02122nas a2200229 4500008004100000022001400041245007300055210006900128260001600197300001000213490000700223520144400230653001701674653002601691653001501717653002201732653002201754100001701776700001801793700002701811856005401838 2020 eng d a0046-507000aSix steps towards operationalising freshwater ecoacoustic monitoring0 aSix steps towards operationalising freshwater ecoacoustic monito cFeb-01-2021 a1 - 60 v653 a

1. Applications in bioacoustics and its sister discipline ecoacoustics have increased exponentially over the last decade. However, despite knowledge about aquatic bioacoustics dating back to the times of Aristotle and a vast amount of background literature to draw upon, freshwater applications of ecoacoustics have been lagging to date.

2.In this special issue, we present nine studies that deal with underwater acoustics, plus three acoustic studies on water‐dependent birds and frogs. Topics include automatic detection of freshwater organisms by their calls, quantifying habitat change by analysing entire soundscapes, and detecting change in behaviour when organisms are exposed to noise.

3.We identify six major challenges and review progress through this special issue. Challenges include characterisation of sounds, accessibility of archived sounds as well as improving automated analysis methods. Study design considerations include characterisation analysis challenges of spatial and temporal variation. The final key challenge is the so far largely understudied link between ecological condition and underwater sound.

4.We hope that this special issue will raise awareness about underwater soundscapes as a survey tool. With a diverse array of field and analysis tools, this issue can act as a manual for future monitoring applications that will hopefully foster further advances in the field.

10aecoacoustics10aEcological Monitoring10afreshwater10apassive acoustics10aunderwater sounds1 aLinke, Simon1 aGifford, Toby1 aDesjonquères, Camille uhttps://onlinelibrary.wiley.com/toc/13652427/65/102781nas a2200181 4500008004100000245010000041210006900141520217000210653002102380653001702401653002302418653002102441653002202462653002202484100001902506700001302525856006102538 2019 eng d00aSource separation in ecoacoustics: A roadmap towards versatile soundscape information retrieval0 aSource separation in ecoacoustics A roadmap towards versatile so3 a

A comprehensive assessment of ecosystem dynamics requires the monitoring of biological, physical and social changes. Changes that cannot be observed visually may be trackable acoustically through soundscape analysis. Soundscapes vary greatly depending on geophysical events, biodiversity and human activities. However, retrieving source‐specific information from geophony, biophony and anthropophony remains a challenging task, due to interference by simultaneous sound sources. Audio source separation is a technique that aims to recover individual sound sources when only mixtures are accessible. Here, we review techniques of monoaural audio source separation with the fundamental theories and assumptions behind them. Depending on the availability of prior information about the source signals, the task can be approached as a blind source separation or a model‐based source separation. Most blind source separation techniques depend on assumptions about the behaviour of the source signals, and their performance may deteriorate when the assumptions fail. Model‐based techniques generally do not require specific assumptions, and the models are directly learned from labelled data. With the recent advances of deep learning, the model‐based techniques can yield state‐of‐the‐art separation performance, accordingly facilitate content‐based audio information retrieval. Source separation techniques have been adopted in several ecoacoustic applications to evaluate the contributions from biodiversity and anthropogenic disturbance to soundscape dynamics. They can also be employed as nonlinear filters to improve the recognition of bioacoustic signals. To effectively retrieve ecological information from soundscapes, source separation is a crucial tool. We believe that the future integrations of ecological hypotheses and deep learning can realize a high‐performance source separation for ecoacoustics, and accordingly improve soundscape‐based ecosystem monitoring. Therefore, we outline a roadmap for applying source separation to assist in soundscape information retrieval and hope to promote cross‐disciplinary collaboration.

10aacoustic habitat10abiodiversity10aecosystem dynamics10amachine learning10apassive acoustics10aSignal processing1 aLin, Tzu‐Hao1 aTsao, Yu uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/rse2.14101785nas a2200217 4500008004100000245012800041210006900169520098500238653002201223653001201245653001701257653003401274653001801308653001501326653000801341653002201349653001601371100002001387700002401407856013601431 2019 eng d00aAcoustically estimated size distribution of sperm whales ( Physeter macrocephalus) off the east coast of New Zealand0 aAcoustically estimated size distribution of sperm whales iPhyset3 a

The length-frequency distribution of sperm whales (Physeter macrocephalus) was studied on the east coast of NZ using passive acoustic recorders moored offshore of Kaikoura, Cape Palliser and Castlepoint. Sperm whale’s echolocation signals are unique among odontocete species. Their clicks are composed by multiple pulses resulting from the sound transmission within the whale head. The total length of the whales can be estimated by measuring the time delay between these pulses. A total of 997 length measurements were obtained from click trains using cepstral analysis (mean = 14.6 m; min = 9.6 m; max = 18.3 m; std = 1 m). The size-frequency distributions at all three locations were similar, although animals smaller than 12 m were not present offshore of Kaikoura. Animals of various sizes appeared to be present all year round, with no apparent seasonality in the occurrence of any size class.

10acepstral analysis10aceptrum10aecholocation10alength-frequency distribution10amarine mammal10aodontocete10aPAM10apassive acoustics10asperm whale1 aGiorli, Giacomo1 aGoetz, Kimberly, T. uhttps://www.tandfonline.com/doi/full/10.1080/00288330.2019.1679843https://www.tandfonline.com/doi/pdf/10.1080/00288330.2019.167984302099nas a2200241 4500008004100000245013800041210006900179260001600248520131100264653001701575653002201592653001601614653002001630653001101650653002201661653002201683653002201705100002401727700002201751700001901773700002201792856004301814 2018 eng d00aAcoustic monitoring reveals the times and tides of harbor porpoise (Phocoena phocoena) distribution off central Oregon, U.S.A.0 aAcoustic monitoring reveals the times and tides of harbor porpoi cJan-10-20203 a

Harbor porpoises (Phocoena phocoena) are commonly observed in Oregon’s nearshore marine environment yet knowledge of their eco- system use and behavior remains limited, generating concerns for potential impacts on this species from future coastal development. Pas- sive acoustic monitoring was used to investigate spatial and temporal variations in the presence and foraging activity of harbor porpoises off the Oregon coast from May through October 2014. Digital monitoring devices (DMONs) were deployed to record acoustic data (320 kHz sam- ple rate) in two neighboring but bathymetrically different locations off the Oregon coast: (1) a site on the 30 m isobath in close proximity (<50 m) to a rocky reef, and (2) a site on the 60 m isobath in an open sandy environment. Data were analyzed with respect to two dynamic cyclic variables: diel and tidal phase. Porpoise presence at the rocky reef site was aligned with the ebb phase of the tidal forcing, while, har- bor porpoise presence and foraging at the offshore, sandy bottom site was associated with night-time foraging. The spatial and temporal pat- terns identified in this study suggest harbor porpoise habitat use is modulated by specific environmental conditions particular to each site that maximize foraging efficiency.

10adistribution10aforaging behavior10ahabitat use10aharbor porpoise10aOregon10apassive acoustics10aPhocoena phocoena10atemporal patterns1 aHoldman, Amanda, K.1 aHaxel, Joseph, H.1 aKlinck, Holger1 aTorres, Leigh, G. uhttp://doi.wiley.com/10.1111/mms.1253702118nas a2200289 4500008004100000022001300041245018500054210006900239260001600308300001200324490000800336520098500344653001701329653001201346653001201358653002001370653001201390653002001402653002201422100003001444700003201474700002001506700002501526700002701551700001701578856023301595 2019 eng d a0964569100aRecreational boat traffic effects on fish assemblages: First evidence of detrimental consequences at regulated mooring zones in sensitive marine areas detected by passive acoustics0 aRecreational boat traffic effects on fish assemblages First evid cJan-02-2019 a22 - 340 v1683 a

We assess the impact of recreational boat traffic on sensitive habitats in the Western Mediterranean using passive acoustics. We compared underwater sounds in three regulated mooring locations vs a pristine location; and temporal differences in the pristine location vs the nearest mooring between high and low touristic seasons. We measured the number of pulses/minute, fish pulse patterns, and percentage of boat noise occurrence and its relative average power level. At the pristine location, the call rates and their complexity were significantly higher and the motorboat noise was significantly lower. The temporal trend of biophonic sounds decreased significantly in the pristine location. In contrast, in the mooring sites, the motorboat noise decreased significantly and the fish calls remained at low levels in both seasons. In conclusion, motorboat noise negatively affects the complexity of the fish assemblages but could be conditioned to their historic uses.

10abioacoustics10aCroaker10aDrummer10aFish assemblage10aMooring10aMotorboat noise10apassive acoustics1 aCorrea, José, Miguel Gon1 aSempere, Just-Tomás, Bayle1 aJuanes, Francis1 aRountree, Rodney, A.1 aRuíz, Juan, Francisco1 aRamis, Jaime uhttps://linkinghub.elsevier.com/retrieve/pii/S0964569118301972https://api.elsevier.com/content/article/PII:S0964569118301972?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0964569118301972?httpAccept=text/plain02098nas a2200229 4500008004100000245010100041210006900142260001600211520135800227653003101585653002501616653002001641653002001661653001601681653001201697653002201709100002301731700002401754700001901778700002801797856004301825 2017 eng d00aEstimation of minke whale abundance from an acoustic line transect survey of the Mariana Islands0 aEstimation of minke whale abundance from an acoustic line transe cJan-03-20173 a

The minke whale is one of the most abundant species of baleen whales worldwide, yet is rarely sighted in subtropical waters. In the North Pacific, they produce a dis- tinctive sound known as the “boing,” which can be used to acoustically localize indi- viduals. A vessel-based survey using both visual and passive acoustic monitoring was conducted during the spring of 2007 in a large (616,000 km 2 ) study area encom- passing the Mariana Islands. We applied line transect methods to data collected from a towed hydrophone array to estimate the abundance of calling minke whales in our study area. No minke whales were sighted, but there were hundreds of acoustic detections of boings. Computer algorithms were developed to localize calling minke whales from acoustic recordings, resulting in over 30 independent localizations, a six-fold increase over those estimated during the survey. The two best estimates of abundance of calling minke whales were determined to be 80 and 91 animals (0.13 and 0.15 animals per 1,000 km2, respectively; CV = 34%). These are the first den- sity and abundance estimates for calling minke whales using towed hydrophone array surveys, and the first estimates for this species in the Mariana Islands region. These are considered minimum estimates of the true number of minke whales in the study area.

10aBalaenoptera acutorostrata10adensity esti- mation10aMariana Islands10amarine mammals.10aminke whale10aPacific10apassive acoustics1 aNorris, Thomas, F.1 aDunleavy, Kerry, J.1 aYack, Tina, M.1 aFerguson, Elizabeth, L. uhttp://doi.wiley.com/10.1111/mms.12397