As a marine ecologist, I do not mind the creation of artificial reefs but personally do not see them as necessarily advantageous to the local or regional ecology. I have the same feeling re: oil rigs. While they unquestionably attract certain species of marine life, they are often somewhat unnatural assemblages of species with many "missing ecological links."
Recently there has been a proposal in SoCal to add a $1 charge to each tank fill and dedicate the revenue to the State to develop artificial wrecks. I am decidedly opposed to this approach.
One reason? I do 250-350 dives a year so that would end up costing me $250-350 year. Pure self interest motivation there.
Other reason? I think if such a fee were ever seriously considered, it should go instead to protecting our natural reefs, mitigating the negative impacts on them, and implementing effective restoration methods to bring the systems back to a reasonable level of health.
An alternate proposed by others was an annual fee assessed to divers in the range of $30 to fund such projects for the natural reefs. Of course if such a fee were implemented for divers, similar fees scaled to the level of impact should also apply to fishers, personal and commercial watercraft, swimmers, jet skiers, surfers, freedivers, members of the five fathom club (just wanted to make sure you all were still reading this), etc.
As for the funding of artificial reefs, doesn't it make sense to have the Navy (= we taxpayers of course) pay the full expense of decommissioning and sinking these vessels. I understand they can't be recycled due to toxic components (please let me know if that is wrong).
Again, I am not opposed to artificial "reefs" per se and am glad there are those who are interested in working on such projects.