This week a 1200m undersea fibre-optic cable linking Finland and Germany was severed. The two countries said in a joint statement that they were investigating the incident, which “immediately raises suspicions of intentional damage”. Europe’s security is threatened by Russia’s war against Ukraine. The joint statement described the incident as “hybrid warfare by malicious actors” and noted that safeguarding “our shared critical infrastructure is vital to our security and the resilience of our societies”. 

Last week an Irish patrol vessel escorted a Russian oceanographic research vessel, widely regarded as a spy ship, from the vicinity of sensitive cables in the Irish Sea after it was observed loitering and operating drones in the area.

In March we had the Rubymar incident. The bulk carrier was damaged by missiles from Houthi forces in the Red Sea and subsequently abandoned. While drifting, it cut three subsea data cables connecting Europe and Asia. Salvage companies couldn’t intervene as they feared coming under attack.

Up to 99 per cent of transregional digital data today is transported by the global subsea data cable system. This system is the backbone of the internet and digital communications. But the network is vulnerable and open to failure and direct attack. Island states are especially at risk as a single failure can have dramatic consequences and even lead to the shutdown of the economy, as we’ve seen by several cable failures connecting Tonga.

Australia has yet to adequately grapple with the unique challenges that critical seabed infrastructure protection poses to our national security. Significant sums are invested into submarine networks that connect Australia. Of the $29.14bn invested in new submarine cable networks between 2014 and last year, $3.62bn was spent in Australia – 12 per cent of the global total. Of the $16.1bn set to be spent on under-construction and high-credibility proposed submarine cable projects, about $1.72bn will be spent on Australian cables – 10 per cent of the global total. 

A key element of submarine cable networks is the landing stations. They mediate data between submarine cables and terrestrial networks or data centres. Our main landing stations are in Sydney and Perth. But in the future, there’ll be more diversification of our international landing points. Last year, the Darwin-Jakarta-Singapore cable was completed, resulting in the first international submarine cable connection into Darwin.

While submarine data cables are the most important seabed links between Australia and the world, the sea and the seabed will house a growing number and variety of green energy generation facilities. Offshore renewable energy farms will appear on our coasts with new seabed infrastructure. Offshore solar farms and wave energy connectors will introduce more critical seabed infrastructure. Seabed electricity cables will grow in prominence in Australia. Whether we go down the path of Denmark – which has plans for “energy islands” to be built up to 100km into the North Sea to provide for the substations, a harbour and service facilities – remains to be seen. 

There’s a range of threats and risks to offshore wind farm systems, whether it be the wind turbines, their land-based substations or undersea connecting cables. There’s the potential for a collision between a ship and a wind turbine or substation at sea. Damage to undersea power cables could be caused from ship anchors or fishing practices such as bottom trawling. There’s potential for theft and vandalism, especially copper theft. There’s the potential for cyber attacks that target a wind farm network. 

A terrorist attack on offshore wind farm infrastructure shouldn’t be discounted. Given the growing importance of underwater electricity grids and offshore wind farms for our longer-term energy security, this infrastructure will be a plausible target in any conflict.

Australia has established an Indo-Pacific Cable Connectivity and Resilience Centre to provide technical assistance and commission research to improve the management of submarine cable networks across the region. We’re countering the growing proliferation of submarine cable networks owned by Chinese firms by investing in new cable projects across the Pacific. Australia owns a substantial share of the communications cable that connects Sydney with Port Moresby and Honiara. We’re in partnership with the US and Japan to fund the East Micronesia cable, which will connect the Federated States of Micronesia, Tarawa in Kiribati and Nauru to an existing cable system.

But little has been done to address possible damage caused by hostile nations or proxies. Our civil maritime security strategy issued two years ago was silent on protecting critical seabed infrastructure. This year’s Australian National Defence Strategy didn’t mention seabed infrastructure and communication cables. 

Last year our Defence Department announced the purchase of the 107m-long Norwegian-flagged MV Normand Jarl. It has been renamed the Australian Defence Vessel Guidance. Defence noted that the vessel would support “undersea surveillance systems trials, including the ability to deploy undersea crewed and uncrewed vehicles, and robotic and autonomous systems”. The vessel’s exact role hasn’t been disclosed.

There’s some promise that AUKUS could have a useful role in seabed protection. There is the AUKUS Undersea Robotics Autonomous Systems project. But there’s no information to link this project to civilian critical seabed infrastructure protection. In November last year Britain, the US and Australia jointly conducted an exercise off our east coast that tested autonomous undersea warfare capabilities. Our new ADV Guidance participated in the exercise. 

Seabed infrastructure protection needs to be better integrated into our defence and maritime security strategies. When a potentially hostile seabed incident occurs, as well as swiftly repairing the damaged infrastructure, urgent investigations must ensue to identify the culprit. 

But these tasks are often complicated by the remoteness of the incident location, coordination with private industry, by the depth of the break, by jurisdictional issues and by prevailing geopolitical tensions. In a crisis, access to highly specialised cable-repair ships would be challenging.

Incident response could be facilitated by a new co-ordination body within our navy or the Department of Home Affairs. We need to acquire capabilities to monitor and protect critical seabed infrastructure. We don’t yet know if the new ADV Guidance will play such a role.

Google, Amazon and Microsoft increasingly are investing in submarine cable projects.

Indeed, most of the critical seabed infrastructure is owned, operated and repaired by the private sector. Coordination between navy, government and industry stakeholders is critical. We need to better protect seabed infrastructure by including such assets in our critical infrastructure protection policies. These aim at co-ordinating risks assessments and security responses across various industry sectors. But underwater fibre-optic cables, electricity cables and wind farms have hardly featured in these policies. 

The seabed is a new challenge for all nations. Uses of the seabed have multiplied, with a growing density of infrastructure.

We should be alert to opportunities for ocean diplomacy concerning critical seabed infrastructure protection, even if that infrastructure is mostly invisible to the public and policymakers.

Anthony Bergin is a senior fellow at Strategic Analysis Australia. Samuel Bashfield is a research fellow at the Australia India Institute.  This article first appeared in the Weekend Australian.