Minke whales (Balaenoptera acutorostrata) respond to navy training

Abstract

Minke whales (Balaenoptera acutorostrata) were acoustically detected and localized via their boing calls using 766 h of recorded data from 24 hydrophones at the U.S. Navy's Pacific Missile Range Facility located off Kauai, Hawaii. Data were collected before, during, and after naval undersea warfare training events, which occurred in February over three consecutive years (2011-2013). Data collection in the during periods were further categorized as phase A and phase B with the latter being the only period with naval surface ship activities (e.g., frigate and destroyer maneuvers including the use of mid-frequency active sonar). Minimum minke whale densities were estimated for all data periods based upon the numbers of whales acoustically localized within the 3780 km(2) study area. The 2011 minimum densities in the study area were: 3.64 whales [confidence interval (CI) 3.31-4.01] before the training activity, 2.81 whales (CI 2.31-3.42) for phase A, 0.69 whales (CI 0.27-1.8) for phase B and 4.44 whales (CI 4.04-4.88) after. The minimum densities for the phase B periods were highly statistically significantly lower (p < 0.001) from all other periods within each year, suggesting a clear response to the phase B training. The phase A period results were mixed when compared to other non-training periods.

Marine mammals and sonar: Dose‐response studies, the risk‐disturbance hypothesis and the role of exposure context

“…Opportunistic exposure studies, utilizing passive acoustic monitoring methods, for example, are key components of long‐term monitoring studies (e.g. Henderson et al., ; Martin, Martin, Matsuyama, & Henderson, ; McCarthy et al., ; Moretti et al., ). Data from these monitoring studies should be used to detect behavioural responses and to test expectations and predictions of experimental studies (Moretti et al., ).…”

Estimation of minke whale abundance from an acoustic line transect survey of the Mariana Islands

“…) over the short periods of times used in localization and tracking individuals (Martin et al . ). A graph of the cross correlation function (used by the algorithm to estimate the time delay of signal arrival between two hydrophones) was reviewed by the data analyst to provide information about the relative errors in the bearing angle estimation (Mellinger ).…”

“…) (Martin et al . , ). The DSC is the peak frequency within a particular frequency band in the call, and is unique to individual minke whales (Martin et al .…”

“…Each boing was analyzed further by calculating the dominant signal component (DSC) values in Boinger (see bottom-left panel of Fig. 1) (Martin et al 2013(Martin et al , 2014). The DSC is the peak frequency within a particular frequency band in the call, and is unique to individual minke whales (Martin et al 2013) over the short periods of times used in localization and tracking individuals (Martin et al 2014).…”

“…1) (Martin et al 2013(Martin et al , 2014). The DSC is the peak frequency within a particular frequency band in the call, and is unique to individual minke whales (Martin et al 2013) over the short periods of times used in localization and tracking individuals (Martin et al 2014). A graph of the cross correlation function (used by the algorithm to estimate the time delay of signal arrival between two hydrophones) was reviewed by the data analyst to provide information about the relative errors in the bearing angle estimation (Mellinger 2001).…”