Volume 55

Large Eddy, Small Eddy : Supplying Recruits tothe South Florida Ecosystem


Authors
Yeung, C.; Lamkin, J.; Jones, D.; Criales, M.; Richards, W.J.
Download PDF Open PDF in Browser

Other Information


Date: 2004


Pages: 1048


Event: Proceedings of the Fifty Fifth Annual Gulf and Caribbean Fisheries Institute


City: Xel Ha


Country: Mexico

Abstract

Where spawning and juvenile habitats are spatially disjoint in marine populations, connectivity is important to ensure sustainability. In the diverse subtropical marine ecosystem of South Florida, keystone species such as snappers (Lutjanus spp.), spiny lobster (Panulirus argus), and pink shrimp (Farfantespenaeus duorarum) use the shallow, estuarine Florida Bay for nursery. A principal spawning ground lies in the Dry Tortugas archipelagos some 150 km upstream of the Bay. A large, semi-pennanent cyclonic eddy frequently resides at the Dry Tortugas for periods of 1-3 months. Its evolution is modulated by the flow configuration of the Loop Corrent upstream in the Gulf of Mexico. Eventually, the Tortugas eddy moves eastward from the Dry Tortugas, propagating downstream in the form of a transient eddy towards the coastal waters offshore of Florida Bay. The eddy diminishes in dimensions with progress and ultimately disintegrates. The evolution of the Tortugas eddy provides a mechanism for the retention and nourishment of early life stages at the spawning source. The subsequent progress of the eddy downstream provides transport to the juvenile nursery. The association of eddy formation with the major boundary current in the Intra-Americas Seas also implies possible connections to Caribbean sources of recruits further upstream. To determine the significance of the eddy process to the supply of early life stages to the South Florida ecosystem, we followed the evolution of the Tortugas eddies using satellite SST and SSH imagery and sampled within and around these eddies on separate occasions. We expect to find high concentrations of early life stages along the edge of an eddy, to indicate retention; when an eddy passes offshore of the channels that connect coastal waters with Florida Bay, we expect to find high influx of early life stages through the channels, as evidence of onshore transport.

PDF Preview