Project Summary Sheet

Project: Influence of Hydrology on Life-History Parameters of Common Freshwater Fishes from Southern Florida

Web Sites: www.fcsc.usgs.gov (see http://cars.er.usgs.gov/), sofia.usgs.gov

Location (Subregions & Counties): Central Everglades

Funding (Source): USGS Place-Based Studies

Principal Investigator(s): William F. Loftus, 305.242.7835, bill_loftus@usgs.gov; Leo Nico, 352. 378.8181, leo_nico@usgs,gov

Project Personnel: Joel Trexler, 305.348.1966, trexlerj@fiu.edu; Tim Connert, 305.348.4032, connertt@fiu.edu, Shawna Baker, 305-348-4032, shawnalove99@hotmail.com.

Supporting Organizations: Collecting permits — NPS and FFWCC. Mesocosm at ENP is used.

Associated / Linked Projects: ATLSS (USGS study); Everglades Restudy (RECOVER); Fish populations of South Florida Canals (USGS study).

Overview & Status: The objectives of this study are to establish age-size relationships for 11 species of fishes, construct life-tables, study reproductive phenology and fecundity, and apply the data to simulation models and to field data time-series. Work on this project began in late 1999 and is divided into large-fish and small-fish segments. We have finished the work with the large-bodied fishes from canal sites, from which we took otoliths from over 700 specimens, and examined gonads of >800 fishes for reproductive state. Otolith ageing was calibrated by checking otoliths from fishes injected with oxytetracycline (OTC) to place a mark on their hard tissues. We were unable to collect enough bullhead catfish specimens to obtain adequate data, but may pursue this species later. For the small fish segment, we have sorted collections of fishes from a long-hydroperiod and short-hydroperiod site. Those fishes were dissected to collect the tiny otoliths, and to perform examinations of the gonads. We have raised captive fishes for age validation in the mesocosm tanks. One portion of data for small livebearing fishes is presently being analyzed for a Master’s thesis; the second portion involving killifishes is underway, also as a Master’s Thesis. Lab/statistical analyses for the small fish work will continue for another year.

Needs & Products: Trimester reports, a Fact sheet, and a poster have been produced. The final report for the large fish segment is in review. We plan a series of 3-4 publications and theses that will describe the life-history characteristics of 11 Everglades fishes, representing new scientific information.