The primary purpose of this report is to use a literature review to determine the potential global pressures and impacts that submarine cables have on marine biodiversity and to identify potential opportunities for any negative impacts to be mitigated. To achieve these aims, this report:

1. provides a review of the environmental pressures associated with submarine cables
2. appraises the potential impacts of submarine cables using an established framework
3. lists ways to minimize potential negative impacts
4. identifies opportunities to enhance biodiversity knowledge and understand the ocean environment using cable systems, while ensuring that the digital infrastructure remain resilient
5. determines key recommendations for a variety of stakeholder groups to consider

The scope of this report is global. It spans diverse settings from the deep ocean (defined in this report as >1,500 m) where cables are laid on the seafloor, to shallower seas (defined in this report as 0-1,500 m) where cables are typically buried for their own protection (damage to cable is often caused by accidental interactions with bottom-contact fishing and anchoring). Because the findings are a synthesis of a large body of evidence, specific situations might differ from the report’s overall conclusions.

Overall, the analysis found that submarine cables have a relatively small footprint in the marine environment. Globally less than 0.01% of the seafloor is within 10 meters (m) of submarine cables, indicating that the global spatial footprint of submarine cables is currently minimal.