South Island supermarkets have started rationing milk and bread and supplies of other perishable food are running short due to disruptions caused by the earthquake in Christchurch on Tuesday.
Countdown stores in Dunedin were yesterday limiting milk to four containers per customer and some New World stores to two per customer.
Bread was in limited supply and limited to two loaves per customer at New World yesterday afternoon.
Luke Schepen, a spokesman for Progressive Enterprises which operates the Countdown supermarkets, said the manufacture of perishable items such as cold and delicatessen meats, milk, bread and dairy products such as cheese had been hampered by disrupted water supplies and electricity cuts in Christchurch.
Some products were being shipped from the North Island, but stocks of some non-perishable items were also running out, because of staff shortages at the Christchurch distribution centres.
Mr Schepen said staff were starting to return to work after having had time to sort out their personal affairs, and that should allow a return to regular dispatches and fewer product shortages.
"For our customers in some areas, they are experiencing some product shortages throughout the South Island, but that should improve each day," Mr Schepen said.
Foodstuffs South Island Ltd chief executive Steve Anderson urged customers not to panic buy as food and water supplies were "pouring in to distribution centres".
"We're asking people to just shop normally.
"We need to ensure that we have enough stock at any one time for the community's immediate needs," Mr Anderson said.
There was increased demandfrom Nelson, Dunedin and Invercargill for items such as dairy and delicatessen goods, bread and especially water as people there "stocked up", and Foodstuffs had requested extra stock from suppliers.
"Our distribution and logistics systems are all working well ... there's no concerns we're running out," Mr Anderson said.
In the meantime, southern food producers are stepping up to help the rescue effort in Christchurch.
The New Zealand Food and Grocery Council has reported to the Minister in charge of food co-ordination, Paula Bennett, that some of the country's largest food producers are donating product, time and people to ensure rescuers and Christchurch citizens are getting food and water.
Cerebos Greggs has sent coffee, Harraways breakfast cereal, Cadbury Kraft has offered the Salvation Army chocolates, breakfast spreads and other products and Mainland Poultry shell eggs and processed egg products.
