For the first time, the “footprints” of human architecture in the ocean have been quantified.

According tomedia New Atlas, humans have indeed left their mark on Earth in a relatively short period of time because of the long history of changing the environment through man-made structures. Australian scientists have turned their attention to what this timeless development means for the world’s marine environment, calculating for the first time in history the extent of the building’s footprint on the oceans.

The study, conducted at the University of Sydney in Australia and the Sydney Institute of Marine Science, collated data on various types of marine construction. The data, which include oil rigs, wind farms, the length of telecommunications cables, commercial ports, bridges and tunnels, artificial reefs and aquaculture farms, are collected from various sectors of these different industries.

The result is what scientists call the world’s first map of the oceans, revealing how much the marine environment has been altered by human activity. According to the team, about 30,000 square kilometers of ocean have been altered by human construction, equivalent to 0.008 percent of the entire ocean. But as lead author Dr Ana Bugnot explains, the implications are far more profound.

“The impact of the structure goes beyond its immediate physical footprint,” she says. “Marine buildings can change their surroundings by changing ecological and sedimentary characteristics, water quality and hydrodynamics, as well as noise and electromagnetic fields.”

Dr Bugnot and her team used existing data and research to quantify the effects of these types of follow-up effects and found that the footprints of these structures were actually 2 million square kilometres, more than 0.5 per cent of the entire ocean. The more surprising finding in the analysis is that 40 per cent of the physical footprint of all structures can be attributed to China’s aquaculture farms, and noise pollution can be carried up to 20 kilometres from commercial ports.

Although evidence of man-made ocean changes dates back thousands of years to the early construction of ports and breakwaters to protect low-lying coasts, according to the team, the phenomenon began to accelerate around the mid-20th century. Most of this construction takes place in coastal areas, and to better understand the trend, the team looks to the future, evaluates project data in the plan, and assumes a business-as-usual approach.

“The numbers are amazing,” Dr. Bugnot said. “For example, electricity and aquaculture infrastructure, including cables and tunnels, is expected to increase by 50 to 70 per cent by 2028. Yet this is an understated figure: information on marine development is scarce because of poor regulation in many parts of the world. “

The team hopes the study will draw attention to the importance of protecting the marine environment and provide a starting point for further investigations and tools to continuously track these types of marine construction projects.

“The estimates obtained for marine construction are considerable and help to highlight the urgent concerns and needs for marine environmental management,” Dr. Bugnot said. “We hope that these estimates will lead to national and international initiatives and promote efforts for integrated global marine space planning. In order to achieve this goal, more detailed mapping of historical and existing marine habitats and marine construction is necessary. “

The study was published in the journal Nature-Sustainability.