Mako shark (Isurus oxyrinchus) gut clearance studies

PIER Research Staff:

Chugey Sepulveda, Ph.D.

Scott Aalbers, M.S.

Collaborative Researchers:

Diego Bernal, Ph.D., University of Massachusetts, Dartmouth

Nicholas Wegner, Scripps Institution of Oceanography

Using acoustic telemetry we are able to track the movements and stomach temperatures of makos that have been fed a ration of exact mass and an acoustic transmitter. The mako is subsequently re-fed at specific time intervals and eventually re-captured and gut contents measured.

OBJECTIVES

• Use acoustic telemetry and the voluntary ingestion of prey to estimate gastric evacuation rates in the regionally endothermic mako shark
• Investigate the effects of mako body size and visceral temperatures and how body size and or temperature influence gastric digestion rates
• Compare findings with those of ectothermic species

Tagged mako shark ready for release off of Southern California

A 24 hour acoustic track record illustrating dive patterns, stomach temperatures and natural feeding events.

Mako shark freely ingesting a prey item of known mass with an acoustic temperature depth transmitter hidden inside.