Fines for illegal fishing in South Australia are being increased for the first time in more than 30 years with some penalties jumping from $50 to more than $600.
Primary Industries Minister David Basham says the current penalties are no longer deterring people who want to break the rules.
"The black-market value of seafood has increased well beyond the penalties set back in the 1980s," he said.
"For example, under the old rules, someone caught taking 20 undersize crabs could only be issued a $100 fine.
"Offenders found it cheaper to break the law than pay up to $150 for the crabs at the shops."
Among the changes, anyone caught with taking 10 undersize King George whiting or exceeding the bag limit on calamari will face a fine of $625, up from $50.
The fine for taking too many blue swimmer crabs will also jump to $625.
Mr Basham said both recreational fishers and the commercial sector had been disgusted at the previous fines and both had called for significant increases.
The new penalties will come into force in March.