From March, the State Government will enforce no-fishing green zones in 16 per cent of the Moreton Bay marine park and even greater limits on commercial operators.

The government expects about 100 of the bay's 430 commercial operators to leave the bay as part of a $15.1 million licence buy-back scheme. Operators need to apply by November 28.

Moreton Bay Seafood Industry Association vice-chair John Page said fishing families faced a "life-changing decision" and needed more time to decide whether to surrender their licence.

He also called on the Environmental Protection Agency (EPA) to tighten its licence buy-back scheme to ensure those who took up the offer were not allowed to re-enter the bay, and he said more funds should be provided.

"At this time of economic uncertainty, we do not want to see fishing families unemployed and on the street, because of matters that EPA has overlooked," Mr Page said in a statement.

An EPA spokesperson rejected calls for an extension of time, saying decisions must be made soon before the new Moreton Bay zoning plan takes effect.

The spokesperson said the government had been working closely with industry groups since last year to deal with the issues at hand.

Premier Anna Bligh announced last month that commercial fishers who surrendered their licence under the buy-back scheme would be banned from Moreton Bay for five years.

She said the only way around the ban would be to buy a licence from someone already operating in the bay - not from elsewhere in Queensland.

Commercial and recreational fishermen will be subject to new no-take green zones covering 16 per cent of the marine park, with breaches attracting $375 on-the-spot fines. Green zones currently cover less than one per cent of the bay.