ナショナルジオグラフィックさんのインスタグラム写真 - (ナショナルジオグラフィックInstagram)「Photo by @thomaspeschak | Swimming in tandem, shark and surfer are portrayed in harmonious coexistence. Aliwal Shoal, near Durban in South Africa, is a popular dive site where visitors can swim with sharks in close quarters. The surfer is actually testing a prototype surfboard with a built‑in electronic shark deterrent. Here the deterrent is switched off, allowing the curious blacktip shark to check out the surfer. But when it was switched on, the shark immediately moved away, its sensitive electromagnetic organs having been overstimulated. Even without the use of experimental deterrents, the risk of shark bites is already incredibly low; in 2018 worldwide there were just 66 unprovoked bites, of which four were fatal. For more shark photographs follow @thomaspeschak.」1月23日 20時39分