A new study conducted by a group of scientists from the University of Auckland, New Zealand, has revealed that ship noise affects the communication ability of species living under the water.
The research was carried out in the waters of New Zealand’s Hauraki Gulf and found that ship noise has significantly reduced the amount of ‘communication space’ available for at least two major marine species.
University of Auckland PhD candidate Rosalyn Putland and the university’s Institute of Marine Science department’s associate professor Craig Radford combined sound recordings from four hydrophone ‘listening stations’ over nine months with automatic ship-tracking data as part of the study, which aimed to track shipping operations’ contribution to underwater noise lvels.
The hydrophones were suspended 1m to 2m above the seabed to record two minutes of data every 20 minutes.
The research was specially focused on gathering data from two species, Bryde’s whales and common reef fish, bigeye, which both communicate via sound.
According to the research, every time a vessel passed within 10km of a hydrophone, it minimised communication space for bigeyes by up to 61.5% and by up to 87.4% for Bryde’s whales.
Jellicoe Channel was found to be the area most affected by ship noise.
The study also suggested that the existing 10k speed restriction regulation within the Hauraki Gulf Marine Park area could benefit marine species, as vessels sailing at reduced speeds generally produce less noise.
Putland said: “The voluntary speed limit of 10k is fairly recent but we believe it is having a significant effect on helping reduce noise in the Gulf to allow species to hear each other.
“Even so, when a ship is directly above marine animals, it reduces communication for those animals almost completely, or by 99%.”
More than 130,000 recreational boats currently use the Hauraki Gulf on a regular basis and the number is estimated to increase by 40% over the next two decades.