Penghu Experimental Sound Studio #3 (2017)
For the third time, between April and July 2017, we have been settling on the islands of Penghu archipelago.
Since 10 years, I have been wanting to develop a project related to the sounds that can be sometimes heard underwater. Ears in water doesn’t work well, the water filling the ear canal, blocking partly the eardrum. But still, I had the experience of hearing strange purring sounds while swimming among tropical fishes, and even heard the drumming distress signal of a diodon that I released from a fishnet.
Several years ago, I befriended Lu Yi-Lin 呂逸林, a marine biologist native and based in Penghu, working at Penghu Marine Biology Research Center and also active member of the foundation Citizens of the Sea in Penghu 海洋公民基金會. Since our meeting, he always helped me for identification of marine species that I observed or shells that I collected on the shores. And through our discussion, we were convinced that sound could be one interesting element of research for surveying the coral reefs.
I met another marine biologist and bioacoustician, Harry Lin, 林子皓, currently working as postdoctoral scholar at Academia Sinica. His work is relying on field recording : materials gathered in the oceans and on the lands of Taiwan are used for software analysis. The systems developed by Harry and his collaborators are able to recognize patterns (or “scenes”) in long term collections of recordings then allow a visualization of acoustic activity of the fauna as well as human-made noise perturbation. This very useful tool for monitoring natural habitat and also for conservation and education, allows to confirm or predict the occurrence of animal species in a location.
My first step for recording during the beginning of the session was still on the shores : tidal pools sometimes reveal strange acoustic phenomena such as the scrapping of algae by the radula (kind of tongue-tooth) of sea snails, or the rattling of the long spikes of Diadema Urchins on the rocks. Occasionally the very strong clicking sound of the snapping shrimp hunting for its preys was surprising me.
Listen : 刺冠海膽 Diadema setosum
Listen : 黑鐘螺 Tegula argyrostoma
Another option was to use.. a Kayak ! My friend Wu Chao Chen, music teacher, is a good navigator and often organizes Kayak event with schools, and he took me to Sai Gong Ta, a tiny islet in the inner sea of the archipelago. Arrived there, he attached the boat to the islet, and let me drift, doing a nice recording of the snapping shrimps…
For the rest of the recording, I will later upload the whole archive that I could create on Archive.org.
But here is a selection of what I could gather :
For now, I just want present the two most promising techniques I could employ.
The first one is to rely on autonomous recording system : a recorder and an hydrophone set inside a box, attached to the sea floor and to a floater below the surface. Let the equipment running during a couple of days, and come back to collect that have been trapped in this kind of sound trap.
I can say that my choice of spot was successful : I could record interesting evolution of the sound of snapping shrimps and a few unidentified signals. But the quantity of materials collected is of course more adapted to the software processes developed by Harry Lin who let my use this recorder.
The other technique is much more physically engaging : I would enter the reef by swimming, dragging a floater with a plastic box containing my recorder and holding the hydrophone by the hand. This allows to carefully observe the recording situations, place the hydrophone and make visual documentation for identification purposes.
With this technique I could record and identify three species of fishes, I could get some sounds of what I believe is the defense sound of a lobster, and a few other interesting recordings of snapping shrimps in various contexts.All thee sounds I collected are to be archived online for educational and conservation purpose.
But during these four months, I also could create some artworks based on those recordings. I will post in the following days about those creations.
Oh… Just before finishing, why not watching the cosmic dance of two nudibranches Onchidium verruculatum ?
(image and sound by Yannick Dauby – Penghu Experimental Sound Studio 2017)