Seabed Recovers Quickly After Submarine Cable Removal, Study Finds

Seabed Recovers Quickly After Submarine Cable Removal

A new scientific study has found that the environmental disturbance caused by removing old submarine internet cables is fairly short-lived, with the seabed showing significant recovery within months. This research provides important data for the expanding subsea cable network, vital for global communications, and will directly inform future telecommunications infrastructure projects and marine policy. The findings offer a clearer picture for environmental management as the industry plans for the decommissioning of ageing systems.

The study specifically examined the physical impact on the seafloor following a standard cable removal operation. With thousands of kilometres of subsea cables forming the backbone of the internet — and approaching the end of their operational lifetime — understanding the consequences of their removal is critical for sustainable industry growth.

Analysing the Immediate Impact

The research involved monitoring a site after a decommissioned submarine cable was retrieved from the seabed. The removal process, which involves specialised vessels pulling the cable up from the ocean floor, inevitably disturbs the marine environment. The study focused on measuring the direct physical footprint left by the operation.

Scientists tracked changes to the trench created by the cable’s path, sediment displacement, and initial effects on the local seabed habitat. The data confirmed an immediate and noticeable alteration to the seafloor, consistent with the expected effects of such industrial activity.

Establishing a Speedy Natural Recovery

The core finding of the investigation was the rapid pace at which natural processes began to repair the disturbance. Observations showed that ocean currents started redistributing sediments back into the excavated trench within a very short timeframe.

Most of the visible physical scarring was remediated by natural forces within a year. The study notes that the speed of recovery is influenced by local conditions, including the strength of bottom currents and the type of sediment. Dynamic, sandy environments demonstrated a faster return to their pre-disturbance state compared to more static, muddy areas.

Implications for Global Infrastructure Planning

These findings come as the subsea cable industry faces a wave of necessary upgrades. A significant portion of the world’s existing cable infrastructure, laid decades ago, will soon require replacement, making decommissioning a routine process.

The research provides tangible evidence for telecom companies and environmental regulators. Understanding that the direct seabed impact, while initially significant, is temporary helps in planning projects with greater environmental awareness. It also assists in assessing the full lifecycle impact of cables and comparing the ecological effects of different end-of-life strategies.

Balancing Development with Ocean Stewardship

While the study highlights a resilient seabed, experts emphasise that decommissioning is only one phase of impact. A comprehensive environmental assessment must consider the entire cable lifecycle — careful route planning to avoid sensitive ecosystems, the installation process, long-term presence, and final removal.

This scientific insight supports the development of more precise guidelines and regulations. By quantifying recovery times, it enables better prediction of environmental impacts and promotes informed decision-making. The goal is to balance the undeniable need for reliable global digital connectivity with the ongoing responsibility to protect and preserve marine environments for the future.

The study concludes that with careful management and planning informed by this type of data, the essential work of maintaining and expanding undersea communications infrastructure can be carried out with a minimised and temporary environmental footprint.