One of main subplots of the new-ish movie Mud, starring Matthew McCaughey, involves a poor Mississippi River Delta teen, Ellis, who helps his father catch catfish and sell clear plastic bags of the cleaned fish out of the back of the family's beaten pickup truck.

That entrepreneurial food startup was all the income Ellis's family appeared to have.

While I suspect Ellis's family business probably skirted the laws of Arkansas, where the family's riverbank home was located (and where I've done most of my best catfish eating), I know with great certainty that their simple local enterprise would run afoul downriver in Mississippi, thanks to the latter's newly amended Catfish Marketing Law.

The Mississippi law, which updates a 2008 law, requires every grocer and restaurant in the state to "provide the consumer with the country of origin and method of production of catfish" and, now, of other catfish-like fish.

While the 2008 law required groceries throughout the state to provide country-of-origin labeling for catfish alone, the new law expands the measure to include all catfish-like fish, which is mostly imported, at every "restaurant, cafeteria, lunch room, food stand, saloon, tavern, bar, lounge or other similar facility operated as an enterprise engaged in the business of selling food to the public."

The law expands the state's ability to require "any person that prepares, stores, handles or distributes catfish or fish for retail sale maintain a verifiable record-keeping audit trail."

The rules contain a host of menu labeling provisions that "shall be provided to the consumer on the menu of the food service establishment." They require those engaged in wholesale or in direct sales to consumers also to label their catfish.

In Mississippi, restaurant buyers are subject to the menu-labeling and record-keeping laws. But sellers like Ellis and his dad (who also sold in the movie to restaurants) might be subject to the record-keeping provisions—if a restaurant can be required to keep records, then a smart restaurant would require those selling to the restaurant to do the same—and would probably be subject to the "retail sale" and "wholesale" labeling requirements.

Though the impact here is only hypothetical—Ellis is just a character in a movie, after all—the basis for the actual Catfish Marketing Law doesn't rest on very firm ground, either.

It's true that a small amount of imported catfish has raised food safety issues in recent years.

But while the state bills the rules under the familiar veil of helping consumers "make more informed decisions," most news reports on the catfish law (even those that simply repost the state agriculture department's press release announcing the new rules while claiming authorship) serve up headlines like "Country of origin labeling law aims at protecting local farmers."

If this sounds suspiciously like a protectionist measure, that's because it is. Reports on the 2008 rule made it clear the rule was also "designed to protect the domestic catfish industry from imports of catfish and similar fish[.]"

Though the law was intended to protect Delta residents like Ellis and his family from foreign competitors, its unintended consequences will likely impose new costs for these same people in the form of greater liability, thousands of dollars in potential fines, and confusing or impossible record-keeping requirements.

While I believe Mississippi gets it wrong with the Catfish Marketing Law, that's not to say the state's food laws are all headed in the wrong direction. They're not.

Take the state's so-called "anti-Bloomberg bill." That law, passed earlier this year, is by my estimate the seventh in the country to bar local governments from banning or otherwise restricting consumer food choices in restaurants and groceries. (Ohio's ban was later overturned.)

The Mississippi measure also prohibits local governments from "designati[ng] food as healthy or unhealthy," offering a key bulwark against further potential government interference in the food choices of the state's residents.

Critics have mocked the state for passing the law, noting that Mississippi typically ranks near the bottom on U.S. reports on health and well-being. And they did so in a nasty, condescending manner I don't recall seeing in the case of the Ohio measure or those passed in other states.

The narrow view taken by critics of the anti-Bloomberg bill is that state legislators are hell-bent on making an unhealthy state even less healthy. But I suspect those same critics would cheer two other regulations adopted in recent years in the state— the lifting of sales taxes from farmers markets and passage of a cottage foods law—if they took time to note them.

Mark Twain once defended the catfish as "plenty good enough fish for anybody."

While Mississippi's Catfish Marketing Law puts up more red tape for small food entrepreneurs in the state, other recent laws paint the picture of a state exploring ways to loosen regulations for food sellers great and small alike. And that trend is plenty good.