For the past 12 weeks, hundreds of leopard sharks have been washing up dead on the shores of the San Francisco Bay and researchers have no idea why.


Fish pathologist Dr. Mark Okihiro released findings that show a common pathogen found in three sharks examined so far, but that’s all anyone has to go on.

Sean Van Sommeran, executive director of the Pelagic Shark Research Foundation, “believes the source of the infections is the city’s use of tide gates near inland waterways.” 1


Leopard sharks come into shallow waterways to mate during the spring and summer.2 However, now that the sharks are dying their rotting and decaying bodies are being released back into the bay when the tide gates reopen and Van Sommeran fears they could be contaminating more animals.

Sources and References

  1. NBC Chicago, June 2, 2017.
  2. NBC Chicago, June 2, 2017.