Our directory of things of interest

University Directory

Aquaculture: farming the sea

Undersea nets used in offshore fish farming Undersea nets used in offshore fish farming Adnan Buyuk
07 Apr
2018
Increasing interest in offshore aquaculture is dividing environmentalists

What is offshore aquaculture? Aquaculture involves raising fish or shellfish in floating pens in bodies of water: farming fish as opposed to catching them in the wild. It accounts for just over half of the world’s seafood and is the fastest growing sector of food production. The ‘offshore’ part is a little trickier to define.

‘There is no global consensus about what “offshore” means exactly,’ says Halley Froehlich, a postdoctoral researcher of sustainable aquaculture. ‘In America it means operations located between three and 200 miles away from the coast, however, worldwide it means fish farms that are generally deeper and further at sea, crucially in places with a faster current.’

According to Froehlich’s research with the University of California, Santa Barbara, interest and investment in offshore aquaculture is increasing ‘at a rapid rate’. The main hope is to reduce the environmental issues of coastal aquaculture, such as introduction of diseases, pollution and pests (sea-lice, for example), by moving them further away from sensitive shorelines. Further at sea, and at deeper depths, the water movement is often faster, movement that supporters say will flush out waste and minimise pollution. ‘Carried out in a sustainable way, alongside scientific research, offshore aquaculture could mitigate some of the environmental issues of near-shore farms, at a higher rate of production,’ says Froehlich. ‘Done effectively, a small area of the world’s oceans could provide essential sources of protein for a growing population.’

Critics of offshore farming claim that moving further into the ocean would simply transport the same issues to areas where they could be harder to monitor and regulate. ‘Out of sight, out of mind,’ says Hallie Templeton, Senior Oceans Campaigner at Friends of the Earth, which has a strict position on industrial ocean fish farming. ‘Pollution, disease and pests would still be spread into the surrounding waters, whatever the depth,’ she says. ‘That is the nature of a free exchange between water and the pens.’

Others also point to the greater exposure of offshore pods to more powerful weather and water speeds, increasing the risk of all the fish escaping – known as ‘spills’. In fact, the US state of Washington is in the process of phasing out its non-native fish farms after a high-profile spill released more than 260,000 Atlantic salmon into its Pacific waters. Templeton suggests other alternatives, such as recirculating farms, which raise fish in tanks onshore and use their waste to fertilise plants, keeping the waste away from the wild ecosystems.

So far, most offshore farms are experimental projects in countries with an established aquaculture industry, such as Norway and the US. However, for the past two years, the US’ National Oceanic and Atmospheric Administration has been authorising offshore permits for the Gulf of Mexico in the hope of encouraging commercial operations. Froehlich believes this is part of an inevitable move offshore: ‘It will not be a panacea to all the problems of onshore. However, this makes it all the more crucial for scientists and conservationists to be involved in working out what is sustainable aquaculture practice.’

This was published in the April 2018 edition of Geographical magazine.

red line

NEVER MISS A STORY

Geographical Week

Get the best of Geographical delivered straight to your inbox by signing up to our free weekly newsletter!

red line

Related items

Geographical Week

Get the best of Geographical delivered straight to your inbox every Friday.

LATEST HEADLINES

Subscribe to Geographical!

University of Winchester

EDUCATION PARTNERS

Aberystwyth University University of Greenwich The University of Winchester

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • The Human Game – Tackling football’s ‘slave trade’
    Few would argue with football’s position as the world’s number one sport. But as Mark Rowe discovers, this global popularity is masking a sinister...
    Essential oil?
    Palm oil is omnipresent in global consumption. But in many circles it is considered the scourge of the natural world, for the deforestation and habita...
    Hung out to dry
    Wetlands are vital storehouses of biodiversity and important bulwarks against the effects of climate change, while also providing livelihoods for mill...
    The true cost of meat
    As one of the world’s biggest methane emitters, the meat industry has a lot more to concern itself with than merely dietary issues ...
    The Air That We Breathe
    Cities the world over are struggling to improve air quality as scandals surrounding diesel car emissions come to light and the huge health costs of po...

MORE DOSSIERS

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Wildlife

The demand for horseshoe crab blood – vital for testing…

Climate

One of the problems in getting accurate climate science out…

Wildlife

Italy is divided over the future of its wolves and…

Energy

A Scottish tidal power project in the Pentland Firth has…

Oceans

The world’s first full global analysis of beaches reveals the…

Geophoto

With the recent Saddleworth Moor fire, it can be easy…

Wildlife

Whale sharks have been found to not travel far from…

Wildlife

The Lone Star tick is spreading across North America, carrying…

Tectonics

Earlier this week, Indonesia was struck by a series of…

Energy

Efforts to reduce the energy drain of the internet are…

Energy

Coal’s rising popularity among climate-apathetic leaders is a worrying trend,…

Climate

Sharing the ideas of climate justice with a little humour…

Polar

Rising bedrock under the West Antarctic Ice Sheet could prevent…

Oceans

Officially declared the world’s ‘most overfished sea’, the Mediterranean is…

Wildlife

An interview with biologist Chris D Thomas, author of ‘Inheritors…

Geophoto

Some may see using the 50mm lens as a regressive…

Oceans

With the war against plastic gaining publicity and popularity, one…

Wildlife

India’s booming domestic dog population is attacking some of the…

Energy

Soaring sales of air conditioning units over the next thirty…

Climate

Well-meaning promises and actions don't always have the best outcomes.…