Acoustic assessment of SIMRAD EK60 high frequency echo sounder signals (120 & 200 kHz) in the context of marine mammal monitoring

The use of active high frequency echo sounders for commercial activities and marine research has been increasing in recent years. Compared to other anthropogenic noise sources, high frequency echo sounders have received little attention in terms of their potential impacts on marine life. However, while these devices typically operate at centre frequencies outside the hearing range of most marine species, recent work has demonstrated that they may produce unintended energy at lower frequencies. These lower frequencies may extend into the audible range for several species of marine mammals and have the potential to affect their behaviour (Deng et al. 2014). Given the theoretical detectability of these lower frequencies by marine mammals, both signal types have the potential to elicit behavioural responses towards them. This should be considered in environmental impact assessments of activities using these devices and when planning marine mammal monitoring studies alongside ecosystem studies using active acoustic sonar systems

A framework to predict, validate and review the acoustic footprints of operating tidal turbines [abstract]

A framework to predict, validate and review the acoustic footprints of operating tidal turbines [abstract

Sonar signal analysis: Biological consequences of out-of-band acoustic signals from active sonar systems [conference presentation]

Sonar signal analysis: Biological consequences of out-of-band acoustic signals from active sonar systems [conference presentation

Audibility of SIMRAD EK60 high frequency echo sounder signals to marine mammals [Abstract]

Conference abstrac

Exploring influences of lower-frequency acoustic deterrent devices (ADDs) on harbour porpoise in Scottish coastal waters [Abstract]

Conference abstrac

The acoustic tracks of two singing humpback whales over a 5 h time period.

<p>Song occurred simultaneously for 1.5 h. Blue points indicate the locations of each individual when singing alone; red points indicate the locations of singers while both songs were recorded simultaneously. Times (in EST) when each song session began and ended are indicated on both tracks.</p

Map of the study location in the northwest Atlantic ocean.

<p>The inset shows Stellwagen Bank National Marine Sanctuary outlined in white (A). Black dots indicate the locations of bottom-mounted Marine Autonomous Recording Units deployed from (B) 28 March to 28 May 2009, and (C) 2 October to 15 December 2009. Bathymetry map provided by M. Thompson, Stellwagen Bank National Marine Sanctuary.</p

Comparison of summary statistics for the acoustic tracks of singing humpback whales recorded during the spring and fall seasons.

<p>Spring tracks were recorded between 01 April 2009 and 03 May 2009; fall tracks were recorded between 25 October 2009 and 26 November 2009. Mean, standard deviation (SD), and range (minimum & maximum) are reported for measured track parameters within each season.</p

Correlation matrix with pairwise comparisons of track parameters.

<p>Parameters are labeled along the diagonal: dist  =  distance traveled (km), dur  =  duration (h), speed  =  average speed (km/h), disp  =  net displacement (km), SI  =  straightness index (unitless). Scatterplots are shown in the lower left triangle below the diagonal; Spearman's rank correlation coefficients are shown in the upper right triangle above the diagonal. Red asterisks indicate significance level: ***<0.001, **<0.01, *<0.05.</p

Occurrence of humpback whale song within Stellwagen Bank National Marine Sanctuary throughout 2009.

<p>Recordings were made across 12 months, and song occurrence is represented as the number of hours per day during which song was detected.</p