The jailing of Phong Hoai Thuy Nguyen on Wednesday took to 11 the number of people penalised in Melbourne courts this year over a syndicate that poached abalone from Victoria's western coast and sold it illegally in Melbourne's western suburbs.

South-west fisheries officers were the key initial investigators in the 12-month Operation Quantum, which targeted the divers and the on-selling of their catches collected between Port Campbell and Port Fairy.

The divers are believed to have come to the south-west on average at least four times a week for almost a decade and taken their maximum allowable catches.

Nguyen, a 41-year-old mother of two, wept loudly as County Court judge Sue Pullen on Wednesday jailed her for 23 months and two weeks for regularly buying abalone from divers and then selling it in St Albans.

The court heard that between March and October 2014 Nguyen was seen by fisheries officers 37 times receiving deliveries of abalone at home, and 27 times selling it and other illegally poached seafood from a red shopping trolley outside a grocery store, where she would negotiate with her customers.

It is understood abalone — which is considered a delicacy in some Asian countries — can be illegally bought for about $55/kg in Victoria, whereas the commercial price is about $130/kg.

Victoria and Tasmania are two of a handful of regions worldwide where abalone is commercially harvested. 

Fisheries Victoria investigating supervisor Andrew Holman hoped Nguyen's jail term and the 12-month investigation into the syndicate — the largest undertaken by fisheries officers — would deter other poachers.

"We will detect, disrupt and dismantle any organised crime in the fishing industry, so this is really about sending a strong message," Mr Holman told Fairfax Media.

In a summary tendered to the court last month, prosecutor John Livitsanos said that during the investigation, fisheries officers saw 11 divers regularly visit sites on Victoria's western coast and go into the water together to harvest abalone.

To investigators the divers looked like they were part of a commercial operation because of the way they worked together, harvested efficiently and packed their yield in backpacks, Mr Livitsanos said.

The divers originally travelled to the sites — believed to be near Warrnambool and Port Fairy — in groups of four or five a vehicle, the prosecutor said, but began using a convoy of vehicles when regulations were changed to limit fishers to 10 abalone per car.

The convoy would then travel to several addresses in Melbourne's western suburbs, including Nguyen's home, where the abalone, rock lobster and other molluscs were unpacked and weighed, and Nguyen would pay the divers cash.

She pleaded guilty to trafficking a commercial quantity of abalone, an offence which carries a maximum 10-year jail term, and the lesser charges of selling rock lobster and selling other molluscs without permission.

Judge Pullen said Nguyen's role in the syndicate was at the top of their hierarchy and said the offending was organised and very serious given the impact illegal poaching had on the environment and the viability of the commercial abalone industry, which employs thousands of people.

Nguyen's subsequent sales had the potential to endanger the public's health because she couldn't ensure food hygiene standards.

The commercial abalone industry was tightly-regulated and licensed, Judge Pullen said, because of its importance to Victoria.

Prosecutors cannot say how much money Nguyen made, but Judge Pullen put a pecuniary penalty order — the revenue the state was denied — at $18,000.

Four divers were last month jailed by a magistrate, while six others were put on community corrections orders. The jailed divers have launched appeals.

Two other people, one charged with both diving and trafficking abalone, are due in court next month.

Authorities seized 11 cars, diving equipment and scales as part of their investigation.

Judge Pullen was "guarded" towards Nguyen's prospects of rehabilitation, but said she had shown some remorse and had co-operated with authorities once arrested. This was her first conviction for fishing offences.

Nguyen must spend one year in jail before she is eligible for parole.She has already served 55 days.

Her husband was charged as part of the investigation, but those charges were withdrawn.