Ph.D. student Ashley Dawdy published in the ‘Fish Movement’ special issue of Environmental Biology of Fishes

Announcing a recent publication in the ‘Fish Movement’ special issue of Environmental Biology of Fishes from Ashley Dawdy, a current PhD student of the Grubbs lab. This publication is a result of Ashley’s undergraduate Honors in the Major thesis, completed here at FSU with former Grubbs lab students Dr. Cheston Peterson and Dr. Bryan Keller!

Dawdy et al used active acoustic tracking to investigate the drivers of space use and movement behavior in bonnetheads and bull sharks in Apalachicola Bay. Active tracking is a type of acoustic telemetry, in which you implant an acoustic tag in a fish and then physically follow it around by boat. The tag transmits pings (sounds) into the water column, which can then be picked up by a mobile receiver we have on board, allowing us to keep up with how far the animal is from the boat and which direction it is moving. This type of tracking is laborious, but it provides very fine-scale behavioral data. Animals in this study were tracked for up to 52 hours each!
Analysis showed that tidal and diel periods had varying effects on shark movement, with animals traveling at increased rates of movement during crepuscular periods (dawn and dusk). Movement behaviors observed in bonnetheads provide an explanation for their high by catch rates in the Gulf of Mexico shrimp trawl fishery. Movement behavior in both species is likely driven by a combination of optimal foraging strategies, predator avoidance, and abiotic factors. To learn more about the space use and movements of these sharks, check out the abstract here:

This project was funded by the Helen Louise Lee Undergraduate Research Award funded by Dr. Jim Lee, the Bess H. Ward Thesis Award funded by the Florida State University Department of Biological Science, and the The FSUCML Board of Trustees Graduate Student Research Fund. Click below the gallery below to see pictures of her research process.