To understand the extent of anthropogenic noise in the ocean, it is essential to compare the differences between modern noise environments and their pre-industrial equivalents. The Santa Barbara Channel, off the coast of Southern California, is a corridor for the transportation of goods to and from the busiest shipping ports in the Western hemisphere. Commercial ships introduce high levels of underwater noise into the marine environment. To quantify the extent of noise in the region, we modeled pre-industrial ocean noise levels, driven by wind, and modern ocean noise levels, resulting from the presence of both ships and wind. By comparing pre-industrial and modern underwater noise levels, the low-frequency (50 Hz) acoustic environment was found to be degraded by more than 15 dB. These results can be used to identify regions for noise reduction efforts, as well as to model scenarios to identify those with the greatest potential to support marine conservation efforts.

中文翻译：

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比较圣巴巴拉海峡的工业化前和现代海洋噪音水平

为了了解海洋中人为噪音的程度，有必要比较现代噪音环境与工业化前噪音环境之间的差异。圣巴巴拉海峡位于南加州海岸附近，是西半球最繁忙的航运港口之间货物运输的走廊。商船将高水平的水下噪音引入海洋环境。为了量化该地区的噪音范围，我们模拟了由风驱动的前工业化海洋噪音水平，以及由船舶和风的存在引起的现代海洋噪音水平。通过比较工业化前和现代水下噪声水平，发现低频（50 Hz）声学环境下降了 15 dB 以上。这些结果可用于确定降噪工作的区域，以及对场景进行建模，以确定最有潜力支持海洋保护工作的区域。