Start harvesting the marine mammals in number and the white sharks will leave.
Or, start packing the area with “migrants” and “asylum” seekers.
It is true that seal populations have been doing really well in the area. There’s seals in abundance all the way down to New York City.
Bring in a pack of orcas. There’s a pod on the west coast that arrives off San Clemente island to hunt seals every year. First order of business for the pod is to kill a GW Shark. All the Great Whites around the island have been satellite tagged and the researchers see a mass departure. Of course then you have Killer Whales ranging around your bathing areas and I’m not sure that’s an improvement.