Using passive acoustic monitoring (PAM), implemented with autonomous non-invasive recorders, it is possible to record acoustic data on a large spatial and temporal scale that allow the collection of long-term information on the presence and distribution of animal species and changes in the dynamics of biological communities. The studies which make use of this approach, defined Ecoacoustics, are oriented towards considering the soundscape as an expression of the richness, diversity and complexity of an ecosystem.
The tools available today make possible to record the soundscape over long periods, weeks, months and even years, in order to understand its spatial and temporal dynamics and to recognise at an early stage the changes induced by human actions, both locally and globally (e.g., as a consequence of climate change).
The monitoring of acoustic environment represents a new approach to the study, conservation and management of the natural habitat. However, we should also consider that noise, produced by local (tourism, agricultural-industrial activities, roads) or distant (land and air transport) anthropogenic activities, is often a relevant component of soundscape and it can seriously damage both the ecosystems and man himself.
Recognising the negative effects of noise on humans and wildlife is the first step to understand the concept of ‘environmental acoustic quality’: the level of ‘acoustic comfort’ necessary for animal species’ survival and fitness. The study of the soundscape and anthropogenic noise is widely implemented by the National Park Service (NPS) and is gaining more and more interest in other countries thanks also to the continuous evolution of data acquisition and processing technologies.
These are just some of the action lines and themes provided by PAM:
- Determination of acoustic richness and biophony through “acoustic indices”, to assess environmental quality and its changes over time, comparing different sites (e.g., under different conservation or management plans)
- Analytical monitoring of the species through spectrographic analysis and listening or by specific programs for automatic recognition of species-specific acoustic signals
- Analytical monitoring of target species (umbrella species, key-species, endangered species, invasive alien species)
- Seasonal variability of biological communities and phenology of the species that best characterise their ecosystem
- Identification of “Quiet Areas” to be preserved and/or enhanced
- Acoustic surveillance through the recognition of peculiar acoustic events such as gunshots, noise from motor vehicles and noise from chainsaws
- Noise pollution monitoring (road, ship and air traffic)
- Acquisition and preparation of sound materials that can be used for research, scientific dissemination and tourist attraction