Soundscape of green turtle foraging habitats in Fiji, South Pacific

Elena Papale; Shritika Prakash; Shubha Singh; Aisake Batibasaga; Giuseppa Buscaino; Susanna Piovano

doi:10.1371/journal.pone.0236628

Soundscape of green turtle foraging habitats in Fiji, South Pacific

PLoS One. 2020 Aug 5;15(8):e0236628. doi: 10.1371/journal.pone.0236628. eCollection 2020.

Authors

Elena Papale^{1

2}, Shritika Prakash³, Shubha Singh³, Aisake Batibasaga⁴, Giuseppa Buscaino¹, Susanna Piovano³

Affiliations

¹ BioacousticsLab, IAS Capo Granitola, National Research Council, Torretta Granitola, Italy.
² Department of Life Science and Systems Biology, University of Torino, Torino, Italy.
³ School of Marine Studies, The University of the South Pacific, Suva, Fiji.
⁴ Ministry of Fisheries, Suva, Fiji.

Abstract

The soundscape features of the marine environment provide crucial information about ecosystem health for many species, and they are defined by the local biological, geophysical, and anthropogenic components. In this study, we investigated the soundscape at green turtle neritic foraging habitats in Fiji, South Pacific, with the aims of characterizing the contribution of each component and of comparing the levels of acoustic pressure among sites with different abundances of sea turtles. Four sites were selected at two islands, and one hydrophone was deployed at each site. Generalized additive models highlighted that sound pressure levels (SPLs) at low frequencies (125-250 Hz) were especially affected by wind conditions, while at higher frequencies (>250 Hz) SPLs were mostly influenced by fish and crustacean acoustic activity. Higher abundances of green turtles were found at sites with the highest levels of SPLs and the highest number of acoustic emissions by fishes and crustaceans but were not related to maximum seagrass and macroalgae coverage, or the highest number of fish. The selected coastal habitats have negligible anthropogenic noise, thus this study informs physiological and behavioral studies of the acoustic signatures that sea turtles might target and provides a baseline against which potential impact of soundscape changes on sea turtle spatial abundance and distribution can be evaluated.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Acoustics*
Animals
Ecosystem
Environmental Monitoring
Fiji
Fishes / physiology
Noise*
Turtles / physiology*

Grants and funding

SPi received the award from the Pacific Islands Regional Office of the United States National Oceanic and Atmospheric Administration (grant NA17NMF4540081, https://www.fisheries.noaa.gov/about/pacific-islands-regional-office), which partially funded the field activities at Yadua Island. Field activities at Makogai Island were partially supported by Ministry of Fisheries (www.fisheries.gov.fj). The funding agencies had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript, which remains entirely on the authors. However, we acknowledge that at time of this research AB was Director of Ministry of Fisheries.