The Bay of Plenty fishing industry is already facing increased costs and lost earnings from the Rena disaster and fears the worst is still to come.
While vessels are able to sail in and out of Tauranga Harbour, the exclusion zone around the shipwreck, the possibility of oil contamination and metal shipping containers drifting down the coast were threatening local operators.
Bay of Plenty Commercial Fisherman's Association president Brian Kiddie said there was "a lot of worry" among his members.
Crayfishermen were directly affected as they are unable to access equipment close to the wreck, he said.
"The exclusion zone [around the Rena] takes out the best part of the Bay of Plenty crayfishery at the moment," Kiddie said.
"A lot of our bottom-trawlers fish the area of the exclusion zone.
"They do have the ability to fish elsewhere, but it's an added cost," Kiddie said.
Travelling down the coast to other areas could see operators burning $500 of extra fuel before they even catch their first fish, he said.
"One of the guys I was talking to said that a good tow in the trawl out here at the moment working his way down the coast is probably worth five to ten grand and he's going to delete that but he's going to hop on down the coast further and continue to work."
The 88 metal containers confirmed to have fallen from the deck of the Rena were also a real hazard for fishing boats, Kiddie said.
Containers were especially dangerous for the large number of crews that travel during the night.
"A lot of our vessels work [in other areas] but all transit through this corridor [where containers are drifting] ... some I've spoken to are organising their vessels with buoys and floats so if they come across a container they're going to mark it," he said.
As well as the damage a collision would cause, Kiddie said fishing equipment would also be ruined if it snagged on a submerged container.
A longer term threat to the industry is the possibility the hundreds of tonnes of oil spilling from the Rena could contaminate fish and seafood populations, he said.
Bay of Plenty fishing and seafood exports were worth around $24 million in 2009.
According to the SeaFood Industry Council, there are around 50 commercial fishing vessels operating out of Tauranga.
"There are four fish processing factories operating out of Tauranga, so it's a significant part of the industry," said council chief executive Peter Bodeker.
Although the Bay of Plenty catch makes up only a small chunk of New Zealand's $1.4 billion fishing industry, Bodeker said the disaster was a "big deal" for operators in the region.
"[The concern] is how big any impact on fishing will be in the short-to-medium term and will the slick, if [Rena] breaks up, get a lot further out," he said.
Aquaculture New Zealand chair Peter Vitasovich said the Rena spill was having no impact on the industry and posed little risk to any of the country's aqua farms.
The Rena struck Astrolabe Reef, 20km off Tauranga, at full speed early last Wednesday and is leaking oil. Wildlife is dying and the area's pristine white sand beaches are turning black with oil.
A large fracture has spread around the hull of the stricken cargo ship and officials say it is just a matter of time until the ship breaks into two pieces.