Greenhouse gas plea to fish farms

Despite its sub-aquatic setting, the global fish-farming industry is responsible for about the same amount of greenhouse gas (GHG) emissions as the sheep industry, according to research.

In the first study of its kind, researchers including workers from Scotland’s Rural College (SRUC) and the UN’S Food and Agriculture Organisation, found that, in 2017, the aquaculture sector generated the equivalent of 263 million tonnes of carbon dioxide – nearly 0.5 per cent of those attributable to man.

The paper published by Nature.com found that, while the level of GHGS in aquaculture varied by system, the emissions from feed production generally dominated, although some systems, especially shrimps, also used a lot of energy for pumping water.

SRUC climate change researcher Dr Michael Macleod, who led the study, said aquaculture made an important contribution to food security, while acting as a driver of economic development.

He said: “But to enable sustainable expansion of aquaculture, we need to understand its contribution to global greenhouse gas emissions and how it can be mitigated.”

Dr Macleod said it was important that the industry considered ways to reduce emissions, which could also improve financial performance:

“There are lots of ways to reduce emissions, including developing genetically improved breeds suitable for lower feed conversion rates, improving health, using more precise feeding methods and improving on-farm energy efficiency,” said Dr Macleod.