Eventful Start To NZ's Largest Coastal Survey

Media Release from Land Information New Zealand

31 October 2008

Successful But Eventful Start To New Zealand's Largest Coastal Survey

The first phase of a survey of the Bay of Islands and eastern Northland seabed is making good progress - even after stopping to assist in the rescue of three troubled boats in the area.

Since mid-October, two National Institute of Water and Atmospheric Research (NIWA) vessels - the deepwater research vessel Tangaroa and the survey launch Pelorus - have been mapping physical features of the marine environment using multibeam mapping to build up a picture of the seabed.

The survey, coordinated by Land Information New Zealand, is the largest of its kind to take place in New Zealand coastal waters and is part of the government's Ocean Survey 20/20 programme.

NIWA ocean geologist Anne-Laure Verdier, (the surveyor in charge), said the team was grateful to the people of Northland for their support and interest in the project, which will greatly improve the understanding of marine biodiversity and habitats and help with future decision-making.

"We're also pleased to have been able to give back to the community. The survey launch Pelorus has been able to assist in three marine rescues since arriving in the area," Ms Verdier said.

Pelorus provided assistance to a yacht that had run aground at The Brothers off Kerikeri Inlet, responded to another mayday and also towed a small catamaran which had been washed off its mooring by wind to safety.

Good weather and sea conditions mean Tangaroa is ahead of schedule, mapping seafloor depths between 50 and 200 metres. While criss-crossing the Bay of Islands, Pelorus also made a successful run through the Hole in the Rock, recording depths greater than 80 metres at times.

"This is the first time the seafloor under the Hole in the Rock has been surveyed using multibeam mapping and it's providing some exciting new information for us," Ms Verdier said.

A third NIWA vessel, Bella Vita, joins the Bay of Islands survey this weekend to map areas close to shore between 2 and 10 metres.

Boat operators are being asked not to venture closer than 200 metres to Bella Vita. The sidescan sonar being used is extremely sensitive to air bubbles in the water caused by boat wakes which can last in the water for up to 10 minutes and completely block the seabed image.

ENDS