Two fishermen have been nabbed by Fisheries officers, allegedly leaving Harvey Dam in possession of more than 70 out-of-season marron.
Nearly 60 of the crustaceans were under the legal size limit. Marron fishing season only begins in January.
A part of the ongoing Operation Kerinci into illegal marron fishing, a further six fishers were also caught in possession of marron and illegal gear throughout the evening.
Public reports said the social group was planning to catch significant amounts of marron as a part of an "annual get-together".
When officers arrived they inspected four vehicles and apprehended a man, along with 22 marron traps in what they called a "significant marron poaching operation."