https://en.wikipedia.org/wiki/Passenger_pigeon Passenger pigeons were hunted by Native Americans, but hunting intensified after the arrival of Europeans, particularly in the 19th century. Pigeon meat was commercialized as cheap food, resulting in hunting on a massive scale for many decades. There were several other factors contributing to the decline and subsequent extinction of the species, including shrinking of th…
Because of the laws of international waters etc it’s essentially impossible to police, short of aircraft/naval patrols being willing to fire on violators on sight. There is no legal basis to keep another nation from overfishing as long as it happens in international waters, and china largely just does what they want even in territorial waters. Unless you’re willing to start an international incident the best you can do is get one boat while the other 49 slip by with their haul.
We set up the laws of the sea basically on the same model as the United Nations. They’re there to keep the peace between international powers, not produce good governance.