Biology subjects

Bolgan, M.

Publications and source records attributed to Bolgan, M..

2 recordsLinked to original sources

bioRxiv2024

Worldwide soundscape ecology patterns across realms

Abstract and keywordsO_ST_ABSAimC_ST_ABSThe urgency for remote, reliable, and scalable biodiversity monitoring amidst mounting human pressures on ecosystems has sparked worldwide interest in Passive Acoustic Monitoring (PAM), which can track life underwater and on land. However, we lack a unified methodology to report this sampling effort and a comprehensive overview of PAM coverage to gauge its potential as a global research and monitoring tool. To remediate this, we created the Worldwide Soundscapes project, a collaborative network and growing database comprising metadata from 409 datasets across all realms (terrestrial, marine, freshwater, and subterranean). LocationWorldwide, 12 200 sites, all ecosystems. Time period1991 to present. Major taxa studiedAll soniferous taxa. MethodsWe synthesise sampling coverage across spatial, temporal, and ecological scales using metadata describing sampling locations, deployment schedules, focal taxa, and recording parameters. We explore global trends in biological, anthropogenic, and geophysical sounds based on 168 recordings from twelve ecosystems across all realms. ResultsTerrestrial sampling is spatially denser (45 sites/Mkm2) than aquatic sampling (0.3 and 1.8 sites/Mkm2 in oceans and fresh water) with only two subterranean datasets. Although diel and lunar cycles are well-covered in all realms, only marine datasets (56%) comprehensively sample all seasons. Across twelve ecosystems, biological sounds show contrasting diel patterns, decline with distance from the equator and negatively correlate with anthropogenic sounds. Main conclusionsPAM can inform macroecology studies as well as global conservation and phenology syntheses, but representation can be improved by expanding terrestrial taxonomic scope, sampling coverage in the high seas and subterranean ecosystems, and spatio-temporal replication in freshwater habitats. Overall, this global PAM network holds promise to support global biodiversity research and monitoring efforts.

ecology↗

bioRxiv2019

Freshwater soundscapes: a cacophony of undescribed biological sounds now threatened by anthropogenic noise

The soundscape composition of freshwater habitats is poorly understood. Our goal was to document the occurrence of biological sounds in a large variety of freshwater habitats over a large geographic area. The underwater soundscape was sampled in freshwater habitat categorized as brook/creek, pond/lake, or river, from five major river systems in North America (Connecticut, Kennebec, Merrimack, Presumpscot, and Saco) over a five-week period in the spring of 2008. Over 7,000 sounds were measured from 2,750 minutes of recording in 173 locations, and classified into major anthropophony (airplane, boat, traffic, train and other noise) and biophony (fish air movement, also known as air passage, other fish, insect-like, bird, and other biological) sound categories. Anthropogenic noise dominated the soundscape of all habitats averaging 15 % of time per recording compared to less than 2 % for biological sounds. Anthropophony occurred in 79 % of recordings and was mainly due to traffic and boat sounds, which exhibited significant differences among habitats and between non-tidal and tidal river regions. Most biophonic sounds were from unidentified insect-like, air movement fish, and other fish sound sources that occurred in 57 % of recordings. Mean frequencies of anthropogenic noises overlapped strongly with the biophony, and comparisons of spectra suggest that insect- like and air movement sounds may be more susceptible to masking than other fish sounds. There was a significant decline in biodiversity and biophony with increasing ambient sound levels. Our poor understanding of the biophony of freshwater ecosystems, together with an apparent high temporal exposure to anthropogenic noise across all habitats, suggest a critical need for studies aimed at identification of biophonic sound sources and assessment of potential threats from anthropogenic noises.

ecology↗