Home Effects of Variable Flows on Water Chemistry Gradients and
Fish Communities in the Hillsborough River, Florida
The Hillsborough River is a freshwater tributary that runs to the Tampa Bay estuary. The river has been altered in several ways, including the construction of a dam in 1944 to provide a potable water supply to the city of Tampa. The portion of the river downstream of the dam and reservoir runs through the city of Tampa. Water release from the dam may affect salinity and dissolved oxygen levels between the dam and the estuary. Preliminary studies have also shown that changes in water quality may have negative effects on the diversity and abundance of fish populations below the dam.We will evaluate experimental water discharge levels below the dam and relate changes in water chemistry, fish diversity and abundance below the dam. Sampling will occur during periods of prolonged low flow, prolonged high flow and experimental pulses of flow. Our results will be used to develop ecological criteria for establishing minimum flows for the Hillsborough River downstream of the dam.