{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,6]],"date-time":"2025-12-06T17:09:42Z","timestamp":1765040982467,"version":"build-2065373602"},"reference-count":64,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2019,10,6]],"date-time":"2019-10-06T00:00:00Z","timestamp":1570320000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004663","name":"Ministry of Science and Technology, Taiwan","doi-asserted-by":"publisher","award":["103-3113-E-002-002 -CC2","104-3113-E-002-002","105-3113-E-002-002 -CC2","106-2811-E-002-077"],"award-info":[{"award-number":["103-3113-E-002-002 -CC2","104-3113-E-002-002","105-3113-E-002-002 -CC2","106-2811-E-002-077"]}],"id":[{"id":"10.13039\/501100004663","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Automated acoustic indices to infer biological sounds from marine recordings have produced mixed levels of success. The use of such indices in complex marine environments, dominated by several anthropogenic and geophonic sources, have yet to be understood fully. In this study, we introduce a noise resilient method based on complexity-entropy (hereafter named C-H) for the detection of biophonic sounds originating from fish choruses. The C-H method was tested on data collected in Changhua and Miaoli (Taiwan) during the spring in both 2016 and 2017. Miaoli was exposed to continual shipping activity, which led to an increase of ~10 dB in low frequency ambient noise levels (5\u2013500 Hz). The acoustic dataset was successively analyzed via the acoustic complexity index, the acoustic diversity index and the bioacoustic index. The C-H method was found to be strongly correlated with fish chorusing (Pearson correlation: rH &lt; \u22120.9; rC &gt; 0.89), and robust to noise originating from shipping activity or natural sources, such as wind and tides (rH and rC were between 0.22 and \u22120.19). Other indices produced lower or null correlations with fish chorusing due to missed identification of the choruses or sensitivity to other sound sources. In contrast to most acoustic indices, the C-H method does not require a prior setting of frequency and amplitude thresholds, and is therefore, more user friendly to untrained technicians. We conclude that the use of the C-H method has potential implications in the efficient detection of fish choruses for management or conservation purposes and could help with overcoming the limitations of acoustic indices in noisy marine environments.<\/jats:p>","DOI":"10.3390\/e21100977","type":"journal-article","created":{"date-parts":[[2019,10,7]],"date-time":"2019-10-07T03:34:01Z","timestamp":1570419241000},"page":"977","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["A Complexity-Entropy Based Approach for the Detection of Fish Choruses"],"prefix":"10.3390","volume":"21","author":[{"given":"Shashidhar","family":"Siddagangaiah","sequence":"first","affiliation":[{"name":"Underwater Acoustic Laboratory, Department of Engineering Sciences and Ocean Engineering, National Taiwan University, Taipei 106, Taiwan"}]},{"given":"Chi-Fang","family":"Chen","sequence":"additional","affiliation":[{"name":"Underwater Acoustic Laboratory, Department of Engineering Sciences and Ocean Engineering, National Taiwan University, Taipei 106, Taiwan"}]},{"given":"Wei-Chun","family":"Hu","sequence":"additional","affiliation":[{"name":"Underwater Acoustic Laboratory, Department of Engineering Sciences and Ocean Engineering, National Taiwan University, Taipei 106, Taiwan"}]},{"given":"Nadia","family":"Pieretti","sequence":"additional","affiliation":[{"name":"Department of Life and Environmental Science, Polytechnic University of Marche, 60131 Ancona, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2019,10,6]]},"reference":[{"key":"ref_1","unstructured":"Marine Mammal Commission (MMC) (2005). Advisory Committee on Acoustic Impacts on Marine Mammals."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"United Nations General Assembly (2014). Resolution \u201cOceans and the Law of the Sea\u201d.","DOI":"10.18356\/3ff6d0d6-en"},{"key":"ref_3","unstructured":"International Union for Conservation of Nature (2004). The International Union for Conservation of Nature and Natural Resources (Iucn), Undersea Noise Pollution."},{"key":"ref_4","unstructured":"Board, O.S., and Council, N.R. (2005). Marine Mammal Populations and Ocean Noise: Determining When Noise Causes Biologically Significant Effects, National Academies Press."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1038\/35016148","article-title":"Whale songs lengthen in response to sonar","volume":"405","author":"Miller","year":"2000","journal-title":"Nature"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/j.anbehav.2013.12.029","article-title":"Acoustic noise reduces foraging success in two sympatric fish species via different mechanisms","volume":"89","author":"Voellmy","year":"2014","journal-title":"Anim. Behav."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Voellmy, I.K., Purser, J., Simpson, S.D., and Radford, A.N. (2014). Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0102946"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1121\/1.1461915","article-title":"Ocean ambient sound: Comparing the 1960s with the 1990s for a receiver off the california coast","volume":"3","author":"Andrew","year":"2002","journal-title":"Acoust. Res. Lett. Online"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"20160042","DOI":"10.1098\/rstb.2016.0042","article-title":"Adaptive capabilities and fitness consequences associated with pollution exposure in fish","volume":"372","author":"Hamilton","year":"2017","journal-title":"Philos. Trans. R. Soc. B Biol. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"20160839","DOI":"10.1098\/rspb.2016.0839","article-title":"Aquatic noise pollution: Implications for individuals, populations, and ecosystems","volume":"283","author":"Kunc","year":"2016","journal-title":"Proc. R. Soc. B Biol. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"36","DOI":"10.5670\/oceanog.2007.03","article-title":"An overview of fixed passive acoustic observation methods for cetaceans","volume":"20","author":"Mellinger","year":"2007","journal-title":"Oceanography"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"21","DOI":"10.3354\/meps08123","article-title":"Management and research applications of real-time and archival passive acoustic sensors over varying temporal and spatial scales","volume":"395","author":"Clark","year":"2009","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Farina, A., and Gage, S.H. (2017). Biodiversity assessment and environmental monitoring in freshwater and marine biomes using ecoacoustics. Ecoacoustics. The Ecological Role of Sounds, Wiley.","DOI":"10.1002\/9781119230724"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1007\/s00338-012-1007-8","article-title":"Soundscapes from a tropical eastern pacific reef and a caribbean sea reef","volume":"32","author":"Staaterman","year":"2013","journal-title":"Coral Reefs"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Au, W.W., and Lammers, M.O. (2016). Listening in the Ocean, Springer.","DOI":"10.1007\/978-1-4939-3176-7"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.ecolind.2017.07.064","article-title":"Biases of acoustic indices measuring biodiversity in urban areas","volume":"83","author":"Fairbrass","year":"2017","journal-title":"Ecol. Indic."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1111\/j.1749-4877.2008.00132.x","article-title":"Soundscapes and the sense of hearing of fishes","volume":"4","author":"Fay","year":"2009","journal-title":"Integr. Zool."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1007\/s12304-015-9248-x","article-title":"Ecoacoustics: The ecological investigation and interpretation of environmental sound","volume":"8","author":"Sueur","year":"2015","journal-title":"Biosemiotics"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.ecoinf.2013.11.007","article-title":"The use of acoustic indices to determine avian species richness in audio-recordings of the environment","volume":"21","author":"Towsey","year":"2014","journal-title":"Ecol. Inform."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Farina, A., and Gage, S.H. (2017). Ecoacoustics: The Ecological Role of Sounds, John Wiley & Sons.","DOI":"10.1002\/9781119230724"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.ecolind.2017.07.011","article-title":"Marine soundscape as an additional biodiversity monitoring tool: A case study from the adriatic sea (mediterranean sea)","volume":"83","author":"Pieretti","year":"2017","journal-title":"Ecol. Indic."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1016\/j.jembe.2013.05.012","article-title":"A comparison of inshore marine soundscapes","volume":"446","author":"McWilliam","year":"2013","journal-title":"J. Exp. Mar. Biol. Ecol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"93","DOI":"10.3354\/meps11382","article-title":"Coral reef species assemblages are associated with ambient soundscapes","volume":"533","author":"Kaplan","year":"2015","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/j.ecoinf.2013.11.003","article-title":"Assessing marine ecosystem acoustic diversity across ocean basins","volume":"21","author":"Parks","year":"2014","journal-title":"Ecol. Inform."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e1393","DOI":"10.7717\/peerj.1393","article-title":"First description of underwater acoustic diversity in three temperate ponds","volume":"3","author":"Desjonqueres","year":"2015","journal-title":"PeerJ"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"455","DOI":"10.5343\/bms.2016.1043","article-title":"Nocturnal patterns in fish chorusing off the coasts of georgia and eastern florida","volume":"93","author":"Rice","year":"2017","journal-title":"Bull. Mar. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Parsons, M., Erbe, C., McCauley, R., McWilliam, J., Marley, S., Gavrilov, A., and Parnum, I. (2016, January 10\u201316). Long-term monitoring of soundscapes and deciphering a usable index: Examples of fish choruses from Australia. Proceedings of the Meetings on Acoustics 4ENAL, Dublin, Ireland.","DOI":"10.1121\/2.0000286"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"772","DOI":"10.3813\/AAA.918757","article-title":"Acoustic indices for biodiversity assessment and landscape investigation","volume":"100","author":"Sueur","year":"2014","journal-title":"Acta Acust. United Acust."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"868","DOI":"10.1016\/j.ecolind.2010.11.005","article-title":"A new methodology to infer the singing activity of an avian community: The acoustic complexity index (aci)","volume":"11","author":"Pieretti","year":"2011","journal-title":"Ecol. Indic."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1233","DOI":"10.1007\/s10980-011-9636-9","article-title":"A primer of acoustic analysis for landscape ecologists","volume":"26","author":"Pijanowski","year":"2011","journal-title":"Landsc. Ecol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1525\/bio.2011.61.3.6","article-title":"Soundscape ecology: The science of sound in the landscape","volume":"61","author":"Pijanowski","year":"2011","journal-title":"BioScience"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2137","DOI":"10.1890\/07-0004.1","article-title":"Multi-trophic invasion resistance in hawaii: Bioacoustics, field surveys, and airborne remote sensing","volume":"17","author":"Boelman","year":"2007","journal-title":"Ecol. Appl."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"34230","DOI":"10.1038\/srep34230","article-title":"Temporal patterns in the soundscape of the shallow waters of a mediterranean marine protected area","volume":"6","author":"Buscaino","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1111\/2041-210X.12527","article-title":"Ecoacoustic indices as proxies for biodiversity on temperate reefs","volume":"7","author":"Harris","year":"2016","journal-title":"Methods Ecol. Evol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.biosystems.2016.05.011","article-title":"The acoustic communities: Definition, description and ecological role","volume":"147","author":"Farina","year":"2016","journal-title":"Biosystems"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Lindseth, A., and Lobel, P. (2018). Underwater soundscape monitoring and fish bioacoustics: A review. Fishes, 3.","DOI":"10.3390\/fishes3030036"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1553","DOI":"10.3390\/e14081553","article-title":"Permutation entropy and its main biomedical and econophysics applications: A review","volume":"14","author":"Zanin","year":"2012","journal-title":"Entropy"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/S0375-9601(97)00855-4","article-title":"Measures of statistical complexity: Why?","volume":"238","author":"Feldman","year":"1998","journal-title":"Phys. Lett. A"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"103117","DOI":"10.1063\/1.4932561","article-title":"On the dynamics of ocean ambient noise: Two decades later","volume":"25","author":"Siddagangaiah","year":"2015","journal-title":"Chaos Interdiscip. J. Nonlinear Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"174102","DOI":"10.1103\/PhysRevLett.88.174102","article-title":"Permutation entropy: A natural complexity measure for time series","volume":"88","author":"Bandt","year":"2002","journal-title":"Phys. Rev. Lett."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"154102","DOI":"10.1103\/PhysRevLett.99.154102","article-title":"Distinguishing noise from chaos","volume":"99","author":"Rosso","year":"2007","journal-title":"Phys. Rev. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"062106","DOI":"10.1103\/PhysRevE.95.062106","article-title":"Characterizing time series via complexity-entropy curves","volume":"95","author":"Ribeiro","year":"2017","journal-title":"Phys. Rev. E"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Siddagangaiah, S., Li, Y., Guo, X., Chen, X., Zhang, Q., Yang, K., and Yang, Y. (2016). A complexity-based approach for the detection of weak signals in ocean ambient noise. Entropy, 18.","DOI":"10.3390\/e18030101"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2421","DOI":"10.1016\/j.physa.2011.12.009","article-title":"Complexity\u2013entropy causality plane: A useful approach for distinguishing songs","volume":"391","author":"Ribeiro","year":"2012","journal-title":"Phys. A Stat. Mech. Appl."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1007\/s00227-018-3344-9","article-title":"Long-term study on seasonal changes in floristic composition and structure of marine macroalgal communities along the coast of northern taiwan, southern east china sea","volume":"165","author":"Lin","year":"2018","journal-title":"Mar. Biol."},{"key":"ref_46","first-page":"325","article-title":"Characterization of sounds of the blackspotted croaker protonibea diacanthus (sciaenidae) and localization of its spawning sites in estuarine coastal waters of taiwan","volume":"48","author":"Mok","year":"2009","journal-title":"Zool. Stud."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"586","DOI":"10.1121\/1.2384844","article-title":"Sound characteristics of big-snout croaker, johnius macrorhynus (sciaenidae)","volume":"121","author":"Lin","year":"2007","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1515\/MAMM.2007.032","article-title":"Distribution, abundance and conservation status of the eastern taiwan strait population of indo-pacific humpback dolphins, sousa chinensis","volume":"71","author":"Wang","year":"2007","journal-title":"Mammalia"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/bs.amb.2015.04.002","article-title":"Re-assessment of the conservation status of the indo-pacific humpback dolphin (sousa chinensis) using the iucn red list criteria","volume":"Volume 73","author":"Jefferson","year":"2016","journal-title":"Advances in Marine Biology"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1109\/JQE.2010.2078799","article-title":"Time scales of a chaotic semiconductor laser with optical feedback under the lens of a permutation information analysis","volume":"47","author":"Soriano","year":"2011","journal-title":"IEEE J. Quantum Electron."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"043106","DOI":"10.1063\/1.2991106","article-title":"The organization of intrinsic computation: Complexity-entropy diagrams and the diversity of natural information processing","volume":"18","author":"Feldman","year":"2008","journal-title":"Chaos Interdiscip. J. Nonlinear Sci."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/j.physa.2003.11.005","article-title":"Intensive entropic non-triviality measure","volume":"334","author":"Lamberti","year":"2004","journal-title":"Phys. A Stat. Mech. Appl."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1016\/0375-9601(95)00867-5","article-title":"A statistical measure of complexity","volume":"209","author":"Mancini","year":"1995","journal-title":"Phys. Lett. A"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"041905","DOI":"10.1103\/PhysRevE.65.041905","article-title":"Analysis of symbolic sequences using the jensen-shannon divergence","volume":"65","author":"Grosse","year":"2002","journal-title":"Phys. Rev. E"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/j.physa.2005.11.053","article-title":"Generalized statistical complexity measures: Geometrical and analytical properties","volume":"369","author":"Martin","year":"2006","journal-title":"Phys. A Stat. Mech. Appl."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"3729","DOI":"10.1142\/S0218127407019652","article-title":"Parameter selection for permutation entropy measurements","volume":"17","author":"Staniek","year":"2007","journal-title":"Int. J. Bifurc. Chaos"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1891","DOI":"10.1016\/j.physa.2010.01.007","article-title":"Complexity-entropy causality plane: A useful approach to quantify the stock market inefficiency","volume":"389","author":"Zunino","year":"2010","journal-title":"Phys. A Stat. Mech. Appl."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Sippel, S., Lange, H., and Gans, F. (2019, October 17). Statcomp: Statistical Complexity and Information Measures for Time Series Analysis; R Package Version: 2016. Available online: https:\/\/www.rdocumentation.org\/packages\/statcomp\/versions\/0.0.1.1000.","DOI":"10.32614\/CRAN.package.statcomp"},{"key":"ref_59","unstructured":"R Core Team (2016). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing."},{"key":"ref_60","unstructured":"Villanueva-Rivera, L., and Pijanowski, B. (2019, October 17). Soundecology: Soundscape Ecology; R Package Version: 2016. Available online: http:\/\/cran.nexr.com\/web\/packages\/soundecology\/index.html."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1111\/2041-210X.12330","article-title":"Measuring acoustic habitats","volume":"6","author":"Merchant","year":"2015","journal-title":"Methods Ecol. Evol."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/S0034-4257(97)00083-7","article-title":"Selecting and interpreting measures of thematic classification accuracy","volume":"62","author":"Stehman","year":"1997","journal-title":"Remote Sens. Environ."},{"key":"ref_63","doi-asserted-by":"crossref","unstructured":"Farina, A. (2013). Soundscape Ecology: Principles, Patterns, Methods and Applications, Springer.","DOI":"10.1007\/978-94-007-7374-5"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"EL278","DOI":"10.1121\/1.5034169","article-title":"Comparison of passive acoustic soniferous fish monitoring with supervised and unsupervised approaches","volume":"143","author":"Lin","year":"2018","journal-title":"J. Acoust. Soc. Am."}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/21\/10\/977\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:27:54Z","timestamp":1760189274000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/21\/10\/977"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,10,6]]},"references-count":64,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2019,10]]}},"alternative-id":["e21100977"],"URL":"https:\/\/doi.org\/10.3390\/e21100977","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2019,10,6]]}}}