A call for underwater noise assessment guidance

Elena San Martin, ABPmer: ‘Human activity in or near to the aquatic environment can generate underwater sound potentially affecting fauna in a number of ways. These range from masking biologically relevant signals, evoking behavioural responses and causing hearing damage resulting in physical injury or even death at very high received levels of noise. To assess the potential effects of noise generating activities on aquatic fauna, an underwater noise assessment is usually required as part of an Environmental Impact Assessment (EIA) or a Habitats Regulations Assessment (HRA). In essence, this involves predicting the propagation of underwater noise from the sound source and applying recognised response thresholds to determine whether there is likely to be a significant adverse effect in aquatic species.

Historically, there has been a lack of standardised protocols and associated terminology for measuring and describing underwater noise. A number of initiatives have investigated these issues, including the Marine Strategy Framework Directive (MSFD) and OSPAR at a European level and the Underwater Sound Forum at a national level. Best practice guidance has also been published that includes advice on the appropriate metrics to use in underwater noise measurements (TNO 2011; NPL, 2014). In addition, a recent paper has provided further clarity on the underwater noise propagation models that are technically considered most appropriate to use in different scenarios (Farcas et al., 2016). However, using more complex models should be proportionate to the scale of the development (Should we be “raising the bar” for underwater noise assessments?). To read more click here.