FISH farming is just as polluting as the sheep industry, according to world's-first research from Scotland's Rural College (SRC).

SRC researchers have quantified the greenhouse gas emissions from the world's aquaculture.

They found the sector generates 263 million tonnes of carbon dioxide equivalent every year.

That puts it on par with sheep farming.

Published by Nature.com, the study was carried out to raise awareness of how and why the harmufl emissions arise in aquaculture supply chains and was completed in conjuction with the UN's Food and Agriculture Organisation and US food corporation Cargill.

Dr Michael MacLeod, who led the research, said: “Global aquaculture makes an important contribution to food security and is also a driver of economic development.

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

“While the emissions from fish farming are unlikely to reach the levels of, for example, beef farming, it is important for the industry to consider ways to reduce emissions, which can 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.

“Feed is the main source of emissions in most systems, so some of the reduction can be achieved before we even get to the fish farm, in the production of feed materials.”