For decades, biodiversity has suffered massive losses worldwide. Species are disappearing (e.g. [36]), populations are collapsing (e.g. [15]), species’ ranges are changing (both shrinking and expanding) at unprecedented rates (e.g. [7]) and communities are being displaced by invasive alien species (e.g. [24]). All the above are caused by human activities and scientists regularly alert the international community concerning our responsibility [30]. In particular, urban growth is one of the major reasons for biodiversity loss [21, 29] in that it destroys natural habitats, fragments the remaining ecosystems (e.g. [40]) and also has other impacts, such as pollution. For example, cities produce artificial light at night that disturbs circadian rhythms, impacting plants and animals [2, 13]. Similarly, many man-made sounds are generated in cities, by traffic and numerous human activities (industrial, commercial, etc.) [39]. In fact, anthropogenic noise is omnipresent and ranges beyond cities. All human activities generate noise, even far from cities (e.g. motor boats on lakes, aircraft in the sky, etc.) and those sounds can reach wild, uninhabited places [16].
Many studies have shown that such sounds may have considerable impact on animals. However, sound is not a problem in itself. A majority of species use, hear and emit sounds (e.g. Romer and Bailey 1990 [32]). Sounds are often used to communicate between partners or conspecifics, or to detect prey or predators. The problem arises when sounds turn into “noise”, i.e. a disturbance or even a form of pollution. In this case, man-made sounds can mask and inhibit animal sounds and/or animal audition and it has been shown to affect communication [37], use of space [10] or reproduction [3]. This problem affects many biological groups such as birds [19], amphibians [9], reptiles [22], fish [1], mammals [34, 35] and invertebrates [6]. It spans several types of ecosystems including terrestrial [18], aquatic [17] and coastal ecosystems [33]. Many types of sounds produced by human activities would seem to be a form of noise pollution affecting biodiversity, including traffic [20], ships [38], aircraft [4] and industrial activities [23]. Noise pollution can also act in synergy with other disturbances, for example light pollution [26].
For decades, noise regulations have focused on human disorders but recently, public policies in biodiversity conservation have started to pay more attention to noise pollution. In 1996, for the first time, the European Commission’s Green Paper on Future Noise Control Policy dealt with noise pollution from the point of view of environmental protection. Today in Europe, quiet areas are recommended to guarantee the tranquility of fauna [12]. Since 2000 in France, an article in “Code de l’environnement” (art. L571-1) has contained the terms “harms the environment” with respect to disturbances due to noise. To further mitigate the effects of noise pollution on biodiversity, the French Ecology Ministry wants to obtain more information on the impacts of noise on biodiversity in order to initiate policies focused on species which are known to be highly exposed. The Ministry is also interested in the types of impacts that have been effectively demonstrated and in the types of noise that have been proven to affect wildlife. We proposed to produce a systematic map of the literature dealing with this issue to provide the Ministry with a report on current knowledge and to identify sectors (sources, types of impact, etc.) where research is needed to fill in knowledge gaps.
A preliminary search did not identify any existing systematic maps or reviews, however a few reviews of the literature have been published. Most of them concern only one biological group, such as Morley et al. [25] on invertebrates, Patricelli and Blickley [27] on birds and Popper and Hastings [28] on fish. A synthesis published by Shannon et al. in 2016 [34] is more general and comes closer to a systematic map, but the search strategy would seem to be incomplete. The literature search was performed on only one database (ISI Web of Science within selected subject areas) and the review did not include grey literature. Finally, a meta-analysis was performed by Roca et al. [31], but it dealt exclusively with birds and amphibians and the authors were interested in only one effect (vocalization adjustment).
This report describes the protocol used to develop a systematic map of noise pollution and biodiversity. The systematic map will provide further information on the knowledge currently available on this issue. It will include all the relevant studies (with grey literature) collected after three screening stages. An open-access database will be produced, containing metadata for each study on key variables of interest (species, types of sound, effects, etc.). This database will be available in conjunction with a map report describing the mapping process and the evidence base. It will include aggregate data and tables of the study characteristics to highlight any gaps in the research evidence concerning the issue.
