A New Era In Marine Research: Aerial Survey Off Auckland's West Coast (18 May 99)

The health of shellfish and bull kelp beds on the West Coast of Auckland will come under aerial scrutiny sometime in the next few weeks as part of a joint initiative between the Ministry of Fisheries, the Auckland Regional Council and the Department of Conservation.

The intention is to film and photograph the shoreline to help show the distribution and abundance of marine organisms on the rocky shores and reefs.

Another objective is to look at the health of bull kelp beds, which have recently undergone a large die-off.

Using a helicopter to fly along the coast from Muriwai to Whatipu, the team will video and film about a dozen sites in detail while covering the rest of the coastline in wide-angle photography and video footage.

The detailed coverage will be accurate enough to pick up such things as mussel beds, starfish, coverage of rocks by encrusting organisms and patterns of zonation from low to high tide.

Some of these sites have been previously monitored on the ground and will be used as a check on the aerial survey.

Local conservation groups will also use this aerial survey to identify potential sites for marine protected areas and there is also a chance that the rare Hectors dolphin may be filmed.

MFish policy analyst Bob Drey says new advances in technology had made this project possible. Previously people on the ground took days to monitor individual reefs, he said.

"This can be risky with the large surf that is usually present. Often monitoring results are inconclusive because it is impossible to determine what the 'normal' or average state of these resources is."

Consultant marine biologist, Dr Roger Grace, has helped to pioneer aerial survey techniques using microlite aircraft.

The idea is to fly at low levels and speeds to photograph the intertidal zone, using high-resolution cameras and film.

A more recent development by a company called Heletranz has incorporated the use of helicopters combined with a gyro-stabilised, digital video camera system.

This project anticipates making use of both technologies, Mr Drey says.

One of the keys to success in aerial monitoring of the marine environment is to pick a day when the tide is low about mid-day, the water is clear and the swell and wind is light. This does not happen too often on the rugged West Coast.

It is therefore a case of everyone being ready on the day when the weather finally co-operates.

"While this project is aimed at addressing some high-profile issues on Auckland's wild and sometimes inaccessible West Coast, there is no reason why this technology cannot be applied in a variety of other situations. In this way it may represent the start of a new era for marine research in New Zealand, Mr Drey says."