depends on the crab.

these freshwater mitten crabs are mostly farmed, its sustainability comes down to economics as mitten crabs technically are invasive to Taiwan (taiwan has its own native species of hairy crabs 毛蟹 so ecological damage is somewhat limited)

ocean crabs have size requirements to meet and there are harvest quotas throughout the year -- there are even times out of the year where females aren't sold

🤓

...and then theres imported seafood