Sharks are particularly susceptible to the effects of human exploitation because they have slow growth rates, a late age at maturity and low fecundity, traits which make them comparable to marine mammals in terms of vulnerability. Since fishing fleets expanded into the open ocean during the past 50 years oceanic pelagic sharks have been subject to intense exploitation that has raised concerns about broad declines in species abundance. Many tens of millions of individual sharks are harvested each year by high-seas fisheries. This is especially problematic since the exploitation of oceanic sharks remains largely unregulated. For the majority of shark species that make up over 90% of oceanic catches, no international or bilateral harvest limits have been imposed. Accordingly, there is a critical need and concern for improved management and conservation of oceanic sharks.
Management action for oceanic sharks is hampered by a paucity of high-quality data on total catches, landings, catch locations and the susceptibility of sharks to fisheries due to their highly migratory behaviour. Additionally, conflicting assessments of population trends of vulnerable species due to data limitations further complicates conservation strategies. Information is urgently needed on the habitat preferences, movements and migrations of oceanic sharks and the extent of overlap with commercial fisheries. For instance, stable or increasing catch per unit effort (CPUE) trends might be linked to changes in areas fished, which, if a consequence of overlap with important habitats of sharks, could mask real population declines that may already be occurring. However, a significant limitation affecting management of oceanic sharks is little knowledge of where, when and how fish and fishing vessels interact across their entire ranges. High-resolution monitoring of environment-fish-fishery interactions across whole population ranges is lacking, despite the potential of this approach to determine key species and habitats requiring conservation.
The Global Shark Tracking Project aims to:
(1) Build a global collaboration of shark researchers collecting satellite tracking data for multiple species.
(2) Map the global space use of pelagic sharks and identify movements, migrations and habitat preferences in relation to changing ocean environment.
(3) Quantify the spatial overlap between tracked sharks and satellite-tracked fishing vessels to inform management options.