Eating salmon – environmentally, the best choice


Laura Braden, PhD

Over 45% of the Earth’s land surface is used for agricultural purposes, and about 75% of that land is used to raise feeds for chickens, pigs and cattle. Livestock production (including meat, milk and eggs), contributes to over 40% of the global agricultural gross domestic product and uses about one third of the world’s fresh water.

The global production of land-based meat has several serious drawbacks. For example, some recent reports have linked the beef industry with up to 50% of greenhouse gas emissions.

Cows need a lot of room, and to make this room, massive stands of global forests have been cleared. In South America alone, recent estimates suggest that 136 million hectares of the rainforest have been cleared for beef (and feed for cattle). In fact, 1-2 acres a second are being cleared in the rainforests for this purpose, leading to vast habitat destruction and subsequent species extinction.

Beef production requires 28 times more land, 11 times more water (one pound of beef requires approximately 2500 gallons of water), and produces 5 times more climate-related emissions (eg methane and carbon dioxide) than either pork or chicken production. In fact, conservative estimates suggest that livestock contributes more greenhouse gases than the entire transportation sector.

On a whole, there is no other single human activity that has a bigger impact on the planet than the land-based meat production sector.

Research has shown repeatedly that production of beef and pigs is not sustainable for our growing populations. Meat production is projected to double by 2020, and most of this increase in production will come through industrialized animal production systems. These trends will have major detrimental consequences on the global environment.

However, not all protein production is the same. And environmental agencies are starting to see that fish might represent the most sustainable option for feeding the masses.

The environmental standards organization Seafood Watch is reviewing the impact that aquaculture and fishing have on climate change and believes that the lower carbon-emitting impact relative to beef and other animal husbandry could be a marketing point for the industry.

Speaking at the Napa Seafood Summit in September, the business manager for Seafood Watch, Shawn Cronin, detailed how the beef industry has the highest carbon emissions (and thus highest impact). Cronin said that because greenhouse gas emissions form such a large part of environmental impact, Seafood Watch feels it’s worth monitoring.

Given the lower impact of seafood production, Cronin said he believes that the industry could market seafood consumption as an environmentally friendly option. “I think this really is an opportunity to show how seafood use in general. if you want to talk about environmental impact in comparison to other proteins, has a real opportunity to stand out as something that has low environmental impact when it comes to greenhouse gases,” he said.

Growing salmon is among the most resource-efficient methods of food production, as salmon (1.2 kg of feed to produce 1 kg of salmon; 1.2:1) are more than twice as efficient as pork (3.2:1) and chicken (2.0:1) at converting feed to energy. However, beef cattle (8.0:1) are incredibly poor at converting feed to energy. And this poor efficiency has a significant effect on the carbon footprint. In a study published in the journal Proceedings of the National Academy of Sciences (Echel et al., 2014), cattle – especially grain-fed ones – have a far greater demand for land, water and feed compared to either poultry or pork and thus a higher carbon footprint.

Although this study didn’t include farmed salmon in its comparison, early studies have clearly shown how salmon production has an equal, if not lower, carbon footprint than the production of land-based meat products. An independent Norwegian research group (SINTEF), showed in 2009 that the carbon dioxide footprint of salmon (Norwegian farmed-raised) at the farmgate is 6.4 lbs. The farmgate carbon dioxide footprint for beef is a whopping 66.1 lbs, while pork and chicken are 13 and 6 lbs respectively. 

A similar study conducted by Environmental Working Group and CleanMetrics Corp in 2011 also reached the same conclusions – ocean-farmed salmon are a significantly better alternative to beef.