Six recreational fishers have been fined more than $5,000 for attempting to poach abalone with a potential commercial value of $1,500.
The group were detected by Fisheries officers as they were leaving the water at Cape Northumberland, near Port MacDonnell in the South East.
It is alleged the group had in their possession 53 black lip abalone, of which 48 were under the legal-size limit of 13 centimetres.
The alleged offences include taking undersize abalone, fail to carry a measuring device when fishing for abalone, fail to replace undersize abalone and mutilating, shucking, the abalone at sea.
It is also alleged they were taking the abalone from the intertidal zone.
Primary Industries and Regional Development minister Tim Whetstone reminded fishers that it was important to understand the rules before fishing.
"Abalone is a priority species in South Australia and as such, any breaches of the rules involving this species is taken very seriously by the State Government," Mr Whetstone said.
"It is illegal to take any living organism from the intertidal zone, which is an area of reef between the high water mark and water to a depth of two metres.
"This area of reef is often exposed to over fishing which is why it is protected by strict intertidal zone bans.
"If people want to catch abalone, rock lobster, periwinkles or any other benthic marine organism they must be taking them from waters deeper than two metres.
Fisheries Officers have programmed regular patrols to ensure a greater presence in the area during key periods.
To report an offence contact Fishwatch on 1800 065 522.