The research was conducted at 2 reef locations off the coast of Sudan. Shark populations are of concern in this region as there have been reports of illegal fishing of sharks around the Sudanese coast. The authors also comment on a lack of control over Sudanese shark fisheries.
The researchers used stationary underwater cameras to video shark activity during the day, and laser pointers to infer the total length of the sharks filmed. By gathering data in this manner, the team were able to compile information regarding species, total length, sex, ecology and behaviour of pelagic and reef associated sharks in this region. In total 6 species were recorded from the reefs: common thresher shark (Alopias vulpinus), scalloped hammerhead (Sphyrna lewini), whitetip reef shark (Triaenodon obesus), grey reef shark (Carcharhinus amblyrhynchos) and tiger shark (Galeocerdo cuvier).
The equipment and methods used in this study are relatively inexpensive and non invasive to the marine life. The survey techniques were also suitable for the adverse conditions of the study sites - both sites exhibited strong currents and relatively deep thermoclines which some of the shark species remained beneath. The relative ease with which these methods can be employed could facilitate the monitoring of shark assemblages in remote areas and contribute to data gathering of shark assemblages which presently, may be quite data deficient. This, in turn, could lead to a greater enforcement of shark regulation in these areas.
Danilo Rezzolla, Ginevra Boldrocchi and Tiziano Storai. Evaluation of a low-cost, non-invasive survey technique to assess the relative abundance, diversity and behaviour of sharks on Sudanese reefs (Southern Red Sea) . Journal of the Marine Biological Association of the United Kingdom, available on CJO2014. doi:10.1017/S0025315413001781.
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