SAO PAULO, Aug 6 (Reuters) - Brazil's seafood industry is sounding the alarm to pressure the federal government for immediate relief as it grapples with mounting fears of job losses and bankruptcies as a result of the 50% tariffs the U.S. imposed on most Brazilian exports on Wednesday.

The new levies made the future highly uncertain for Brazilian fishing companies, which sell close to $400 million worth of seafood to the U.S. a year, or about 70% of the sector's annual exports.