on 12 Jan 2021
A first-ever survey of marine-built structures projects rapid growth
A study first published in 2020 has revealed that manmade structures now cover 32,000 square kilometres of seacapes and coastlines. That’s a size greater than the total area of Belgium. The authors of the report, a consortium of researchers from Australia, Italy and the UK, projected that the area of seascape altered by human construction would rise to 39,000 square kilometres by 2028, an increase of over 20% in just eight years.
Calculating the true extent of seascape construction was made difficult due to much of the construction being underwater. The report covered structures such as ports, oil rigs and underwater sea cables. The conclusions likely underestimated the true scale and impact of manmade structures in the ocean.
The report said that marinas were the fourth biggest manmade structure in ocean waters, after aquaculture, commercial ports and artificial reef structures. Approximately half of US coastline has been impacted by construction and development, limiting biodiversity and impacting ocean health. China and its Exclusive Economic Zone (an ocean area extending 200 nautical miles from shore) was now responsible for approximately 40% of global ocean construction.
The authors also suggested that such structures would leave shorelines more vulnerable to sea-level rise, in addition to damaging habitats.
Land reclamation is a major source of coastal disturbance. Between 1950 and 2008, China reclaimed 13,380 square kilometres of land.
Manmade islands accounted for 282 square kilometres of seascape construction area, with 479 man-made islands found by the research team. The world’s largest manmade island is 970 square kilometres in the Netherlands, and which constitutes almost the entire province in the Netherlands. The island was completed in 1968. More recent projects are located in the UAE and the Maldives, as well as new offshore airport structures.