Project Personnel: Tom McElroy, 305.348.4032, mcelroyt@fiu.edu; Tim Collins, 305.348.2200, collinst@fiu.edu

Supporting Organizations: NPS and FFWCC provide permits

Associated / Linked Projects: ATLSS (USGS-BRD program); RECOVER

Overview & Status: In modeling the dynamics of aquatic animal populations in southern Florida wetlands, the dispersal distances, rates of movements, and timing of movement are important but poorly understood. The small size of the wetland animals precludes the use of standard marking techniques for studying movement, and the large, open system of these wetlands makes recapturing marked animals improbable. Genetic markers, used to determine population structure, offer an indirect way of assessing the degree of movement and mixing in these populations, and the landscape-level patterns of animal movement. In a series of studies in this multi-year project, our objectives are to identify population structure of selected aquatic species in the Everglades and to estimate migration rate from genetic data on gene flow for incorporation in the ATLSS model. Data from studies on whether levee and canal systems act as barriers to dispersal of aquatic animals in the Everglades are applicable to the RECOVER. We are also using genetic techniques to learn if populations of introduced Asian Swamp Eels have the same source of origin. We have also begun a radio-tracking feasibility study to examine dispersal and habitat use by large fishes. Results have management implications for restoration, modeling, and control of introduced species.

Needs & Products: Products: 1) Trexler, J. et al. 1999. Metapopulations or patchy populations: Population structure of three species of aquatic animals from the Everglades. Review manuscript; 2) Trexler, J. C., W. F. Loftus, F. Jordan, J. H. Chick, K. L. Kandl, T. C. McElroy, and O. L. Bass, Jr. 2001. Ecological scale and its implications for freshwater fishes in the Florida Everglades. Pages 153-181 IN J. W. Porter and K. G. Porter (Editors). The Everglades, Florida Bay, and coral reefs of the Florida Keys: an ecosystem sourcebook. CRC Press, Boca Raton, Florida; 3) Collins et al., 2002. Genetic characterization of Asian Swamp Eels in the United States. Conservation Biology; 4) Several posters and presentations at scientific meetings. We intend to increase the level of radio tracking, now that it is shown to be feasible, to increase data about habitat use and movement patterns with season.

Application to Everglades Restoration: Data add information to the ATLSS models about dispersal distances, the effects of levees as barriers to movement, and the use of marsh and canal habitats by fishes. Population structure can be used as an indicator of connectivity used in RECOVER. Results have management implications for restoration, modeling, and control of introduced species.