A 'whale of a time' with noise attenuation

On the Granite Island Causeway project in South Australia, our team designed and implemented a "shroud and bubble curtain" to stop marine piling noise from disturbing the Southern Right Whale (SRW) and other marine fauna, such as the Australian sea lion and little penguins.

Prior to the solution being developed and approved, a local whale protection group strongly objected to piling occurring during whale season, which had the potential to impact the project's schedule and budget.

The bubble curtain was designed to reduce the noise levels by scattering, absorption, reflection, and refraction of the sound waves. The curtain design, along with some other piling modifications, gave sufficient confidence for federal approval under the Environment Protection and Biodiversity Conservation Act for piling during the whale season.

Once implemented, hydroacoustic monitoring by an independent consultancy demonstrated a 13 dB reduction from predictions. Piling noise was not noticeably discernible from ambient noise at the required distance. Project Marine Fauna Observers (MFOs) spotted the first SRW of the season within 1 km of the construction zone less than 24 hours after piling, highlighting the effectiveness of the solution.