Thousands of Sydneysiders are expected to snap up more than 650 tonnes of seafood from the Sydney Fish Market in the lead up to Christmas.
The Sydney Fish Market's annual 36-hour seafood marathon kicked off on Monday morning and runs until 5pm (AEDT) on Tuesday.
Fish market general manager Bryan Skepper said he was expecting about 100,000 shoppers to purchase more than 650 tonnes of seafood during the period.
He was also predicting 120 tonnes of prawns and 70,000 dozen oysters to be shifted from the market floor.
"The numbers always blow me away," Mr Skepper said.
He said his pick for Christmas day was snapper.
"What I'll be having is snapper; there has been good supplies of snapper and at 15 to 20 dollars per kilo it's affordable," he said.
NSW Primary Industries Minister Katrina Hodgkinson will board a fishing trawler at the market at noon to celebrate the 36-hour trading marathon.

