Memories of a powerful tsunami that surged from Japan and smashed mussel farms around Marlborough two years ago were rekindled in the minds of Sounds farm owners when a tidal surge warning was issued last week.
Seafood farmers became concerned after the Ministry of Civil Defence and Emergency Management briefly issued a national advisory warning that a tsunami could hit the Marlborough coast following a magnitude 8.0 earthquake which struck near the Solomon Islands and killed nine people on Wednesday.
The risk was reduced to possible tidal surges hitting shallow bays such as Port Underwood on Marlborough's east coast the following day, but no damage was reported to the Marlborough harbourmaster's office by Friday.
Port Underwood mussel farmer Ray Thomas said he had been worried for the safety of his farms when news broke of the tsunami, and he was relieved to learn the farms would be fine.
He had also been concerned about the safety of his son's farms in the area. They were badly damaged by a tsunami spawned off the coast of Japan in 2011.
"We were nervous when we heard about it but there's not much you can do about it; it's not as if you can take your farms out of the water or shift them away in a hurry.
"There hasn't been any damage this time, to my knowledge - hopefully we're past it."
Strong, erratic currents caused by a magnitude 8.9 earthquake off the coast of Japan damaged more than 100 mussel lines in Port Underwood and Croisilles Harbour in March 2011.
Mr Thomas' farms were badly damaged, with about 75 per cent of the 70 lines needing to be repaired and about 15 per cent or 420 tonnes of mussels being lost.
At the time, the market price for mussels was $600 a tonne and he described the damage as "mind boggling" - the incident was the worst he had seen in a 24-year career.
"We lost all our anchorage systems and a lot of the farms ended up tangled up in balls.
"You've just got to hope they'll be all right, and that time they weren't."
He said he spoke to his son, fellow Port Underwood mussel farmer Paul Thomas, on Thursday, and he was happy that he had not mentioned any problems with the lines last week.
Paul Thomas had five lines damaged by the Japanese tsunami and he had to fix 10 large anchors at a cost of $16,000.
A spokesman from Hebberd Marine Farm Services, which runs mussel farms in Croisilles Harbour, west of the Marlborough Sounds, said no unusual tides had been observed and everything had been normal.
Staff had been nervous after hearing about the Solomon Islands tsunami alert but were glad to have "nothing to report" in the way of damage.
The company was forced to undergo major repair work to about 30 mussel farms damaged in the harbour after the Japanese tsunami.
Havelock-based Pelorus Tours owner Gary Orchard said the inner Sounds were largely protected from any strong tidal shifts sweeping around the country.
"There's a fair few corners they would have to get around to really get in here; it can be pretty sheltered like that."
Mr Orchard, who also runs mussel farms in the area, said he had experienced no problems from the tsunami and had not seen any notable changes in the tides.
A spokesman from the Marlborough harbourmaster's office said no reports were received of any damage. Similar fears were raised after a magnitude 7.6 earthquake struck near the Kermadec Islands in July 2011 but tidal surges did not eventuate.
- The Marlborough Express