The St. Johns River Management District (SJRWMD) has contracted with Florida Tech scientists for a two-year, $300,000 project to obtain additional data regarding the fish larvae and eggs (ichthyoplankton) that inhabit the St. Johns River. The study is part of a comprehensive SJRWMD effort to address public concern regarding the cumulative impact of possible water withdrawals from the St. Johns River.
One measure of the river’s current and future health is its role as a nursery habitat for fishes. Jonathan Shenker, Ph.D., Florida Tech associate professor of biological sciences, was funded by the grant to study the ichthyoplankton at six locations along the river. Shenker has 30 years of experience in fisheries and ichthyoplankton research in habitats in the United States and Caribbean.
He has put together a team of eight graduate and undergraduate researchers. Already at work since February, they’re sampling river water with plankton nets, preserving eggs and larvae, and identifying, counting and measuring fish in the laboratory. These data will enable the researchers to develop predictions on the vulnerability of ichthyoplankton to water withdrawals or environmental changes, and ultimately, project the effects of these losses on juvenile and adult abundance.
The researchers are targeting specific East Central Florida locations along the St. Johns River. These are the St. Johns along State Road 50 in west Titusville; three areas near Lake Monroe in Seminole County; riverine habitats near State Road 44 in Volusia County; and, closest to Florida Tech, Lake Poinsett in Titusville.
“We’ll get baseline data over an almost-two-year time span,” said Shenker. “Ultimately we will use this information to model what would occur if specific volumes of water were extracted and identify the boundaries of the environmental conditions we associate with significant environmental effects.” The final report is due Dec. 31, 2009.
“I have no preconceived notions about the magnitude of any impacts,” said Shenker. “We’ll have to see what the data show. In addition to the impact assessment, this work will give us insight into many of the fishery species that live in the St. Johns. It’s a fantastic biological experiment.”