Studying migration patterns of shortfin mako ( Isurus oxyrinchus) sharks in the south-west Pacific Ocean
Click Here to See Shortfin Mako Shark Tracks
Shortfin mako sharks are frequently targeted in recreational fisheries and captured incidentally in commercial pelagic tuna and swordfish fisheries around the world, including the south-west Pacific region. Research by Dr. S. Clarke and GHRI ( Clarke et al. 2006; Ecology Letters 9:1115-1126 ) has estimated that a median of about half a million mako sharks were utilized in the global shark fin trade as of the year 2000. Given the high fishing pressure on this species and declining population trends in parts of its range, the shortfin mako is listed as "Vulnerable" on the IUCN Red List of Threatened Species .
The status of the shortfin mako shark population in the south-west Pacific Ocean is uncertain. Tagging with conventional gamefish tags by New Zealand scientists has shown that New Zealand mako sharks disperse to tropical areas to the north and to Australia in the west. However these conventional tags tell us nothing about the timing of their movements, or the route they take. We need to understand the movement dynamics and stock structure of mako sharks in order to better determine the status of this species in the south-west Pacific. GHRI and the New Zealand National Institute of Water and Atmospheric Research (NIWA) have begun a collaborative tagging study which aims to track New Zealand mako sharks using electronic satellite-reporting tags. The remarkable track of a female shortfin mako shark (named Carol) can be seen by clicking on the link above.
Images © Scott Tindale