If you want to reduce your personal impact on the environment, reducing your consumption of animal products is one of the simplest things you can do. But going vegan and eating only plants is unlikely to be a suitable solution for everyone in the world.
Fish and other seafood are often overlooked by environmentally conscious people, but new research known as the Blue Food Assessment shows they can help tackle the twin challenges of climate change and food safety food. This year’s UN Food Systems Summit encompasses ‘blue foods’, fish, shellfish and other foods raised in water, complementing ‘green foods’, those that come from land, plants and animals.
The five research papers by more than 100 scientists led by Stockholm and Stanford Universities highlight how aquatic foods could be used in the coming decades to fight malnutrition, reduce the environmental footprint of the food system and provide livelihoods – echoing much of the other work that has been done in this area.
Growing, processing and distributing food contribute a massive proportion of the greenhouse gas emissions that are the underlying cause of climate change, while large numbers of people still suffer from malnutrition, obesity and sometimes both. Some seafood has the potential to provide people with high-value nutrition while producing relatively low emissions.
But research suggests that there are significant variations in climate impacts and micronutrient content of farmed and wild fish, which are affected by species, size and system. Scientists are only just beginning to understand this and the potential trade-offs.
The problem is that all seafood is often lumped together, making it difficult to accurately compare it to other food sources. Although we are able to draw conclusions about the best seafood we eat, the picture is usually complicated and we don’t always have all the data we need.
The most commonly farmed species around the world, including carp, trout, salmon, catfish and tilapia, have environmental impacts comparable to those of chicken, the most efficient and consumed meat – and well lower than those of beef or lamb. But how the fish are raised can make a big difference. For example, filter-feeding carp in freshwater systems have lower carbon emissions per serving, but carnivorous marine fish such as bass have much higher emissions.
More than half of the seafood consumed globally is still caught rather than farmed, and there is a significant range of carbon emissions associated with different fisheries, largely reflecting the different methods used and the abundance of stocks. Farmed fish can be made more environmentally friendly if less feed is used to produce the same amount of product consumed.
At the same time, some non-fed farmed species can also have a positive impact on the environment. For example, mussels, clams and oysters filter natural food from the water, removing excess nutrients.
There is also a marked difference in the diversity of aquatic agriculture compared to that on land. While only a handful of farmed animals (chickens, pigs, sheep and cattle) provide most of the meat consumed by humans, more than 400 species of aquatic animals are farmed today. A greater variety of foods and sources helps improve food security and spread risk for farmers. And, most importantly, this biodiversity can support more diverse and nutritious diets.
As one of the new studies points out, many species of fish and seafood are rich in important nutrients, which may give them a distinct advantage over meat with a similar or greater environmental impact. Compared to chicken, trout contains about 19 times more omega-3 fatty acids. Oysters and mussels contain 76 times more vitamin B-12 and five times more iron. And carp has nine times the calcium.
The nutritional benefits of aquatic foods are particularly important for women, who benefit more than men from increased consumption in nearly three times the number of countries studied, according to the research.
As such, seafood can be key in reducing malnutrition among at-risk groups around the world, such as children and adolescent girls. For the more affluent, replacing meat with fish can reduce the risk of poor health associated with cardiovascular and other diseases.
But again, the picture is complex. For example, small fish eaten whole are generally more nutritious than eating only fillets. Fish are often touted as healthy due to the high levels of omega-3 essential fatty acids some species contain. But the greatest dietary value will come from eating a diverse range of seafood to get a wider range of micronutrients.
Global climate challenges and fish
However, many challenges remain for seafood to realize its potential as a low-impact, highly nutritious food source for a large portion of the world’s population. To have climate-friendly fisheries, we must encourage the most sustainable development of the industry and protect the livelihoods of fishers and small-scale farmers. Incentivized fish production and trade could drive prices down, ensuring that poorer people can still afford to buy seafood as others’ incomes rise and demand rises.
But this latest research provides compelling evidence of how good fish and seafood choices can be both good for people and the planet and will be important in ensuring they become a bigger part of world food.