Yes. If you're trying to protect representative ecosystems, larger is definitely better. I think there is pretty good consensus on that. We know marine systems are dynamic and they shift, so larger is better.
We set up protected areas for a number of reasons, for example, to have representative benchmarks to protect particular sites that we know are of importance, such as sponge reefs; to protect species at risk; etc. It depends on why you're setting these things up. If you're setting up large representative ecosystems, as is the prerogative for Canada, then large is important.