“Key data from this study provides strong evidence that small vessels, where there are enough of them, directly influence sound levels and are definitely having an impact.” Noise pollution is known to have deadly effects on marine life, such as those which use sound for life-critical behaviours like mate selection and predator warnings. The study, which was published in the Global Change Biology scientific journal in collaboration with Dr Matthew Pine from the University of Victoria in Canada, saw data gathered from acoustic recording stations at five sites in the Hauraki Gulf. Between February and May 2020, six samples per hour – or 144 samples a day – were gathered and split into lockdown and pre-lockdown categories.