Diventures Magazine | English Edition August 2020 | Page 30

29 MARINE ECOLOGY The team used a combination of acoustic markers and cameras affixed to sharks to track 41 animals over a fouryear period. Gray reef sharks are known to congregate in the morning, with groups slowly gathering during the day until dispersing at night, a dynamic known as the "fission-fusion" cluster. The new study found that not only did sharks return to the same groups in the same locations, but were also made up of the same individuals. “Using a portion of the reef helps you find your friends, it can be difficult to maintain social bonds when you live in the ocean,” Papastamatio said, “but if sharks routinely return to the same spot on the reef, it helps them preserve the structure of their group.". This is not the first time that social media networks have been identified with sharks. Previous studies have shown that lemon sharks and blackheaded sharks, among others, form social groups. This behavior has also been observed in manta rays. However, the most important finding of the new study is the length of time that sharks keep their "friends." While group interactions may benefit feeding and reproductive behavior, it was observed that some sharks remained in the same pairs of friends for the duration of the four-year study, indicating that long-term bonding was likely. Diventures Magazine August 2020