Marine expert calms residents’ concerns for Cockburn Sound as geophysical surveying begins for Westport

Access to Cockburn Sound from Challengers Beach will be closed from next Monday as geophysical surveying begins as part of the Kwinana outer harbour project.

Nearby shack owners were notified of the beach closure last week.

The Sound will be closed for two to three weeks from October 28 to divers and swimmers during daylight hours.

Geophysical surveying maps the seabed via sound waves and can cause underwater noise above levels recommended for divers and swimmers.

This is one of the first steps for Kwinana’s $4 billion Westport project, which was referred for assessment by the Environmental Protection Agency in March.

The Port project originally had an estimated 2032 finish date.

However, it was revealed in July that the port may not be ready and open until 2042.

Marine expert Robert McCauley said fears from a Naval Base holiday shacks resident that the surveying could harm local wildlife were unfounded.

“They’re just looking at shallow subsea layers and because they don’t need to go very deep, they don’t need a lot of power,” the Curtin University professor said.

“So they tend to be a bit more benign than the offshore ones used for oil and gas production.

“It’s probable there will be sounds throughout but mostly at low levels and there’ll be a low chance of harming anything.”