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.
Subject(s)
Acoustics , Echolocation , Environmental Monitoring/methods , Military Personnel , Minke Whale/physiology , Noise, Transportation/adverse effects , Ships , Vocalization, Animal , Animals , Echolocation/classification , Minke Whale/classification , Minke Whale/psychology , Motion , Population Density , Signal Processing, Computer-Assisted , Sound , Sound Spectrography , Species Specificity , Time Factors , Vocalization, Animal/classificationABSTRACT
BACKGROUND: Whales have captivated the human imagination for millennia. These incredible cetaceans are the only mammals that have adapted to life in the open oceans and have been a source of human food, fuel and tools around the globe. The transition from land to water has led to various aquatic specializations related to hairless skin and ability to regulate their body temperature in cold water. RESULTS: We present four common minke whale (Balaenoptera acutorostrata) genomes with depth of ×13 ~ ×17 coverage and perform resequencing technology without a reference sequence. Our results indicated the time to the most recent common ancestors of common minke whales to be about 2.3574 (95% HPD, 1.1521 - 3.9212) million years ago. Further, we found that genes associated with epilation and tooth-development showed signatures of positive selection, supporting the morphological uniqueness of whales. CONCLUSIONS: This whole-genome sequencing offers a chance to better understand the evolutionary journey of one of the largest mammals on earth.