A new acoustic pH transmitter for studying the feeding habits of free-ranging sharks Article

Papastamatiou, YP, Meyer, CG, Holland, KN. (2007). A new acoustic pH transmitter for studying the feeding habits of free-ranging sharks . 20(4), 287-290. 10.1051/alr:2008003

cited authors

  • Papastamatiou, YP; Meyer, CG; Holland, KN

authors

abstract

  • Little is known about the feeding habits of large free ranging fish, due in large part to lack of an appropriate technique for quantifying feeding variables. A previous study demonstrated that changes in gastric pH can be used as a proxy for feeding events in free-ranging sharks. Here we describe the development of a new acoustic pH transmitter to remotely measure gastric pH in sharks in the field. The transmitter consists of a dual sensor (pH and temperature) continuous pinger, and was tested in captive adult blacktip reef sharks (Carcharhinus melanopterus). The transmitter was retained in the shark's stomach for between 5-12 days. The empty stomach had a low pH (1.6 ± 0.2) and feeding induced a rapid increase in gastric pH, which was clearly distinguishable from baseline levels. Meal size showed a significant linear relationship with the magnitude of the pH changes. Measurement accuracy of the pH transmitter ranged from 0.05-0.9, although resolution of the VR100 receiver that decoded the transmitter signal was 0.1 units. The pH transmitter can be used to determine when free-ranging sharks in the field are feeding and hence quantify feeding chronology, frequency and daily ration. © EDP Sciences, IFREMER, IRD 2008.

publication date

  • October 1, 2007

Digital Object Identifier (DOI)

start page

  • 287

end page

  • 290

volume

  • 20

issue

  • 4