Boats and ships are convenient for traveling across large bodies of water, but a new study published in the journal Proceedings of the Royal Society B this week by Aarhus University researchers underscores how vessel noise disturbs marine wildlife in more ways than one.
Image Credit: Lis Bach, AU
The curious team of researchers reached their conclusion after outfitting seven wild porpoises with suction cup-adhered electronic tags. An in-depth analysis of the tags’ data afterward uncovered shocking results.
Related: Watch a dolphin launch a porpoise several feet into the air
As it would seem, noisy boats and ships trigger deviations in porpoise behavior, primarily in the departments of communication and foraging.
Porpoises typically produce ‘clicking’ sounds, much like echolocation. These sounds help the animals communicate with one another, and the tag data showed that the porpoises made these noises less frequently, or not at all, in the presence of excessive vessel noise.
Foraging behavior changed too. Citing the study, the tagged porpoises would stop trying to find food when disturbed by similar loud noises.
"When the ship noise exceeds a certain level, the porpoises stop feeding. At very high sound levels the animals dive to the bottom and move fastly along this, and they cease emitting the biosonar clicking sounds that they use when searching for food," explained study co-author Jonas Teilmann from Aarhus University’s Department of Bioscience.
Related: Meet the world's first-known two-headed porpoise
The findings carry negative implications about how human activity impacts the well-being of these creatures in the wild. Vessel noise shows the potential to separate family members that can’t hear one another and to influence health for those that stop foraging when disturbed.
"Our measurements show that the porpoises do respond to heavy ship noise. It is still too early to say, though, what this means to the well-being of the porpoises, their production of offspring and, in the long term, their survival," added study co-author Professor Peter Teglberg Madsen, also with Aarhus University.
There isn’t enough long-term data to jump to conclusions just yet, but additional research could fortify these findings and reveal more about how human-made noise affects marine wildlife. If anything’s for sure, however, it’s that the results probably won’t be pretty.
Source: Science Daily
