A novel use of Stereo Baited Remote Underwater Video and Drop-Down Video for biodiversity and marine landscape mapping and prediction

PLOS ONE | https://doi.org/10.1371/journal.pone.0319355 April 3, 2025 1 / 23 OPEN ACCESS Citation: Walker-Milne N, Elliott SAM, Wright PJ, Bailey DM (2025) A novel use of Stereo Baited Remote Underwater Video and Drop-Down Video for biodiversity and marine landscape mapping and prediction. PLoS ONE 20(4): e0319355. https://doi.org/10.1371/ journal.pone.0319355 Editor: Satheesh Sathianeson, King Abdulaziz University, SAUDI ARABIA Received: March 14, 2024 Accepted: January 31, 2025 Published: April 3, 2025 Copyright: © 2025 Walker-Milne et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data availability statement: All data files are available from the Github database accessed from the following URL (https://github.com/ NWMilne/Seascape_mapping). Funding: NWM was in receipt of a PhD studentship funded by Ministry of Business, Innovation and Employment, in collaboration RESEARCH ARTICLE A novel use of Stereo Baited Remote Underwater Video and Drop-Down Video for biodiversity and marine landscape mapping and prediction Natasha L. Walker-Milne 1☯*, Sophie Elliott2☯, Peter J. Wright 3,4‡, David M. Bailey 1‡ 1 School of Biodiversity, One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom, 2 Game and Wildlife Trust, Salmon and Trout

Research Centre, Wareham, United Kingdom, 3 Marine Scotland Science, Aberdeen, United Kingdom, 4 Marine Ecology and Conservation Consultancy, Ellon, United Kingdom ☯ These authors contributed equally to this work ‡ These authors also contributed equally to this work * natasha.walker-milne@glasgow.ac.uk Abstract To make the best-informed decisions on managing marine resources whilst also restor- ing biodiversity, the creation and analysis of benthic maps is highly valuable. This study focuses on benthic mapping to study patch - and landscape - level processes affecting epifauna and demersal species using Stereo Baited Remote Underwater Video (SBRUV) and Drop-Down Video (DDV) surveys. Surveys were conducted within the South Arran Marine Protected Area between 2013–2019 and yielded 554 SBRUV data points and 333 DDV data points. These data were processed to determine proportional coverage of sub- strata and kriged to produce benthic maps. From this it was possible to estimate the patch scale of substrata to gain a more detailed understanding of the marine landscape, com- position structure, and epibenthic biodiversity. The resulting validated maps allowed the number of substrata patches and patch characteristics such as area and perimeter-to-area ratio to be calculated to support management and understanding of the value of this sea- scapes for benthic and demersal biodiversity. Our approach allowed for the identification of areas of higher biodiversity that may assist during mapping of Marine Protected Areas’

(MPA) vulnerable features. These methods should provide better information about site condition and ecosystem service provision than existing methods. Introduction Maps of seabed geology, biogenic habitats and biodiversity are essential to several areas of conservation, including the selection and monitoring of marine protected areas (MPAs), and ecosystem-based fisheries management. Changes in the extent and fragmentation of features such as seagrass or maerl beds are indicators of the success of a protected area designed to conserve these seabed types [1]. To support fisheries, we also need to know where essen- tial fish habitat is and identify measures of the value of different substrata and patch sizes.