The Effect of Noise on Marine Mammals provides a comprehensive summary of underwater noise sources. However, one of the main reasons for this review is to help in the assessment of the likely impact of noise on marine animals.

Man made noise underwater can cover a broad range of frequencies, and the way in which a marine mammal responds to a given level will vary, depending on the hearing threshold of the species. The image below illustrates the hearing thresholds of fish and marine mammals.

Hearing thresholds

Concerns over the environmental effects of noise on marine mammals prompted Subacoustech to develop and propose the dBht(Species) metric as a formal method for evaluating the effects of underwater noise [1]. Using this metric, it is possible to estimate the impact that a broadband noise source will have upon a specific species.

For further details regarding the dBht(Species) metric, consult the Subacoustech website.

  1. Nedwell J R, Turnpenny A W H (1998)
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