My name is Cecilia, and I have spent the past 3 months as an intern at the Archipelagos Institute of Marine Conservation. During my internship, I have deepened my knowledge in the field of bioacoustics through assisting other interns with their personal projects. The reason as to why I chose to not start a new project of my own was because I found it really interesting, and insightful, to continue an existing study rather than beginning a new one with such little time. The aim of my joining the project was to create a bioacoustics catalogue for click recordings relative to the species of Tursiops truncatus, Stenella coerueolalba, Delphinus delphis, Physeter macrocephalus and Ziphius cavirostrum, and then to compare the bioacoustic parameters of these different species that can be found in the Aegean sea.
For the analysis of the clicks, we used RavenPro, a software able to study the sounds detected by the hydrophone we use during boat surveys. From the software, it is possible to produce a spectrogram and a waveform, from which we can export some useful parameters, such as Delta Time, Peak Amplitude or Peak Frequencies, that can be used for more specific further analysis. For example, the inter-click interval was calculated for the project I assisted with, which is a really important parameter that is commonly used for click analysis, and gives you the time between one click and another in the same train click.
I am grateful to have had the opportunity to join this specific project because I have a great interest, and am highly aware of the importance, in creating a bioacoustics catalogue. Firstly, it will be very useful for other intern projects as it will save them a lot of time. Secondly, it will serve a fundamental role in aiding the study of the presence/absence and distribution of the marine mammals around the area. Furthermore, this bioacoustics catalogue will allow for the comparison of the data collected with pre-existing catalogues that have been created for the same species in other areas of the Mediterranean. Future research could focus anthropogenic noise and how it may impact cetacean behaviour over time, and help us gain the knowledge necessary to mitigate acoustic pollution.
The creation of this catalogue is one of the first steps to protecting these species. Bioacoustics has the potential to play a fundamental role in the conservation of marine mammals in the Aegean sea: firstly to collect data on the presence/absence of the species, and identify changes in their way of communication with each other for different kinds of noises, and secondly, for informing management strategies to help solve this issue. For example, once the catalogue has been created and updated, it may be interesting to study and analyse the most common sources of noise that impact cetaceans, and how they impact them (from changes in bioacoustic parameters). Investigating which sound pressure levels induce a change in the behaviour of the species present in a specific area (in this case in the Aegean Sea) is essential to identify the main sources of disturbance and if, over time, the species will be able to adapt to this source of anthropogenic pollution.