Six of 21 men arrested for allegedly exporting perlemoen pleaded guilty in the Western Cape High Court on Monday, the department of agriculture, forestry and fisheries said.
Spokesman Lionel Adendorf said the case was postponed until Tuesday.
The men, all South African, were arrested in 2007 after the Hawks traced two containers carrying over three tons of perlemoen.
Adendorf said the containers had been shipped to Hong Kong with their contents labelled as sardines.
The men are accused of harvesting, processing and exporting more than 200 000 units of perlemoen. They were charged under the Marine Living Resources Act and face charges of money laundering. - Sapa