I wouldn't get too excited about making any $$ from catching tagged mackerel. When I was tagging sharks out West, a .02% recovery rate was considered a very good return ratio. Mackerel are highly pelagic, and are high on the food chain. So, IMO, there is more of a chance of the tags being eaten by a predator like a shark, tuna, porpoise, ETC., than an angler catching one. But that is just my unscientific opinion.......................With a bit of luck this may help with the gas next year.