ive gone to this area twice and fished once.
While snorkelling in akumal I definitely saw lots of fish so I am sure something would bite shore fishing off of the beach, however not much in the way of bigger game fish. I did see people fishing of the docks in Aventuras, just tossing a hunk of meat on a hook and catching a few fish.
Not sure if its in your budget of time and cost, but I did a guided trip out of the south end of cancun where my guide drove me up for an 8 hour trip around isla blanca and it was unbelievable. The guide put me on Tarpon, snapper, barracuda and permit, not to mention the scenery was unbelievable.
let me know if you want any information about my trip there.