Coastal Movements of Sand Tiger Sharks (Carcharias taurus) in the Northwest Atlantic as Determined by Acoustic and Satellite Telemetry

• Main Authors: Fox, Dewayne A., Wetherbee, Bradley M., Brown, Lori, Shivji, Mahmood S., Sulak, Kenneth, Moore, Johnny
• Format: Conference Object
• Language: unknown
• Published: NSUWorks 2009
• Subjects: Marine Biology; Oceanography and Atmospheric Sciences and Meteorology; Northwest Atlantic
• Online Access: https://nsuworks.nova.edu/occ_facpresentations/124

Prior to a recent harvest moratorium, sand tiger sharks (Carcharias taurus) were the focus of both directed and non-directed fisheries in the northwest Atlantic. Sand tigers occupy a high public profile due to their size and relative ease of public display. In contrast with many other large coastal sharks, limited information is available on the coastal movements of sand tigers including locations of overwintering areas. In 2008 we outfitted 13 sand tigers (1.4-3.3m FL) with acoustic (VEMCO Ltd. V-16-6H) and satellite (Microwave Telemetry Inc.) transmitters in Delaware Bay. Twelve of the thirteen acoustic transmitters were detected a total of 8,030 times prior to departing Delaware waters in September and October. Similarly, twelve of the satellite transmitters were detected within scheduled pop-off times (4-6 months post-deployment). Most sand tigers made relatively direct movements to overwintering areas in the Hatteras Bight Region, arriving within weeks of departing Delaware waters. An additional male sand tiger (1.09m FL) outfitted with an acoustic transmitter was detected off Cape Canaveral, FL in January-February, 2009 after departing Delaware Bay in September. Female sand tigers occupied significantly (p <.0001) warmer waters compared to males although occupied depths did not vary significantly (p=.1054). Although perceived as a relatively sluggish species, telemetered sand tigers were documented making rapid movements in the water column from surface waters to depths of 188m. Our results underscore the need for coast-wide approaches to recover sand tigers as this charismatic shark is particularly vulnerable to anthropogenic impacts.