Alaska snow crab season canceled after disappearance of an estimated 1B crabs

Something similar happened to the cod fishing industry in Newfoundland and other parts of eastern Canada 30 years ago. The reason: overfishing, due in large part to technological advances. Here's what happened:

Canada and NAFO continued to overestimate the abundance of cod in the Atlantic Ocean and therefore continued to set dangerously high [Total Allowable Catches]. This was in large part due to the widespread practice of calculating cod populations from catch rates in the commercial fishery – if fishers filled their quotas with ease, then officials believed the stock size was at adequately high levels. However, fishing technology had become so efficient by the 1970s that commercial catch rates remained high even as the cod population dropped to dangerously low levels. Electronic tracking devices could find fish no matter how small their numbers and trawlers could harvest most species with relative ease. ...

Although overfishing in international waters did tremendous damage to northern cod, Canada also failed to maintain a sustainable fishery within its 200-mile limit. The government ignored warnings from inshore fishers and university scientists that cod stocks were in danger and chose to maintain quotas instead of scaling back the fishery, in large part to prevent economic losses and massive unemployment.

By the early 1990s, after decades of sustained intensive fishing from Canadian and international fleets, the northern cod stocks collapsed. The spawning biomass of northern cod had dropped by about 93 per cent in only 30 years – from 1.6 million tonnes in 1962 to between 72,000 and 110,000 tonnes in 1992. In July of that year, Canada imposed a moratorium on the catching of northern cod and ended an international industry that had endured for close to 500 years.

https://www.heritage.nf.ca/articles/economy/moratorium.php

They called off the season in 1992 and it never came back. A pillar of the local economy in the Maritimes was wrecked.

As for climate change and its impact on East Coast fishing, I've read that lobster fishing is no longer a viable industry in Long Island and it's declining in southern New England as waters get warmer and the lobsters permanently migrate north.

King Salmon fishing was shut down in much of Alaska this season as well. I was there during the time and driving through the Kenai Peninsula was much different than previous years. Normally, you'll see people lined up on the river all over the place.

Apparently the definition of "sustainable" comes from the United Nations, not NOAA: https://ocean.si.edu/conservation/fishing/sustainable-fishin...

They also disagree with you that they've never been sustainably fished.