THE DEVELOPMENT AND APPLICATION OF BRUVS-LITE: A STEREO-BRUV SYSTEM WITH INTEGRATED LIGHTING FOR SEASCAPE ECOLOGY
Date
2025-04-09
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Abstract
Baited Remote Underwater Video Systems (BRUVS) are widely used in marine ecology but remain understudied in low-light environments and northern latitudes. Within seascape ecology, a key focus is edge habitats (ecotones), which describe zones of transition between habitats of differing structural complexity. Previous ecotone research has predominantly occurred in habitat types displaying clear boundaries (e.g., seagrasses). Knowledge gaps remain regarding environments characterized by broad-scale heterogeneity and gradual transitions. Use of BRUVS to assess ecotones is controversial, as bait may introduce sampling biases. This research presents BRUVS-Lite, an open-source, cost-effective, stereo-BRUVS with integrated lighting. Assessment of the measurement accuracy of BRUVS-Lite was conducted, focusing on the impact of routine system handling on calibration stability. BRUVS-Lite was applied for seascape ecology within the Eastern Shore Islands, Nova Scotia, to investigate ecotones between rocky reef and sand habitats, while evaluating the effectiveness of baited and un-baited deployments in detecting species-habitat relationships.
Description
Baited Remote Underwater Video Systems (BRUVS) are cost-effective and non-invasive monitoring tools used widely throughout marine ecology. Since their development, the use of BRUVS has expanded considerably. However, most BRUVS surveys have been conducted in the photic zone of the Southern Hemisphere, with limited studies exploring their effectiveness in low-light or aphotic environments. Furthermore, BRUVS in these regions typically lack integrated lighting and record continuous video over short deployment durations. Significant knowledge gaps remain regarding the use of BRUVS in northern latitudes.
Seascape ecology, a rapidly emerging field in marine research, draws from concepts established in landscape ecology to examine the influence of habitat structure on species distributions and ecological processes. A key focus within seascape ecology is edge habitats, or ecotones, which describe zones of transition between habitats of differing structural complexity. In marine ecosystems, ecotone research has typically focused on discrete habitat types displaying clear boundaries (e.g., seagrasses). Significant knowledge gaps remain in marine environments characterized by more broad-scale heterogeneity and gradual transitions. Additionally, the use of BRUVS to assess marine ecotones is controversial, as the use of bait may introduce biases that obscure natural habitat associations.
This research presents BRUVS-Lite, an open-source, cost-effective, and user-friendly stereo-BRUV system with integrated lighting, and its application for seascape ecology. This study details the design, and proof-of-concept testing of BRUVS-Lite. Additionally, an assessment of the length measurement accuracy of BRUVS-Lite was conducted, focusing on the impact of routine system handling on stereo-camera calibration stability. Finally, BRUVS-Lite was applied for seascape ecology within the Eastern Shore Islands, Nova Scotia, to investigate the marine ecotones between rocky reef and sand habitats. Both baited and un-baited deployments were conducted to evaluate the effectiveness of each methodology in detecting species-habitat relationships along ecotones. Additionally, this study aimed to provide recommendations for the optimal BRUVS-Lite deployment duration.
This study demonstrates the effectiveness of BRUVS-Lite as a monitoring tool across diverse marine environments. However, routine system handling was found to significantly impact calibration stability, emphasizing the need for system calibration before and/or after each deployment for accurate length measurements. BRUVS-Lite effectively detected ecotone effects across both baited and un-baited deployments. The use of bait was not found to obscure species-habitat relationships, however, reactions to bait were generally considered to be species-specific. The optimal BRUVS deployment duration in this region was found to be approximately 6-7 hours. By addressing knowledge gaps in both BRUVS methodology and seascape ecology, this study aims to advance our understanding of species-habitat relationships in temperate ecosystems and inform best practices for BRUV-based ecological monitoring in northern latitudes.
Keywords
Ecology, Technology, Seascape Ecology