Whale Song in Submarine Fiction (original) (raw)

Impacts of Navy Sonar on Whales and Dolphins: Now beyond a Smoking Gun

The risks military sonar poses to cetaceans received international attention with a highly-publicized mass stranding of Cuvier’s beaked whales (Ziphius cavirostris), Blainville’s beaked whales (Mesoplodon densirostris), and northern minke whales (Balaenoptera acutorostrata) in the Bahamas in 2000. This was the first time that the US Government determined a stranding to be the result of mid-frequency active sonar use. Subsequently attention has been drawn to other mass strandings coincident with naval exercises, including events preceding the 2000 mass stranding. The list of species for which mass strandings have been linked to naval exercises has also increased to include other beaked whales, dwarf and pygmy sperm whales (Kogia spp.), pilot whales (Globicephala spp.), several dolphin species (Stenella sp. and Delphinus delphis), and harbor porpoises (Phocoena phocoena). In particular, there have been several mass strandings in the northern Indian Ocean coincident with naval exercises—including one of the largest (200–250 dolphins)—which have received little attention. Changes in beaked whale behavior, including evasive maneuvering, have been recorded at received levels below <100 dB re 1μPa (rms) and mass stranding may occur at received levels potentially as low as 150–170 dB re 1μPa. There is strong scientific evidence to suggest that a wide range of whale, dolphin and porpoise species can also be impacted by sound produced during military activities, with significant effects occurring at received levels lower than previously predicted. Although there are many stranding events that have occurred coincident with the presence of naval vessels or exercises, it is important to emphasize that even the absence of strandings in a region does not equate to an absence of deaths, i.e., absence of evidence does not mean evidence of absence. Strandings may be undetected, or be unlikely to be observed because of a lack of search effort or due to coastal topography or characteristics. There may also be “hidden” impacts of sonar and exercises not readily observable (e.g., stress responses). Due to the level of uncertainty related to this issue, ongoing baseline monitoring for cetaceans in exercise areas is important and managers should take a precautionary approach to mitigating impacts and protecting species.

Acoustic Properties of Humpback Whale Songs

The Journal of the …, 2006

A vertical array of five hydrophones was used to measure the acoustic field in the vertical plane of singing humpback whales. Once a singer was located, two swimmers with snorkel gear were deployed to determine the orientation of the whale and position the boat so that the array ...

Advances in research on the impacts of anti-submarine sonar on beaked whales

Proceedings of the Royal Society B: Biological Sciences, 2019

Mass stranding events (MSEs) of beaked whales (BWs) were extremely rare prior to the 1960s but increased markedly after the development of naval mid-frequency active sonar (MFAS). The temporal and spatial associations between atypical BW MSEs and naval exercises were first observed in the Canary Islands, Spain, in the mid-1980s. Further research on BWs stranded in association with naval exercises demonstrated pathological findings consistent with decompression sickness (DCS). A 2004 ban on MFASs around the Canary Islands successfully prevented additional BW MSEs in the region, but atypical MSEs have continued in other places of the world, especially in the Mediterranean Sea, with examined individuals showing DCS. A workshop held in Fuerteventura, Canary Islands, in September 2017 reviewed current knowledge on BW atypical MSEs associated with MFAS. Our review suggests that the effects of MFAS on BWs vary among individuals or populations, and predisposing factors may contribute to ind...

Underwater audiogram of a false killer whale (Pseudorca crassidens)

The Journal of the Acoustical Society of America, 1988

Underwater audiograms are available for only a few odontocete species. A false killer whale (Pseudorca crassidens) was trained at Sea Life Park in Oahu, Hawaii for an underwater hearing test using a go/no-go response paradigm. Over a 6-month period, auditory thresholds from 2-115 kHz were measured using an up/down staircase psychometric technique. The resulting audiogram showed hearing sensitivities below 64 kHz similar to those of belugas (Delphinapterus leucas) and Atlantic bottlenosed dolphins (Tursiops truncatus). Above 64 kHz, this Pseudorca had a rapid decrease in sensitivity of about 150 dB per octave. A similar decrease in sensitivity occurs at 32 kHz in the killer whale, at 50 kHz in the Amazon River dolphin, at 120 kHz in the beluga, at 140 kHz in the bottlenosed dolphin, and at 140 kHz in the harbor porpoise. The most sensitive range of hearing was from 16-64 kHz (a range of 10 dB from the maximum sensitivity). This range corresponds with the peak frequency of echolocatio...