Paired comparisons with quiet surface drones show evidence of fish behavioral response to motorized vessels during acoustic surveys in Lake Superior
Acoustic surveys are important for fish stock assessments, but fish responses to survey vessels can bias acoustic estimates. We leveraged quiet uncrewed surface vessels (USVs) to characterize potential bias in acoustic surveys. Five conventional motorized ships overtook USVs from astern over 2 km transects at night in Lake Superior in 2022. We examined the difference in acoustic backscatter, average target depth, and average target strength (TS) between USV and motorized vessels. Although sound level measurements from the motorized vessels sometimes exceeded recommendations for scientific vessels, we did not detect differences in acoustic measures among survey vessels. However, the USVs recorded 2 dB higher acoustic backscatter and TS than motorized vessels, leading to ∼15% higher fish densities with drones when using in situ TS and echo integration. Differences in fish density would increase to 30%–60% if a standard TS value was applied. Target depth did not differ between USVs and motorized ships. These results are consistent with a change in orientation but not depth of insonified fish and limited horizontal avoidance of motorized survey vessels.
Authors
- Hannah Blair (ORCID: https://orcid.org/0000-0003-2895-1951)
- David M. Warner (ORCID: https://orcid.org/0000-0003-4939-5368)
- James M. Watkins (ORCID: https://orcid.org/0000-0002-8053-1850)
- Steven A. Farha (ORCID: https://orcid.org/0000-0001-9953-6996)
- Lars G. Rudstam (ORCID: https://orcid.org/0000-0002-3732-6368)
- Peter C. Esselman (ORCID: https://orcid.org/0000-0002-0085-903X)
- Thomas M. Evans (ORCID: https://orcid.org/0000-0001-6717-4521)
- Suresh A. Sethi (ORCID: https://orcid.org/0000-0002-0053-1827)
- Steven Senczyszyn (ORCID: https://orcid.org/0000-0003-4604-6525)
- Kayden C. Nasworthy (ORCID: https://orcid.org/0000-0002-6574-9915)
- Ian C. Harding (ORCID: https://orcid.org/0000-0003-4281-0581)
- James J. Roberts (ORCID: https://orcid.org/0000-0002-4193-610X)
- Bradley A. Ray
- Edmund J. Isaac (ORCID: https://orcid.org/0000-0002-3712-503X)
- Daniel L. Yule (ORCID: https://orcid.org/0000-0002-0117-5115)
- Mark R. DuFour (ORCID: https://orcid.org/0000-0001-6930-7666)
- Joshua E. Blankenheim
- Timothy P. O’Brien (ORCID: https://orcid.org/0000-0003-4502-5204)
- Andrew Barnard (ORCID: https://orcid.org/0000-0003-3276-8113)
Institutions
- Michigan Technological University (US)
- United States Geological Survey (US)
- Pennsylvania State University (US)
- Minnesota Department of Natural Resources (US)
- Cornell University (US)
- Wisconsin Department of Natural Resources (US)
- Fond du Lac Reservation (US)
- Great Lakes Science Center (US)
- Red Cliff Band of Lake Superior Chippewa (US)
- Michigan United (US)
- University of Minnesota, Duluth (US)
- Aquatic Systems (United States) (US)
- Louisiana Department of Natural Resources (US)
- University of California Division of Agriculture and Natural Resources (US)
- Brooklyn College (US)
- Ashland (United States) (US)
Publication Details
- Journal
- Canadian Journal of Fisheries and Aquatic Sciences
- Published
- 2024-08-15
- DOI
- https://doi.org/10.1139/cjfas-2024-0087
- Citations
- 2
- Primary Topic
- Fish Ecology and Management Studies
- Type
- article
- Field-Weighted Citation Impact
- 1.38
Funders
- U.S. Geological Survey