How four big industries are driving the exploitation of our oceans

From deep-sea mines to aquaculture, bioprospecting and energy generation, humanity’s accelerating expansion into the high seas has potentially huge consequences for its health

By Graham Lawton

BLUE BUSINESS: Power and comms

The world’s first offshore wind farm opened off the coast of Lolland, Denmark, in 1991. Since then, the global installed capacity has grown to nearly 35 gigawatts – enough to power the entire UK – almost all of it in European (25 GW) and Chinese (9 GW) waters. Other sources of ocean renewable energy are also being eyed up, including waves, tides, currents, salinity gradients, thermal gradients and marine biomass. The EU has a target of installing 1 GW of these alternative sources by 2030, says Benjamin Lehner at the Dutch Marine Energy Centre in The Hague.

All these figures are a drop in the ocean compared with the world’s 1840 GW of gas-fired power capacity. Yet with wind power generation getting cheaper all the time – costs declined 70 per cent between 2012 and 2021 – rapid growth looks like a foregone conclusion. The trade association Wind Europe estimates that, by 2050, Europe will have 450 GW of offshore wind.

That brings its own challenges. It will require about 45,000 square kilometres of ocean, most of it between 11 and 22 kilometres from shore, the goldilocks zone for offshore wind. Europe has 550,000 square kilometres of this real estate in total, but more than 60 per cent is earmarked for marine protected areas, says António Sarmento at consultancy firm WavEC Offshore Renewables in Lisbon, Portugal. Building, operating and maintaining offshore wind farms can damage the seabed, while the power cables that carry electricity to shore …