"The listing of the ship caused the cargo hatch covers to slide off the ship and on to the wharf.
"The crane operator lowered the cargo to the wharf and slowly took the weight off the crane to allow the ship to regain its equilibrium."
No one was injured.
The incident comes hours after a 41-year-old Tauranga man's foot was sliced off about 10.30am when it became caught in a winch system that pulls covers over rows of logs.
Genera Ltd fumigation, general and business development manager Mike Goss said the man was a sub-contractor for the company."
It was a winch system that pulls over covers and the cable got wrapped around his leg."
Mr Goss said surgeons confirmed the man's foot would not be reattached.
"He's in good spirits," he said. "Our thoughts are with him and the family."
He said employees worked with the machinery on a daily basis and it was simply an unfortunate accident.
Mr Goss said because port operations were so dangerous. staff were all medically trained and medical equipment was readily available.
Accident reports were being completed for Ministry of Business, Innovation and Employment, formerly the Department of Labour.
Mr Russell said the safety standards were in place but needed to be monitored more carefully.
"We need an inspector on the wharf. We need people out there to keep a vigil on things that happen on the wharf," he said.
"These things happen. Let's get them monitored out there. Let's not wait for an accident to happen. ... We aren't blaming anyone. It's about regulations and making sure it's done properly. It's about safety."
Port of Tauranga corporate services manager Sara Luman said neither accident was the Port of Tauranga's responsibility.
The incident involving the cargo hatch covers came under Maritime New Zealand's jurisdiction as the incident occurred on the water.
Genera was responsible for the injured contractor as it was a private company operating at the port.
She said the port did employ a safety adviser whose primary role was to oversee operations and be available to listen to staff queries or concerns. This did not extend to private companies operating at the port.
Port accidents
Walter Daniel Crosa, father of five, died August 15, 2011 after a grader struck him while he was tarsealing at the port.
Two men were burned while carrying out a routine inspection on a ship in the port in March 2011.
A ship worker fell into the hold of a logging ship and became trapped on December 29, 2010. Firefighters were called to rescue the man, who was not seriously injured.
On December 17, 2010 a 35-year-old Chinese seaman died after falling from the side of the logging ship Green Hope into Tauranga Harbour.
Brian Kevin Shannon, 61, of Otumoetai, died from severe head and chest injuries after a forklift carrying a heavy load struck him on June 21, 2010.
