THE LOW ENVIRONMENTAL IMPACT OF SHELLFISH (AND THE FUTURE OF AQUACULTURE)

The low environmental impact of shellfish (and the future of aquaculture). Could pescetarianism be the new veganism? Here, Barry Crackett, from specialist industrial and farming brushware supplier Brushtec, outlines the low environmental impact of shellfish farming.

While global carbon emissions dipped during the pandemic, numbers remain at an all-time high (IEA). As a result of the environmental crisis, 12% of the UK population intend to switch to a meat-free diet in 2021 (Finder), as more people become aware of the environmental impact of their eating habits. Vegetarianism is currently top of the list, with around 6% of Brits following this diet. Closely following is pescetarianism, with 5% of Brits forgoing meat but still eating fish.

This is great news for shellfish farmers, but as consumers focus more on the environmental impact of their food, the pressure is on for producers to up their eco credentials. 34% of consumers say they support brands that have environmentally sustainable practices, and 55% say they choose sustainable brands for their grocery shopping. Meanwhile, 28% say they have stopped purchasing from certain brands due to ethical or sustainability concerns (Deloitte).

Luckily, for those following a pescatarian diet, shellfish already has a low environmental impact. Below, I’ll be outlining a few of the reasons why, as well as how the future looks for shellfish farming and the environment.

It has a lower carbon footprint

When compared with other farming methods, especially cattle farming, shellfish farming (aquaculture) has a significantly smaller carbon footprint. Bivalves such as oysters, mussels, clams, and scallops produce just 11.1 tonnes of greenhouse gas emissions, according to a report published in the journal Nature Food. Compared to the 57.6 tonnes produced by pork, and 337.2 tonnes produced by beef, shellfish has a much lower environmental impact.

Shellfish can reduce nitrogen levels

Not only does shellfish farming produce fewer greenhouse gas emissions, but it could actually help benefit the ecosystem. For example, nitrogen is vital for maintaining plant life, but sometimes excess nitrogen from land farming can enter the sea through runoff (in a process called eutrophication). This can reduce oxygen levels and harm sea life.

Luckily, shellfish can help regulate nitrogen levels by filtering the water. Bivalves actually have a negative eutrophication potential of around -148, according to the Nature Food report. This means they won’t add excess nitrogen to the water, but will remove it instead. On average, most adult oysters can filter nitrogen from up to 50 gallons of water every day as they feed (WHOI). Then, once the shellfish is harvested, this excess nitrogen is removed from the water completely.

They can boost biodiversity

As well as maintaining oxygen levels in the sea, aquafarming could also help provide a more viable habitat for other forms of sea life. As a result of their feeding and filtration processes, shellfish can help improve water quality, which can make it more habitable for sea grasses on the seabed. Other organisms rely on these grasses for shelter, making it a great place for fish and invertebrates to live and breed. It’s no wonder scientists have labelled these areas as ‘hotspots for biodiversity’.

The future of shellfish farming is bright

As a result of population growth, producers need to scale up their farming to meet demand, and many organisations are looking into the ways we can grow shellfish farming in the future. It’s estimated that global aquaculture production could more than double by 2050, according to a report from the World Resources Institute, as the majority of the fish we will consume is expected to come from farms. And, considering most shellfish farms are located in developing countries, this growth could help to raise employment levels and income in areas that need it the most.

As aquaculture grows, farmers also need to work out how to raise their production levels without negatively impacting the environment. One of the biggest sustainability issues facing the sector is the availability of ocean space. Already at a premium, producers need to find even more farming areas, without sacrificing vital ecosystems.

Perhaps one of the most popular methods of growing farming sustainably is by moving to offshore farms, where space is more available. The biggest form of offshore farming includes cultivating rope-grown mussels, which provides all the benefits of shellfish farming and takes a low amount of fuel and energy to harvest. This is largely thanks to recent innovations that make offshore farming possible, and efficiency can be improved even further with the implementation of special technologies, such as mussel farming brushes. These will help farmers harvest, separate, and clean rope grown shellfish much more quickly than before, increasing output to meet rising demand.

These are just some of the ways shellfish farming can benefit the environment. If you’re looking to make more conscious food choices, then eating more shellfish could be the solution.