Dear colleagues, We are pleased to share a recent publication investigating the effects of reduced boat traffic on the marine soundscape during New Zealand's COVID-19 lockdown at the beginning of 2020. This lockdown saw a ban on recreational traffic and a dramatic reduction in commercial traffic, with benefits to the communication ranges of different species in the Gulf. Pine, M. K., Wilson, L., Jeffs, A. G., McWhinnie, L., Juanes, F., Sceuderi, A., & Radford, C. A. (2021). A Gulf in lockdown: How an enforced ban on recreational vessels increased dolphin and fish communication ranges. *Global Change Biology*. https://doi.org/https://doi.org/10.1111/gcb.15798
From midnight of 26 March 2020, New Zealand became one of the first countries to enter a strict lockdown to combat the spread of COVID-19. The lockdown banned all non-essential services and travel both on land and sea. Overnight, the country's busiest coastal waterway, the Hauraki Gulf Marine Park, became devoid of almost all recreational and non-essential commercial vessels. An almost instant change in the marine soundscape ensued, with ambient sound levels in busy channels dropping nearly threefold the first 12 h. This sudden drop led fish and dolphins to experience an immediate increase in their communication ranges by up to an estimated 65%. Very low vessel activity during the lockdown (indicated by the presence of vessel noise over the day) revealed new insights into cumulative noise effects from vessels on auditory masking. For example, at sites nearer Auckland City, communication ranges increased approximately 18 m (22%) or 50 m (11%) for every 10% decrease in vessel activity for fish and dolphins, respectively. However, further from the city and in deeper water, these communication ranges were increased by approximately 13 m (31%) or 510 m (20%). These new data demonstrate how noise from small vessels can impact underwater soundscapes and how marine animals will have to adapt to ever-growing noise pollution.
Please reach out if you have any questions or would like a .pdf of the article (lwil634@aucklanduni.ac.nz). Ngā mihi, Louise Louise Wilson PhD Candidate Leigh Marine Lab 160 Goat Island Road, Leigh, 0985 +64 (0) 27 258 6639