The local Coast Salish natives have been successfully farming oysters and other shellfish in the tidal zone for thousands of years. This actually improves the nearby environment by filtering the water, and sequesters carbon in the CaCO3 seashells. We could probably scale this up safely, if the DFO is still capable of regulating anything effectively.

We need to repair the DFO, the gutting of regulatory agencies is a root cause for many of these problems.

Sardines and other smaller fish are generally far more sustainable than the types of predator fish that humans have been pushed to prefer. There are also sustainable rates of fishing but our current economy doesn't work to incentivize this aside from the labels and NGOs approvals that go on certain seafood products.

Sustainable commercial open water fishing is completely acceptable to everyone, surely?