When you buy fish, make sure to buy from a sustainable source. Look for fish recommended by the Monterey Bay Seafood Watch organization. They provide lists of recommended seafood. Farmed fish can be a good source as long as the farming practices are sustainable. Wild fish are also fine, as long as the population of fish is not impacted due to the fishing or other parts of the ecosystem being impacted. For example, large-scale net fishing catches other sea life and kills them. The species is important, and so is where it comes from. For example, salmon is plentiful in Alaska, but not in California. You can also look at grocery store ratings like Whole Foods or buy from a store that holds these values.
This is important because if we don’t buy sustainable fish, we will consume their populations and no longer have those fish not only for our own food but also for a balanced ecosystem. Right now, bluefin tuna is on its way to becoming completely fished out. Consider that next time when you go for sushi. But even if you stop eating bluefin tuna, that doesn’t stop the person next to you from eating it, so we need government and world regulation to protect our food and wildlife systems.