The A$1 billion industry uses the technique to deter seals and protect fish farming operations. Cracker bombs are underwater explosive devices that emit sharp, extremely loud noise impulses. Combined, Tasmania’s three major salmon farm operators have detonated at least 77,000 crackers since 2018. The industry says the deterrent is necessary, but international research shows the devices pose a significant threat to some marine life. Unless the salmon industry is more strictly controlled, native species will likely be killed or injured as the industry expands.