Sweep,
I urge you to chat with any marine biologist not affiliated with the greens, (i sound like a skeptic i know!) The spillover effect does not work full stop. Larger fish will not move to another area once thet have out grown their current one, they will remain where the food source is. An effective management scheme would be to close fishing in strugling areas, and have moving sactuary zones, or seasonal zones, similar to canada's management of the salmon fishery.
Also, in regards to the tourism effects, i for one will never travel to seal rocks again, it has nothing for me when i can travel further to the solitary islands Marine park, Coffs Harbour. A well managed MP. Seal rocks is closed to all fishing, as is Sawtooth, the entire headland, is unfishable. The town will go bust, you can not argue against this. And comparing the $$$'s from the Great Barrier Reef MP, all this advises is how much is at stake, the Queensland State Government is currently being Sued for $90,000,000 in lost revenue due to the park. This is solely from fishing tourism $$$'s. Check the link i posted earlier in this thread, its a study/survey of fishing/toursim $'s spent in batemens bay/narooma and port stephens.
I'll check back later and hopefully i can learn to spell once i've had a coffee or two, 8:30 on a monday is to earloy for me.