Campaigners have welcomed a ruling forcing the Scottish government to reveal how many seals are shot each year at individual salmon farms.
Ministers had argued fish farm staff, and their families, may receive threats if the information was released.
Now the Scottish Information Commissioner has said the government failed to comply with environmental information regulations.
Environmentalists described it as a "landmark victory".
Salmon producers are issued with licences which allow seals to be shot to protect fish stocks.
Campaigners have long argued detailed information about the number of seals being shot should be published, to enable consumers to make informed choices about whether or not to buy farmed salmon.
The Scottish Government had said that could put public safety at risk.
But the Information Commissioner did not accept that disclosing the information would represent a substantial threat to public safety.
Don Staniford of the Global Alliance Against Industrial Aquaculture said: "This is a landmark victory.
"Today's decisions are a shot in the arm for freedom of information and a shot across the bows of the bloody Scottish salmon farming industry.
"Now the public will be able to boycott salmon from lethal salmon farms.
"It is shameful that the Scottish salmon farming industry continues to kill seals and shocking that supermarkets still source seal-unfriendly farmed salmon."
The chief executive of the Scottish Salmon Producers' Organisation, Scott Landsburgh, said the number of seals shot by salmon farmers had declined dramatically in recent years.
He added: "We have championed deterrence techniques that are designed to keep seals away from our fish, and shooting is always a last resort."
A Scottish government spokeswoman said: "The Scottish Government has received Decisions 102/2015 and 103/2015 from the Scottish Information Commissioner, which relate to FOI requests by Global Alliance Against Industrial Aquaculture for information about numbers of seals shot and related correspondence and seal killing return forms for salmon farms for 2013 and 2014.
"We are currently considering their terms."
Animal rights campaigners have argued consumers ought to know what food producers are doing.
John Robins, from Save our Seals, told the BBC's Good Morning Scotland programme: "It's an environmental issue, its an animal welfare - an animal rights issue. It's also a consumer issue, the consumer has the right to know."
Mr Robins added: "All we want to do is compare the information we have with the information that the government gets.
"Then we can tell the public where the seals are being shot, which companies are doing the shooting and the public can decide whether or not they want to pay for bullets to shoot seals."