Satellite mapping reveals the impact of industrial activities on waters

A study published in the scientific journal Nature this January 3 and promoted by Global Fishing Watch, a company launched by Google in partnership with Oceana and SkyTruth to monitor fishing activities by providing a global vision, has detected the impact of the activities of industrial ships and energy infrastructures in coastal waters since 2017 to 2021.The analysis was carried out through a combined use of GPS data from ships, satellite images and models deep learning, and aims to propose a broader vision of theindustrial and commercial activity in the oceans, outlining, albeit partially, a first mapping of theanthropogenic activity on the maritime environment.The reason why such a study was conducted is well explained in the very first lines of the article:“The world's population increasingly relies on the ocean for food and energy products and for trade, yet human activity in the sea it is not properly quantified”, unlike the terrestrial one.Having an initial overview of human activity on the waters is invaluable in this sense increase awareness on environmental issues and to increase our “understanding of where and how the blue economy is expanding and how it is impacting developing nations and coastal communities”.

To conduct the study, 2 petabytes (the equivalent of 2000 terabytes) of satellite images between 2017 and 2021, corresponding to over 15% of the ocean surface, in which more than 75% of industrial activity is concentrated.In order to support their own investigations, scientists have also developed three different convolutional neural networks, a particular type of artificial neuronal network inspired by the organization of the animal visual cortex;these, equipped with over 97% accuracy, have contributed to mapping and classifying human activities and the type of vessels detected (whether fishing or not), as well as categorizing the different offshore platforms into oil, wind and other.In addition to satellite images and artificial intelligence, they were collected 53 billion GPS locations of ships, provided by Automatic Identification Systems.The latter, in addition to contributing to the mapping, were combined with data provided by satellite images to determine whether the ships were publicly tracked or not.

Between 2017 and 2021, an average of around 63,300 vessels were detected sailing the sea at the same time, of which just under half (42% to 49%) related to fishing.Again with regards to fishing vessels, approximately three quarters of them on a global scale they did not appear in public monitoring systems, a ratio that drops to a quarter if you look at the ships not dedicated to fishing, and therefore those aimed at transport and industrial ones.Ship activity is distributed on a global scale over almost the entire surface analyzed, but concentrated in waters less than 200 meters deep, which constitute 7% of the ocean surface.In particular, the 67% of naval activity it was detected in Asia, followed by 12% in Europe, 7% in North America and Africa, 4% in South America and 2% in Australia.During the 2020 pandemic, fishing activity decreased by 12%, and in 2021 it did not recover to pre-pandemic levels, while the other vessels appear not to have felt the blow.

Regarding platforms, the study finds that in 2021 the number of maritime structures scattered across the oceans was 28,000.Specifically, 48% of them were made up of wind turbines located in large production areas, while 38% the oil platforms (also in vast production areas).The remaining 14% consisted of wind and oil platforms in smaller production areas, ports, bridges, transmission cables, aquaculture and other man-made structures.As for the oil platforms, most of them were located in the 13 major production areas, at the top of which we find the Gulf of Mexico;at the end of 2021, about a quarter of oil rigs were US ownership, while Saudi Arabia and Indonesia were in second and third place respectively.Wind platforms are mainly located instead in Europe (52%) and China (45%) and in the previous ten years they grew by 16% on a global scale.China led the ranking dedicated to the development of wind power platforms, so much so that between 2017 and 2021 the number of Chinese-owned structures increased increased by 900% (with an average of 950 per year), while in Europe we found Germany and the United Kingdom at the top, with an increase of 49% and 27% respectively.

The study published by Nature it is still partially partial, but it is the largest ever conducted so far and constitutes a first attempt at complete mapping of the waters.The analysis conducted by the scientists of Global Fishing Watching, in addition to providing us with invaluable information progress data of industry, commerce and production in the various countries of the world, can be of vital importance to address the problem with greater awareness climate crisis, perhaps proposing more effective agreements and interventions than those that emerged from the previous one Cop28.As the article itself suggests in the conclusions, the data that emerged can in fact "help quantify the extent of greenhouse gas emissions from ships and offshore platforms", and contribute to the development of new strategies to be carried forward following the rigidity and safety of the data.

[by Dario Lucisano]