<scp>The Underwater Vision Profiler 6: an imaging sensor of particle size spectra and plankton, for autonomous and cabled platforms</scp>

TLDR

Autonomous and cabled platforms enable 4‑D monitoring of the water column, yet few commercially available sensors can track large particulate matter (100–2000 µm) and plankton, which are key to the biological carbon pump and trophic transfer. This study introduces the Underwater Vision Profiler 6 (UVP6), a compact, low‑power, camera‑based particle counter designed for deployment on autonomous and cabled platforms. The UVP6 employs a camera‑and‑lighting system with adjustable settings, performs real‑time particle and plankton detection, applies quality control, analyzes recordings, and streams data directly to users. UVP6 delivers data quality comparable to larger ship‑borne UVPs, has been integrated into BGC‑Argo floats, gliders, and moorings, and its deployment results demonstrate its utility for addressing longstanding marine science questions and opening new research avenues.

Abstract

Autonomous and cabled platforms are revolutionizing our understanding of ocean systems by providing 4D monitoring of the water column, thus going beyond the reach of ship-based surveys and increasing the depth of remotely sensed observations. However, very few commercially available sensors for such platforms are capable of monitoring large particulate matter (100-2000 μm) and plankton despite their important roles in the biological carbon pump and as trophic links from phytoplankton to fish. Here, we provide details of a new, commercially available scientific camera-based particle counter, specifically designed to be deployed on autonomous and cabled platforms: the Underwater Vision Profiler 6 (UVP6). Indeed, the UVP6 camera-and-lighting and processing system, while small in size and requiring low power, provides data of quality comparable to that of previous much larger UVPs deployed from ships. We detail the UVP6 camera settings, its performance when acquiring data on aquatic particles and plankton, their quality control, analysis of its recordings, and streaming from in situ acquisition to users. In addition, we explain how the UVP6 has already been integrated into platforms such as BGC-Argo floats, gliders and long-term mooring systems (autonomous platforms). Finally, we use results from actual deployments to illustrate how UVP6 data can contribute to addressing longstanding questions in marine science, and also suggest new avenues that can be explored using UVP6-equipped autonomous platforms.