Four men received hefty fines in the Mandurah Magistrates Court on Tuesday for catching and planning to eat 98 undersized crabs from Coodanup Reserve.
Hsin-Feng Hsieh, Ka Chun Wong, Yi-Fi Zou and Lixiang Lin entered endorsed guilty pleas to their charges and did not appear in court.
Fisheries prosecutor Dean Gregory told the court the men were sharing one scoop and one steel glove and putting the crabs into two buckets, about 10.30pm on November 17, 2018.
Every crab in their possession was under the 127 millimetre legal size limit, he said.
They ranged in size from 98mm to 124mm.
The crabs were released back into the estuary.
The offenders admitted to the charges in separate interviews and said they were planning to eat the crabs.
Magistrate Anne Longden told the court each offender had written apology letters and displayed remorse for their actions.
The maximum fine for catching undersized crabs is $5000. Each offender was ordered to pay $4900, a $500 penalty and $205.30 in costs.
Shu Xiu Zhou, who was holidaying from China, pleaded not guilty to catching 23 undersized blue swimmer crabs and fishing without a licence.
Mr Gregory told the court Ms Zhou was using a small landing net to catch crabs in Robert Bay, Nirimba, at 6.30pm on November 10, 2018.
Fisheries officers inspected her esky after she had returned to her car and found the crabs to be an average 103 millimetres.
Ms Zhou told officers, using a Mandarin interpreter, she had caught the crabs to show her grandson and was planning on measuring the crabs with her hand.
Mr Gregory said it was an offence to take crabs on a meshed landing net.
Ms Zhou faces a maximum $5000 for being in possession of a protected fish.
A trial allocation date was set for February 26 in the Mandurah Magistrates Court and Mr Gregory would try to reach Ms Zhou, who is believed to be back in China.