Its hard to remember all the details from back then, but I believe he forced the tuna seiners to put in dolphin release panels at great expense and, at the time, it was a risky move to lower the panel without releasing the school or significant part ; this was a concession to the environmentalists.
The fleet pulled out and moved to the South Pacific - I assume the canneries went with them.
I was working for a guy that was building a state of the art seiner, but was forced to halt construction ; I lost my putative job as an alternate skipper as a result.
Later Reagan decided to settle the maritime boundaries with Canada on both coasts. The West coast lost prime (lucrative) bottom trawling grounds - and lots of jobs, on boats and canneries ; on the East coast, he ceded prime cod and lobster grounds - ruining both East coast industries. All of those areas, which had been worked since the beginning of the country by legions of fishermen, were no more. Stroke of the pen, law of the land ; input by affected people not needed or round filed.
Generally speaking, after these and other moves by later Presidents, the US Commercial Fishing Industry collapsed and is no longer a significant part of the US Balance of Trade. Same for mining farming and timber. This period was supposed to give rise to factory fishing boats with deck hands earning a wage, instead of a share, while NOAA sold off shore fishing rights to foreign fleets for the tax value of the fish harvested.
These events were part of the on going War on Natural Resource Harvesters begun under Noxious Nixon and which continues to this day.
I have all of the articles from then somewhere, in some closet, unless they got lost in some move.