Paul Chak Po Mak, 61, and Samuel Xing Sin, 41, were arrested as part of the "Operation Scoop and Run" investigation by the Department of Fish and Game and are suspected of poaching 84 abalone for commercial purposes between April 23 and May 21.
During the investigation, members of the department's special operations unit allegedly observed the two men taking large overlimits of abalone.
Both men were booked into Mendocino County Jail on suspected charges that include possession of abalone and intention to sell on the black market.
Abalone typically sell for up to $100 each on the black market, with bigger abalone tending to fetch much more.
Mak, who is currently on probation in Sonoma county for abalone-related convictions, is suspected of taking 52 abalone. Sin, who has a currently pending case related to abalone poaching and sales in Mendocino County, is suspected of taking 32 abalone.
"It is clear -- and disappointing -- that penalties from prior convictions failed to deter either of these men," said Department of Fish and Game Capt. Bob Farrell, who oversees the special operations unit.
According to the department, wardens serving search and arrest warrants at the homes of Mak and Sin seized abalone report cards and dive gear.