Spatio-temporal behaviour of two oceanic pelagic predators: the blue shark and the shortfin mako shark

Ola Lundemo will present her PhD proposal, "Spatio-temporal behaviour of two oceanic pelagic predators:  the blue shark and the shortfin mako shark" at the Department of Biological Sciences seminar.

A comparative study of spatio-temporal behavior among two oceanic pelagic predators, Isurus oxyrinchus and Prionace glauca, off South Africa.

The blue shark (Prionace glauca) and the shortfin mako shark (Isurus oxyrinchus) are the two species of sharks most commonly caught as bycatch among the tuna and swordfish directed fishery in South Africa. Both species’ life history strategies infer relatively low resilience, and as such these two sharks are vulnerable to increases in fishing mortality. Blue sharks and shortfin mako sharks are listed in the IUCN Red List of Threatened Species as Near Threatened and Vulnerable, respectively. Both species are oceanic pelagic predators and undertake long migrations, often crossing ocean basins where they are unprotected by national fishery regulations. Satellite telemetry tracking studies significantly improves our knowledge of the movements of animals and is essential for cross-national conservation management. In this study, tracking data obtained from the ARGOS satellite system for individuals tagged for up to 90 days will be analyzed and superimposed with satellite composites for Sea Surface Temperature and Primary Production Index. The aim of this study is to pinpoint driving factors behind state-switching in movement patterns and investigate potential variations in states of fidelity and transit between the two species, as well as vertical utilization of the water column in relation to bathymetry and ecologically important habitats. The findings of this study are directly applicable to future management processes and in mitigating shark bycatches

Wed, 20 Sep 2017 - 13:00

Bio LT Room, HW Pearson Building, Upper Campus, UCT