Mainfreight chief executive Don Brain said the company was turning to shipping to keep goods moving to quake-affected areas.
"Our guys have already begun to find different ways to move the freight into the South Island. We halted freight movements into Christchurch and Wellington yesterday but we've got some more freight moving today - the linkspan [used by the rail ferries Arahura and Aratere] in Wellington has been repaired and that's allowing us to get across the strait " he said.
"There's no doubt about it, coastal shipping will play a major part in trying to get goods into the lower South Island on the back of the work they've got to do to fix the rail line and roads."
He said the company was only a day behind in its operations as a result of the disruptions, but he acknowledged that the earthquake could change the country's freight industry in the long term.
"[The damage caused by the earthquake] will change the way that we need to move freight into the South Island but it won't stop us moving freight into the South Island, we'll just have to find alternatives."
Freightways managing director Dean Bracewell said the quake could see it increase its use of air freight.
"We expect increased demand for our air freight and have already had customer inquiries about additional air freight capacity into the South Island," he said.
The company was not falling behind with its deliveries, but some were incurring delays.
"Our businesses are in the courier industry so a lot of our overnight air freight, which is through the likes of New Zealand Couriers and Post Haste Couriers, continues to operate as normal.
"There are natural delays into Blenheim and up into Nelson as we need to go through Lewis pass which adds about 1.5 to 2 hours to the journey. And obviously access into Kaikoura and Cheviot isn't available to us."
Meanwhile, Kaikoura's New World supermarket re-opened this morning, good news for locals and tourists stranded in the quake-affected town.
Foodstuffs South Island chief executive Steve Anderson said the Kaikoura store had been declared structurally sound and would resume trading this morning.
"The store has opened with reduced stock availability as fresh and frozen products have been affected due to the power outages. We would like to let customers know they can come to the store to access emergency supplies and staff will be on hand to assist.
"The store is working hard to manage stock and ensure all of the community can access supplies, and at this time customers are being served from the front foyer with the assistance of staff."
Other than the Kaikoura supermarket, the rest of Foodstuffs' stores were more than adequately stocked and its supply chain intact.
"Except for the odd delay, trucks are continuing to arrive at stores as normal and stores are managing stock to ensure that everyone has access to staple items," Anderson said.
Progressive Enterprises said in a statement that all of its North Island Countdown stores were trading today, except for the Queensgate Mall supermarket in Lower Hutt which is being cleaned, and the Wainuiomata store which suffered some damage in the earthquake.
All of its SuperValue and FreshChoice stores are open except for the Seddon SuperValue.
Online shopping is running as usual - albeit with delays - with the exception of in the Wellington CBD and Blenheim.
"We are doing everything we can to get stock to affected parts of the country, including from our distribution centre in Christchurch. There may be some delays, but we are able to get deliveries into all affected areas. We will continue to update our customers and teams."
