Pan Ocean Aquaculture's giant cage will be moored in the Taiwan Strait for farming a popular Asian species. Photo: Pan Ocean Aquaculture

A new mega-cage sets off for the sea

It’s round, yellow and huge and it’s built for offshore use – but the latest mega-cage to leave a Chinese construction yard isn’t a carbon copy of SalMar’s Ocean Farm 1 and it’s not going to hold salmon, although it is suitable for them.

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The cage – called the Semisubmersible Spar Fish Farm (SSFF) – will be operated in the Taiwan Strait, which separates Taiwan from mainland China, and will hold up to 3,000 tonnes of yellow croaker, also known as corvina, a fish mainly eaten in Asia.

It will be sunk to around 10 metres below the surface during storms.

Mark Van Leeuwen: Cage cost arounf £13.7m.

Marine engineers

The company behind the cage is Pan Ocean Aquaculture, which comprises four men from the Netherlands with marine engineering backgrounds.

General manager Mark Van Leeuwen told Fish Farming Expert’s Norwegian sister site,, that the total cost of building the cage was around 120 million Chinese yuan (£13.7m). One of the investors is the government of the south-eastern province of Fujian, which has a coastline on the Taiwan Strait.

The cage was designed by De Maas SMC, which provides technical services required for design, construction and completion of tailor-made vessels and platforms for oil and gas, offshore renewables and offshore farming. De Maas also oversaw construction in China.

Yellow corvina (Larimichthys polyactis) will be farmed in the SSFF.

Shark-proof netting

The SSFF uses 4mm copper net. “A shark would not get through this and copper has many advantages such as anti-biofouling,” Van Leeuwen told, who added that the cage was suitable for salmon.

“By submerging you will have fewer problems with sea lice,” he explained.

Although the cage is big by aquaculture standards, its size is not what excites Pan Ocean Aquaculture.

“It’s all a matter of perspective,” the company said in a recent post on LinkedIn. “To the aquaculture industry, our SSFF is the largest diameter pen the world has ever seen, while for those with an offshore engineering background it is an innovative, exciting and fascinating but not particularly large offshore engineering project.”