Department of Biology, Swenson Science Building, University of Minnesota Duluth, MN, 55812, USA.
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI, 54603, USA.
J Environ Manage. 2021 Oct 15;296:112720. doi: 10.1016/j.jenvman.2021.112720. Epub 2021 May 21.
Vessel sound is now globally recognized as a significant and pervasive pollutant to aquatic life. However, compared to marine environments, there is a paucity of data on sound emitted by vessel activity in freshwater habitats. The Upper Mississippi River (UMR) is home to a diverse array of aquatic life as well as being a key route for barge transportation with 29 locks and dams. In this study, passive acoustic monitoring was conducted at Lock and Dam 19 near Keokuk, Iowa, on the UMR between 20 June - August 28, 2019 to coincide with peak navigation use. There was a significant increase in median sound pressure level (SPL; 50-12,000 Hz) recorded during vessel passages (123 dB re. 1μPa for recreational vessels and 137 dB re. 1μPa for commercial vessels) compared to median background levels (111 dB re. 1μPa). Results provide information on the ambient soundscape at a navigation lock, providing a baseline essential for future studies gauging the effect of anthropogenic sound on aquatic life. Lock 19 has also been identified as a potential site for acoustic deterrent deployment to prevent invasive fish movements. The results of this study can help determine the sound level or frequency deterrents would need to emit, to avoid those currently produced during vessel passage.
船舶噪音现已被全球公认为对水生生物的一种重大且普遍的污染物。然而，与海洋环境相比，有关船舶活动在淡水生境中产生的噪音的数据却很少。密西西比河上游（UMR）是多种水生生物的家园，也是驳船运输的重要通道，拥有 29 个船闸和水坝。本研究于 2019 年 6 月 20 日至 8 月 28 日在爱荷华州基奥卡克附近的 19 号船闸和水坝进行了被动声学监测，与高峰航行使用时间相吻合。与背景中位数（111dB re.1μPa）相比，船舶通过时记录的中位数声压级（SPL；50-12,000Hz）有显著增加（休闲船为 123dB re.1μPa，商业船为 137dB re.1μPa）。结果提供了有关航行船闸环境声音景观的信息，为未来研究评估人为声音对水生生物的影响提供了基本信息。19 号船闸也被确定为潜在的声学威慑部署地点，以防止入侵鱼类的移动。本研究的结果可以帮助确定发出声音所需的声级或频率威慑，以避免在船舶通过时产生的那些声音。
