High-Speed Vessel Noises in West Hong Kong Waters and Their Contributions Relative to Indo-Pacific Humpback Dolphins (Sousa chinensis)

Figure 2

Ambient sounds of the four areas varying in general ship traffic and types of ships present. Bottlenose and humpback dolphin audiograms show the magnitudinal difference between vessel sounds and minimum audible levels for the dolphins. Southwest Lantau number 2 (SWL number 2) is between the Soko Islands with very little boat traffic and a Beaufort sea state (Bss) of 3. Likewise, Northwest Lantau number 1 (NWL number 1) is described as having very little boat traffic, located within the Sha Chau and Lung Kwu Chau Marine Park, recorded during a Bss of 3. West Lantau number 3 (WL number 3) is within the very busy shipping route at South Lantau Vessel Fairway with a high-speed ferry away at 702 m, Bss 3. South Lantau Vessel Fairway (SLVF) was recorded with several ferries and a shrimp trawler present during a Beaufort sea state of 0.