US shrimpers out of Florida bach in the 70s used formaldehyde sprinkled on their catch because their holds were not insulated and ice was too expensive.
The main problem today is that US Gulf shrimp quotas are too low ( environmentally correct, eco-friendly ) to sustain the volume of the demand.
Before the glutted USDA/FDA took over the inspections of seafood at origin, the military inspected the seafood destined for US dining halls and the requirements for procurement were strict and the USAF and Army inspectors mostly made the contractors stick to the requirements. In 75' the Army inspectors were caught by USAF inspectors taking bribes and passing substandard subsistance...like that laced with formaldehyde, ammonia or chlorine. The result was that the powerful dissolved the USAF veterinary service and gave inspections to the USDA/FDA...It takes three veterinarians from the Army to do the jobs that were once accomplished by one USAF veterinarian. It takes three Army MOS techs to do the jobs of one USAF 908. I inspected shrimp destined for dining halls from Gulf Cities Fisheries in Pascagoula and Bayou La Batre, Alabama.