Seafood frenzy a sign of faith this Easter

Eating fish instead of other types of meat on Good Friday is a custom observed by some Christians - particularly Catholics - but it's also won wider appeal within secular society.

Genna Mateni, who travelled to the Pyrmont fish market from Belmore in Sydney's southwest, says her family's faith factored into their decision to eat fish at Easter.

"We go to church and we do our whole 40-day Lent so we don't eat meat on Fridays - every Friday - leading up to Good Friday," Ms Mateni told AAP.

She said avoiding meat on Good Friday was a way of acknowledging "what Jesus did for us".

"So that's what we are doing for him," Ms Mateni said while stocking up on fish, prawns, oysters and lobster.

Australian Catholic University senior lecturer Michael Trainor says Christians eat fish for a number of reasons.

From the 4th century onwards, people preparing for Easter would spend time fasting or, alternatively, go without meat, because it was the food of the elite.

"To fast and abstain from meat was an act of self-denial to be in commune with God," Rev Trainor told AAP.

Additionally, Christ has long been linked to fish partly due to the Greek word for fish, Ixthus, representing Jesus, Christ, God, Son and Saviour when read as an acronym.

"The designation of fish is a way of symbolising the nature of the Christ - so on Good Friday, when the focus is on the death of the Christ, fish becomes the symbol of that," Dr Trainor said.

Jocelyn Lapsley, from Wahroonga on Sydney's north shore, was stocking up on seafood at the market because her husband's Catholic family used to always eat fish on Fridays.

Ms Lapsley noted her nephew's children learned about a different tradition on Friday too.

"We did have our hot cross buns this morning and taught the kids about (Jesus) dying on the cross and then rising on the Sunday," she said.

Carmelo Lombardo from De Costi Seafood says he can usually pick whether customers are buying seafood for religious reasons or just because they like it.

"You can pick up on it from what they actually buy," Mr Lombardo said.

"If you walk away with four or five (types of seafood) you're buying because that's what you do and you know that's part of your tradition, your religion."

The fish market expected to sell 650 tonnes of seafood on Friday including 40 tonnes of salmon, 40 tonnes of prawns and 25 tonnes of barramundi.

Mr Lombardo said De Costi staff arrived at work about 1.30am and keen seafood lovers weren't far behind.

"We thought we'd get a head start but at 3am we had customers already, so we couldn't say no," he said.

The Sydney Fish Market is open Saturday, Sunday and Monday from 7am to 4pm.

Australian Associated Press