Imagine you want to build a marine fish farm off the coast of your country, and you need to decide where to place it. What is the first step to choosing the ideal location, one where your fish will thrive without harming the surrounding ecosystem and its biodiversity, and without coming into conflict with other resource users?

One way to do so is through spatial planning, a tool that decision-makers use to locate coastal and offshore aquaculture facilities based on sustainability criteria.

According to the new FAO Guidelines for Sustainable Aquaculture (GSA), spatial planning must "reconcile economic, social, and environmental objectives" while benefiting the national economy and society at large.

Step one is to conduct studies of proposed aquaculture zones – including their biodiversity, climate, water depth and quality, and socio-economic contexts - as well as stakeholder surveys and environmental impact assessments.

Spatial planning for food, but also conservation and restoration

When done in an inclusive and participatory way, spatial planning can be a vehicle to forge consensus and collaboration around food production, conservation and development goals.

"It's about choosing what kind of aquaculture we want," says FAO Fishery Officer Amber Himes-Cornell. "Do we want it to prioritize food production, improvements to biodiversity, ecosystem restoration or some combination of all the above?"

For example, seaweed and shellfish cultivation have multiple benefits: they create habitats for aquatic species, improve water quality, absorb carbon, and result in food and cosmetic and pharmaceutical ingredients for people.

"Through spatial planning, decision-makers can choose the best location for a seaweed or shellfish farm that has, for example, lots of nutrient runoff from land-based agriculture," says Himes-Cornell. "The seaweed will grow by absorbing nutrients from the agricultural runoff, while the bivalves will feed on phytoplankton that thrive on these nutrients. This process helps clean the water in the area while keeping both safe for us to eat."

Strategic location choices for aquaculture farms can boost both food production and environmental conservation, helping to ensure that economic, social, and environmental goals are met.

Spatial planning for environmentally friendly offshore cage culture

Marine cage culture of finfish such as salmon has drawn criticism because the fish must be fed. Any excess feed and waste from the fish can drift down to the seabed, where it will rot, giving rise to a layer of anaerobic bacteria that kills off the biodiversity living in the vicinity. This is where spatial planning can play a key role in risk prevention, according to FAO Aquaculture Officer Alessandro Lovatelli.

"The water should be the right temperature and salinity for the farmed fish to thrive, but it should also have enough movement that their feces as well as any uneaten feed will get spread over a wide area instead of dropping to the seabed and accumulating under the cage," Lovatelli explains.

"As well, cages should be sited where the water is deep enough to guarantee a certain space between the bottom of the cages and the seabed," he notes, adding that fish farmers hate to waste aquafeed because it is expensive, and it is their biggest operational cost.

"Any farmer will tell you that losing feed is losing money," Lovatelli says. "This is why the industry has come up with innovative technologies such as cameras and remote sensing to monitor how much the fish eat, so that the farmers will know how much to feed them and when to stop feeding."

"Farmers have a strong incentive to minimize waste and safeguard the environment — both to avoid losing money on aquafeed and to maintain a healthy culture environment essential for their fish," Lovatelli concludes.

About the Guidelines for Sustainable Aquaculture

The GSA are the first global, voluntary normative document focusing entirely on aquaculture. They are an integral part of the FAO Blue Transformation Roadmap 2022-2030 and were recognized as priorities by the G20 and G7 agriculture ministers in their declarations in 2024.

The FAO GSA aim to create a more sustainable and resilient aquaculture sector, highlighted as key priorities by global leaders in recent G20 and G7 discussions.

Related links

Pêches et aquaculture de la FAO