PORTSMOUTH, United Kingdom--(BUSINESS WIRE)--The global network of subsea telecommunications cables carries more than 99% of digital data traffic worldwide. In shallow waters, these cables are buried beneath the seafloor to protect them from the harmful impacts of fishing and ship anchors. While the act of cable burial can disturb the seafloor, scientific studies have shown the impacts to ocean life to be short-lived. However, to date no study has assessed whether cable burial may also disturb important stocks of organic carbon stored in seafloor sediments. Unknown to most, seafloor sediments store significant quantities of organic carbon, playing a critical role in regulating global climate.
A new peer-reviewed study published in Nature Communications provides the first global assessment of this disturbance. The study found that cable burial may have disturbed a total of 3-11 million tons of seafloor carbon over several decades. While this sounds like a large number, the study places the estimated disturbed volume of carbon in a wider context. Lead author of the study, Dr Michael Clare of the UK’s National Oceanography Centre (and ICPC Marine Environmental Adviser) commented, ‘Many natural events such as underwater landslides, earthquakes and storms disturb similar or even larger volumes of carbon in an individual event. Indeed, the total volume of disturbed carbon by cable burial over multiple decades is in orders of magnitude less than that disturbed by bottom fishing in a single year.’
As undersea cables are buried to protect them from the impacts of fishing in shallow waters, the study goes on to suggest that if fishing activities were restricted around cable routes, this could reduce the need for burial. In turn this could limit seabed disturbance, ensuring carbon stocks remain locked up. The study also suggests that there is a need to quantify the carbon disturbed by other offshore industries. ICPC Chair Graham Evans added that ‘It is important to understand how to minimise impacts on the marine environment, whilst also ensuring cables remain resilient. There is true value in independent peer-reviewed research and findings.’
As this is the first study of its kind, it is not yet known precisely how much carbon is lost as a result of cable burial. ‘The most commonly used tools to bury cables, such as ploughs, may simply result in rapid re-burial of carbon with little loss, many areas of seafloor contain relatively unreactive carbon that will not be affected, and our study also finds that most cable routes have avoided important hotspots that are richer in organic carbon,’ said Dr Clare, continuing ‘Future field and laboratory studies will help to close out the uncertainties on precisely how much carbon is remineralised as CO2.’
This research was undertaken by a team of independent researchers from the UK (National Oceanography Centre, Leeds University) and Austria (ETH Zürich) and was supported by the Natural Environment Research Council (‘Climate Linked Atlantic Sector Science’) and the International Cable Protection Committee to better understand the effects of human activities in the ocean.
The study ‘Assessing the impact of the global subsea telecommunications network on sedimentary organic carbon stocks’ is published in Nature Communications and can be accessed here.
About the ICPC. The ICPC is the world’s premier submarine cable protection organisation. It was formed in 1958 to promote the protection of submarine cables against human-made and natural hazards. It provides a forum for the exchange of technical, legal, and environmental information about submarine cables and engages with stakeholders and governments globally to promote submarine cable protection. The ICPC has over 200 Members from 69 nations, including cable operators, owners, manufacturers, industry service providers, as well as governments. For further information about the ICPC, see www.iscpc.org and www.linkedin.com/company/icpc-ltd/.
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