Hidden sound waves

As an industry, we are so narrow-mindedly focused on the nasties that are being pumped into the air in and around our ports that we have become blind to another, less obvious form of pollutant.

We may have become accustomed to the now common-parlance air pollution acronyms and initialisms of Sox, NOx, PM, VOC and GHG, but another ‘contaminant’ needs to be added to the list, one that a group of like-minded ports dearly want to monitor and mitigate for the good of the planet.

Two years ago, a handful of environmentally-conscious ports came together to find a way to better understand the sinister and largely invisible problem of underwater noise. They were disappointed to find that there were no universal measurement standards or protocols for the quantification of noise performance of ships in port. They also discovered that there was no recorded information or standardised datasets regarding noise or nuisance in and around ports.

Consequently, data on noise pollution varies greatly and, so, little has been done to date to mitigate it.

Why should we care? Underwater inhabitants rely on their acoustic world to find habitats, navigate, find mates and communicate with each other when hunting, or avoiding being hunted. Sound underwater can travel for many kilometres – and that applies to man-made sounds too, which mask more natural and necessary sounds. And while there’s a great hubbub about how to sort the air and plastic pollution problems, noise pollution is much easier to tackle; once the noise stops, it’s gone.

Ports should care about noise pollution because the sea is the one environment that we cannot do without for global trade. We have a duty of care to protect that environment, just as much as we do for cleaning up the air that our workers and residents inhale.

To that end, Project NEPTUNES, that aforementioned group of ports that want to reset our respect for the underwater environment, have created a best practice guide for ports on measuring, labelling and mitigating noise emissions of vessels at ports.  

The measurement protocol is based on international standards and the experience of acoustic specialists in similar projects in other industries. Guidelines for consistent labelling have been created and this has been tested in seven ports, with a 1-100 scale to label vessel noise performance.

The goal now is to integrate the labelling system into the IAPH Environmental Shipping Index and encourage ports to reward ships that exceed the standards. I wish them all the best in their endeavours. Even if we win the battle on the air pollution front in ports, ships, whether at berth, at anchor or manoeuvring to arrive or depart from a berth, are still polluting. This is something that we cannot and should not ignore.