In recent weeks new studies have been released showing the effect noise pollution is having on wildlife. One that particularly caught my eye was a study looking at the endangered southern resident orcas found off the coast of British Columbia and Washington State. The area is one of the busiest shipping lanes in North America, linking western Canada and the USA to Asia. The findings concluded that high-pitched ship noise could be disturbing orca communication and echolocation. This species uses sound, through echolocation, to hunt for its main food source, salmon. It has long been known that there are negative effects of low-pitched noises on larger cetaceans, however this is the first of its kind looking at higher pitch frequency.
When one is spending time in this area it is hard not to notice the large number of ships, it is not uncommon to see four or more tankers in one particular area at a given time and this can be seen in multiple areas. In fact I could count on one hand how many days in a year I have seen no tankers in the Juan de Fuca Strait.
This conclusion comes as no shock to me. During my time researching this population of orca, we would often use a hydrophone to record their sounds and communications. When listening to the orcas on a hydrophone it would could be very difficult to hear them over the high-pitched background noise from passing ships. Most of the time we would not be particularly close to the ships themselves, yet the noise would still be loud enough to almost drown them out.
Here are some recordings taken from my time researching the orcas. You can hear the orcas communicating through squeaks and clicks with the background noise of passing ships. The noise is about 60 to 90 decibels which is the same as having the noise of a lawnmower in your ear every single day. The final recording is a recording without ship noise.
It may not just be the orcas that are affected, other dolphin species and porpoises are most likely impacted.
Noise reduction in the area might not be too difficult to achieve. Decreasing a ship’s speed by six knots would reduce noise intensity by half. Another option could be altering the technology of tankers as seen on other ships such as military vessels thus making them quieter.
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