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 |
