High-Resolution Digital Twins for Marine Protected Areas

BENTHIC BIODIVERSITY, DETAILED OFFSHORE SITE SURVEY, INFRASTRUCTURE INSPECTION, SECURITY

Digital baseline of Monaco’s ecological restoration site and underwater heritage

Across 2.5 hectares, a centimetre-scale record makes it possible to measure infrastructure, track ecological change and revisit the same seabed over time.

At the foot of the Oceanographic Museum of Monaco, Cosma carried out a large-scale underwater survey to establish the digital baseline of the Toulonnais ecological restoration project. Covering more than 2.5 hectares, the survey combined high-resolution photogrammetry, autonomous underwater vehicles and artificial intelligence to document benthic habitats, underwater infrastructures and cultural heritage before the implementation of future restoration measures.

Centimetre-scale digital twin of a submarine pipeline and surrounding seabed in Monaco. — High-resolution photogrammetry generated a continuous centimetre-scale digital twin of the submarine pipeline, providing a complete georeferenced representation of its trajectory and surrounding seabed for inspection and long-term monitoring.

High-resolution photogrammetry generated a continuous centimetre-scale digital twin of the submarine pipeline, providing a complete georeferenced representation of its trajectory and surrounding seabed for inspection and long-term monitoring.

The project forms part of Monaco’s long-term ecological restoration strategy, which aims to restore coastal ecosystems while enhancing underwater heritage, scientific research and public awareness. The study area extends from the Port of Fontvieille to depths of approximately 55 metres and includes a wide diversity of habitats and underwater structures, including the Toulonnais shipwreck, rocky reefs, artificial habitats and submarine pipelines.

The digital twin documents the entire underwater infrastructure network, including pipelines, supports and protective structures, enabling accurate mapping, asset inventory and condition assessment over large areas.

The high-resolution survey also documented marine litter and abandoned artificial objects scattered across the seabed. Their precise geolocation and detailed visual characterisation can support future removal operations by identifying objects that can be safely removed, while taking into account their potential colonisation by marine organisms and interactions with surrounding habitats.

Cosma deployed lightweight autonomous underwater vehicles equipped with high-resolution optical sensors to acquire continuous georeferenced imagery across the entire site. The collected imagery was processed into centimetre-scale orthomosaics, 2D and 3D digital twins, georeferenced ground-truth imagery and an interactive web platform providing direct access to every observation collected during the survey. Artificial intelligence was used to automatically detect artificial underwater features, including pipelines and other seabed infrastructures.

Protective underwater mattress documented before significant biological colonisation.

Before-and-after imagery shows the colonisation of protective mattresses by invasive species. High-resolution, georeferenced data provide a repeatable baseline to monitor the same structures over time and detect both structural and environmental changes.

By combining autonomous robotics, photogrammetry and AI-assisted interpretation, the project provides environmental managers with a repeatable digital reference that can be revisited throughout the lifetime of the restoration programme.

Cosma’s web platform combines the centimetre-scale digital twin with every georeferenced ground-truth image, allowing users to inspect the pipeline, validate observations and seamlessly navigate between the map and the original imagery.

*Close-up imagery provides detailed visual inspection of pipeline supports, joints and engineering components, documenting their condition while preserving complete visual traceability.*

Marine litter and abandoned objects identified and precisely georeferenced across the survey area, providing actionable data to plan targeted removal operations while considering surrounding benthic habitats.

*Comparison of the 2025 and 2026 surveys enables changes to be detected and precisely documented over time, supporting long-term structural and environmental monitoring.*

Location Le Toulonnais.
Client Gouvernement Princier Monaco.
Objective Inspection of seabed pipelines and macro-waste detection and positioning.
Environment Rehabilitation around a wreck for recreational activities.
Highlight Time-lapse monitoring of susbea infrastructures for automated integrity checks.