Apologies for not making myself clear, my comment with regards to management of these resources was meant as opposed to indiscriminate pillaging. We will take things from the sea, but if some level of control or management is applied we can have a better chance of ensuring those "resources" are not completely wiped out.
I wouldn't argue that underwater hunting is necessary to manage the populations, obviously that is not the case, just that without some level of management those populations are at a greater risk.