No, there is an increase in the seal population which is the sharks natural food source. People swim near seals and are easily mistaken by the sharks, a person on a boogie board or surfboard looks like a seal from below.
There are signs here on the west coast to avoid swimming near seals.
There are also changes in the water temps that are moving the seals to different areas following the fish schools they feed on, thus attracting the sharks to new areas.
The Marine Mammal Protection Act (1970's?), while of noble objective to protect whales from being killed indiscriminately, for better or worse also created complete protection for seals, whether or not it was necessary or appropriate to do so.
As a result, on the ocean side of lower Cape Cod
alone, from Chatham to Provincetown it is estimated that there are now somewhere between 35,000 -- 50,000 seals. It's no real surprise that sharks are now there in ever increasing numbers. Why wouldn't they be? It's a virtual "all you can eat buffet" there now for them, 24/7.
Each individual seal reportedly eats 10 or more pounds of fish per day; that might provide some insight into why the inshore marine fish stocks have been completely decimated in the areas where seals are abundant (and multiplying).
If you have ever been just "downwind" of a seal colony (...and yes, I have), the stench is simply indescribable.
My late beloved Dad told me that back in the day, fisherman (and anyone else) would get
paid (at the local town clerk office) a bounty for every individual nose of a dead seal delivered to the town offices. I seem to recall him saying that the "bounty" paid was a nickel or a dime, per nose. lt seems that things have changed a bit since then; now we
protect all seals despite the horrific ecological imbalance that has been unintentionally created by their complete protection.