Harmful algal blooms (HABs) are a proliferation of algal or cyanobacterial colonies that can detrimentally affect and kill local fauna, and impact public health. The Indian River Lagoon (IRL), an estuary that spans 40 % of the Florida’s Atlantic coastline, is one of the most species diverse estuaries in the United States. In recent years, the IRL has experienced a variety of reoccurring HABs and these events are expected to continue until effective management strategies to minimize nutrient loading are applied. The IRL is an important bull shark nursery, but the impact of HABs on these animals is unknown. This project involves attaching an accelerometer/magnetometer package to juvenile bull sharks in the IRL to understand their behavioral response to HABs. It also complements an ongoing study by the Fisheries Ecology and Conservation Lab on the bioaccumulation of HAB toxins in elasmobranchs.

This project is funded by a Save Our Seas Foundation Small Grant.

A juvenile bull shark fitted with a bio-logging tag.  The tag is composed of a tri-axial accelerometer, magnetometer, pressure sensor, temperature sensor and a satellite transmitter which I use to locate and recover the device.

A pseudo-track of a juvenile bull shark’s movement. Pseudo-tracks are estimated using an animal’s direction and speed to update the previous time step position; a process known as dead-reckoning. Direction and speed are calculated from  magnetometer and accelerometer data respectively. This pseudo-track is colored by a measure of body movement, with warm colors representing more intense activity levels.