One morning I went down to South Bay to try contact microphones on the rusted remains of the metal capstan on the dock; at least, I think that’s what it is! There was a deep rumbling. And it was just as intense if I put the microphones directly on the concrete of the dock itself. This was a little unexpected. Then I realised this was the same sound, the same feeling I had experienced occasionally through the week on the island. But I didn’t know then what it was.
At that moment I looked up, and just coming into sight was the Irish Ferry, making the journey from Ireland to Pembrokeshire twice a day. I heard and felt it long before and long after I could see it.
This is a recording of that sound & vibration. It is extraordinary that a small ship can create such an impact. The entire island resonates with this four times daily as the ferry arrives and leaves twice a day. I wonder about the impact on marine life around the ship, and on island life as well. The sphere of impact must be significant – especially within water. I was astounded at the extent to which I could feel its physical impact.
Last week I was talking about this experience with some new friends at workshop in Glenshee in the Cairngorms National Park. The book, “One square inch of silence” by Gordon Hempton was recommended to me. In it the author describes his efforts to preserve silence in a small area in a national park in the northwest United States. This effort extends to encouraging overhead flights to avoid the area in order to preserve the quiet within the park. We could do with similar initiatives here. Skokholm and Skomer (and many other special protection areas and national nature reserves having national and international importance) are certainly frequently overflown, but after listening to this ferry I wonder if the close passage of such shipping may have a greater and more local impact than plane noise.
How much impact must this intense low frequency intrusion make to the communication and comfort of marine animals such as cetaceans? The issue is certainly being studied globally, with many papers available reporting communication interference for killer whales, dolphins, and other marine mammals. To what extent are these studies influencing human behaviour; and to what extent are we working to mitigate the impacts of this traffic?