The news article is from a local news story in Boston.
' "There is enough (of a problem found) to raise questions," Steve Murawski, chief of stock assessment for the National Marine Fisheries Service, told the Boston Herald.'
&
"He [Steve Murawski] said researchers have corrected the mistake and will check to what extent the data may have been skewed, using underwater cameras to film trawls done properly and those done with the faulty gear for a comparison. Murawski was scheduled to discuss the problem at a meeting of New England fishery managers in Providence, R.I., on Wednesday."

The "problem" is probably due more to incompetence rather than some deliberate effort to screw the local fisherman.
[My guess: These "researchers" probably *are* somewhat hostile towards fisherman and probably would want to screw the fisherman in general terms- if they hold the typical view of govt employee in similar situations- but incompetence is main factor.]
The normal result of govt incompetence is more dollars needed for training, and new equipment because this is the easiest solution, rather trying to replace any incompetence employees. And in this case this seems to be what the result is going to be.

The number of fishermans affected is not mentioned in acticle, but it can be inferred that it's a small number- pretty sure it's not all fisherman on the east coast of America. Generally speaking, if large numbers of people are affected then this is something reporters love to talk about.

Now the reason why this article is even in news is because of laws to restrict future fishing is a political issue. But if Steve Murawski, chief of stock assessment for the National Marine Fisheries Service is actually doing his job, opposed to bending to political pressure, then it's probably more "real" then merely "smoke".
[All of above is dependent on the reporter actually doing a fairly good job of reporting on this issue.]

Now, as far as a class action suit.
No court is going to allow a case based on govt incompetence, you would need to show neglect or better yet malice on the part of govt employees and senior management to have a chance. In this case the govt management [Steve Murawski], has responded and is doing something about, so this can be used as proof that you have absolutely no basis for your suit.
Now, if there was enough money involved and if you had some basis for a case, it might be worth the monetary risk for a lawyer to file a case and spend years of his life pursuing the issue.