Cross-Shelf Transport of Pink Shrimp Larvae: Interactions of Tidal Currents, Larval Vertical Migrations and Internal Tides
Vol. 345: 167–184, 2007 MARINE ECOLOGY PROGRESS SERIES Published September 13 doi: 10.3354/meps06916 Mar Ecol Prog Ser Cross-shelf transport of pink shrimp larvae: interactions of tidal currents, larval vertical migrations and internal tides Maria M. Criales1,*, Joan A. Browder2, Christopher N. K. Mooers1, Michael B. Robblee3, Hernando Cardenas1, Thomas L. Jackson2 1Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA 2NOAA Fisheries, Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, Florida 33149, USA 3US Geological Survey, Center for Water and Restoration Studies, 3110 SW 9th Avenue, Ft Lauderdale, Florida 33315, USA ABSTRACT: Transport and behavior of pink shrimp Farfantepenaeus duorarum larvae were investi- gated on the southwestern Florida (SWF) shelf of the Gulf of Mexico between the Dry Tortugas spawning grounds and Florida Bay nursery grounds. Stratified plankton samples and hydrographic data were collected at 2 h intervals at 3 stations located on a cross-shelf transect. At the Marquesas station, midway between Dry Tortugas and Florida Bay, internal tides were recognized by anom- alously cool water, a shallow thermocline with strong density gradients, strong current shear, and a high concentration of pink shrimp larvae at the shallow thermocline. Low Richardson numbers occurred at the pycnocline depth, indicating vertical shear instability and possible turbulent transport from the lower to the upper layer where myses and postlarvae were concentrated. Analysis of verti- cally stratified plankton suggested that larvae perform vertical migrations and the specific behavior changes ontogenetically; protozoeae were found deeper than myses, and myses deeper than postlar- vae.
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