What if it were for less nefarious reasons? Perhaps he's planning on shutting the entire area down from human access completely and letting some flora and fauna having a refuge area.
For the record, its not that great of a surf spot, but this is more about letting someone establish precedent and thus leading to more beach access rights (Malibu...) getting chipped away at slowly but surely.
It would be great if we had Hawaii's right-of-way laws...
And to the original poster - not sure why you were down voted for asking a question.
Alternatively, he's "defending himself against a power-hungry government determined to curtail his property rights"