoration performance measures.
U.S. Department of Agriculture - Natural Resources Conservation Service (NRCS) Department of the Interior - U.S. Geological Survey Department of Commerce - National Oceanic and Atmospheric Administration (NOAA) Environmental Protection Agency (EPA) Smithsonian Institution - National Museum of Natural History (NMNH)
40001 State Road 9336
Robblee, M. B.
Restrepo, V. R., Rice, J. K., Robblee, M. B., Zein-Eldin, A.
Moore, D.
Analysis of this data set will provide the pink shrimp simulation model with seasonal timing, size frequency data as well as abundance and size of juvenile pink shrimp in relation to bank, basin and near-key habitats seagrass cover. Specific objectives include:
1. Quantify density and size of juvenile pink shrimp in relation to bank, basin and near-key habitat in Johnson Key Basin, western Florida Bay. 2. Implement Braun Blanquet cover estimation as a means of associating pink shrimp abundance to seagrass and algal habitat. 3. Evaluate the existing benthic database in order to develop a monitoring protocol for assessing juvenile pink shrimp abundance and distribution in Florida Bay in relation to changes in salinity.
Using established methods nine stations (3 bank, 3 basin, 3 near-key habitat) in Johnson Key Basin will be sampled on a six-week interval for a total of 9 collections during FY2003. A one meter square throw-trap is used to quantitatively collect seagrass associated fish and invertebrates including the pink shrimp. Each throw-trap is swept three times to remove organisms. Four throw-trap samples are collected at each station as well as a suite of environmental and habitat variables. Previously habitat estimates have been made based on biomass estimates of seagrass and algae associated with throw-trap collections. Braun Blanquet is a categorical cover estimate technique currently used in seagrass monitoring programs in Florida Bay and the Florida Keys. In the laboratory samples will be sorted, all fish and shrimp (caridean and pink shrimp) will be identified to species and enumerated. Data will be stored in the Everglades National Park Oracle Database.
1. Quantify the seasonality and magnitude of postlarval pink shrimp immigration to Florida Bay. 2. Compare timing and magnitude of postlarval pink shrimp immigration from the Gulf of Mexico and the Atlantic Ocean. 3. Assess accessibility of inner Florida Bay to postlarval pink shrimp by comparing the timing and magnitude of Gulf of Mexico stations to Conchie Channel; of Atlantic Ocean stations to Panhandle Key Cut. 4. Assess sampling protocols by comparing postlarvae catch in relation to tidal phase and depth. 5. Participate in the development of a transport module for the pink shrimp simulation model.
Post larval pink shrimp sampling was initiated in January 2000. Channel nets (0.75 m2 opening, 1-mm mesh net, 500-micron mesh in the cod end) are used. The nets are attached to fixed moorings in the evening and samples are collected the following morning having passively collected postlarvae over night. The top of the channel net is set at .5 meter deep. At present paired channel nets sample six channels on two nights of the new moon; thus, four samples are obtained from each site each month for a total of 24. Pink shrimp postlarvae are sorted from the sample, identified, and preserved in 95% ethanol. The raw catch in each sample is standardized to density per 1,000 m3 of water filtered. Mean monthly density is calculated as the average over the two sampling nights. Densities are tested for normality and homogeneity of variance. Two experiments will be conducted to evaluate the current sampling methods. The present method of drifting the channel nets over night will be evaluated by sampling on a two-hour interval with the object of understanding when post larvae are most abundant. A second experiment will evaluate the relationship of depth and postlarval pink shrimp abundance by comparing catch in nets drifted at the surface, .5 meter and 1 meter. Experimental results will be used to aid in interpretation of catches or alternatively to modify sampling protocols.
1. Estimate volume transport in the six channels being sampled for postlarvae. 2. Construct rating curves at each station under a variety of tidal flow conditions in order to improve volume transport estimates. 3. Compare volume transport among the six stations in a comparison of postlarval immigration into Florida Bay. 4. Participate in the development of a transport module for the pink shrimp simulation model.
Measurements of flow, stage, and salinity will continue in FY 2003 in the six channels being sampled for post larvae. In collaboration with Dr. Joan Browder of NOAA these data will be applied to the construction of the larval transport module for the pink shrimp simulation module. Methods developed to date and in other studies will continue to be employed. Acoustic Doppler Velocity Meters (ADVM) have been installed at the instrumented sites and are used to measure continuous (15- minute) water velocity. A boat-mounted Acoustic Doppler Current Profiler (ADCP) is used to calculate total discharge along a transect of the channels during inspections. The ADCP also measures water depth, boat speed, and direction of boat movement using acoustic reflections from the streambed. Discharge and flow direction are both calculated from data collected with the ADCP. The mean velocity for the creek section is calculated by dividing the total discharge measured with the ADCP by the cross-sectional area corresponding to the water level at the time of the discharge measurement. The cross-sectional area is computed by using site-specific stage-area ratings. A velocity rating between the mean ADCP velocity and the in situ ADVM velocity is calculated by regression analysis. This rating equation is then used to calculate continous discharge using the velocity data. Stage measurements are made acoustically and through water pressure in the ADVM and Salinity instrumentation respectively. Stage is used to define the cross-sectional area over which flow measurements are made, and are used in the regression analysis between flow and stage. Salinity measured near the surface and bottom of each channel to quantify the vertical stratification present at each site, which could be detrimental to acoustic signals. Additionally, temperature is measured to monitor possible vertical temperature gradients that could be detrimental to acoustic signals and as a necessary parameter to calculate salinity from conductivity.
1. The CESI sponsored long-term study entitled 'Temporal and spatial variation in seagrass associated fish and invertebrates in Johnson Key Basin, western Florida Bay, with emphasis on the pink shrimp, Farfantepenaeus duorarum' will document long-term responses of the seagrass associated shrimp and fish community in Johnson Key Basin to environmental conditions (e.g. salinity) and changes in seagrass habitat
2. with Joan Browder the SFWMD sponsored study entitled 'Biscayne Bay Coastal and Nearshore Community Baseline Study to Develop Biological Performance Measures' will develop performance measures relating the fish and crustacean communities of southern Biscayne Bay to salinity and habitat
3 with Joan Browder, Maria Criales and Clinton Hittle the NOAA sponsored study entitled 'Immigration pathways of pink shrimp postlarvae into and within Florida Bay' will evaluate postlarval immigration (seasonal timing and abundance) to and into Florida Bay in relation to environmental conditions and habitat. The pink shrimp is a species of special interest in each of the above studies because it has been chosen as an indicator species for use in restoration of south Florida estuaries. Empirical and experimental data developed in these studies will be used to support the development of a pink shrimp landscape simulation model and restoration performance measures.
40001 State Road 9336
40001 State Road 9336
U.S. Department of the Interior, U.S. Geological Survey, Center for
Coastal Geology
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