Introducing: The State of Florida’s sawfish research group

The smalltooth sawfish, Pristis pectinata, is the only sawfish species residing in the United States. Its range is now limited to south Florida. Protection for the smalltooth sawfish in Florida began in 1992 and in 2003 it was listed under the U.S. Endangered Species Act. This species was never studied prior to population decline and range reduction, so research was badly needed to help put it on the road to recovery.

In southwest Florida, the Charlotte Harbor estuarine system, which includes the lower reaches of the Peace and Caloosahatchee rivers, is one of the largest remaining nursery areas for the species. Juvenile sawfish inhabit this area from birth to around 2.5 years old, ranging in size from about 0.7 to 2 m total length before moving into more marine waters. This estuarine system has been designated as one of two official critical habitat areas by the U.S. government, but sawfish are still affected by habitat modifications and development, especially in the highly altered Caloosahatchee River where flow is largely regulated by humans.

In 2004, with funding from the U.S. National Marine Fisheries Service, scientists at the Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute’s Charlotte Harbor Field Laboratory began fishery-independent research on the smalltooth sawfish in the Charlotte Harbor estuarine system. The research is focused in and near the Peace and Caloosahatchee rivers where several years of encounter data from the public indicated the presence of sawfish. The project, led by Dr. Gregg Poulakis, aims to monitor the long-term relative abundance of juveniles in both of these regions of the estuarine system while gaining a better understanding of smalltooth sawfish biology and ecology. The ongoing project is interdisciplinary and involves acoustic tagging to document movements, genetics to determine population health and relatedness, stable isotopes to examine diet, and more.

 

Dr. Poulakis with a tagged juvenile sawfish

Over the past decade, together with many collaborators, we have gained a considerable amount of knowledge on juvenile smalltooth sawfish in Florida. For example, juveniles double in length during their first year, often occur at specific locations called hotspots for months at a time, and respond to large increases in river flow by moving downriver. These results have helped influence management decisions to promote recovery and address many of the action items in the Smalltooth Sawfish Recovery Plan. As of this writing, the program has tagged almost 300 individuals, maintains two arrays of almost 100 acoustic receivers, and has published 13 scientific journal articles with its collaborators.

For more information, visit: http://research.MyFWC.com/sawfish

The Florida Fish and Wildlife Conservation Commission (FWC) Sawfish Research team