Large scale application of stereo baited remote underwater video systems to support monitoring of temperate marine ecosystem in the Northeast Atlantic.Science to Policy

Owen Exeter¹

¹University of Exeter, UK

Marine ecosystems and protected areas (MPAs) often lack adequate data on the status of marine assemblages to support evidence-based management. Stereo baited remote underwater video systems (BRUVS) offer a powerful, low-cost tool for collecting ecosystem-wide ecological data, yet they remain underutilised in the North East Atlantic, especially as a low impact, fisheries independent method.

This study presents the findings of a survey comprising 280 stereo-BRUVS deployments, designed to support holistic marine monitoring for the Isles of Scilly archipelago; a regionally important biodiversity hotspot. Given the archipelago’s unique biogeography, clean waters and isolation, local marine ecosystems are perceived as being in a relatively pristine condition. This survey therefore represents an opportunity to generate modern benchmarks of what healthy temperate reef ecosystems could look like, relative to the highly degraded wider Northeast Atlantic.

Focusing on reef-associated marine assemblages, results establish a contemporary benchmark of species richness, abundance, and biomass, and establish the key environmental drivers and areas of elevated biodiversity; notably remote circalittoral reef systems. Multivariate analyses also delineate ecologically distinct management zones and their corresponding indicator species, laying the groundwork for a long-term monitoring strategy in the region.

This study highlights the effectiveness of stereo BRUVS as a flexible and cost-efficient tool for sampling in European temperate waters. To our knowledge, this represents one of the largest and most spatially comprehensive stereo BRUV survey conducted in the Northeast Atlantic. Survey results have significant implications for local management, highlighting the ecological importance of isolated, topographically complex reef sites, notably for conservation concern but commercially targeted species including spiny lobsters (P. Elephas) and benthic sharks (i.e. S. Stellaris).