A school of scalloped hammerhead sharks (Sphyrna lewini) near Malpelo Island in Colombia. (Image credit: Gerard Soury via Getty Images)
Hammerhead sharks have seemingly disappeared from two underwater mountains in the southwestern Gulf of California, and fishing is likely to blame, a new study has found.
Researchers looked at observations from divers over the last 50 years and found that scalloped hammerhead sharks (Sphyrna lewini) experienced a 97% decline at the El Bajo seamount and a 100% decline at the Las Animas seamount — both off the coast of Mexico — between the 1970s and 2010s.
Study lead author Kathryn Ayres, a research scientist at the nongovernmental organization Beneath The Waves, told Live Science in an email that she was “saddened but not surprised” by the results.
Scalloped hammerhead sharks are a critically endangered species threatened by fishing, according to the IUCN Red List of Threatened Species. The sharks are targeted for their large fins, which are used in shark fin soup, the authors noted. Researchers don’t know how many of these sharks are left globally.
“Scalloped hammerhead sharks, and most shark species in general,
