|Surfing iguanas? We got those!|
More important (from the perspective of selfish humans), MPAs can produce enough surplus to sustain species in non-protected areas that would otherwise be wiped out (read about MPAs in Indonesia for a recent effort or the extinction of the passenger pigeon for an example of our failures).
Bottom Line: We need MPAs as insurance against our greed and ignorance. Set aside "no go zones" to let nature nurture the ecosystems that make life possible -- and worth living.
* Ecuador does a decent job, given its poverty
** For a sad view of how humans fail at this, consider dog breeding