The Marine Diaries

View Original

Aquaculture: Why we Must Stop Feeding Wild Fish to Farmed Fish.

Sophie McDonald

Aquaculture has been heralded as a sustainable alternative to conventional fishing, but when billions of fish are taken from the wild every year to feed these fish farms, how can this be the solution? A new report has found that many of the fish found on our supermarket shelves have been fed wild fish, further contributing to overfishing. We spoke to Rachel Mulrenan from Changing Markets to find out how the top 10 UK supermarkets are failing to protect our oceans.

Open water fish farms. Photo: Corin Smith.

Hi Rachel! Tell us a bit about Changing Markets and the Fishing the Feed campaign. 

The Changing Markets Foundation is a global campaigning organisation working on corporate-focused campaigns. We believe that solutions to environmental and social challenges exist, but that companies need to get better at putting them into practice. Our Fishing the Feed campaign exposes the high environmental and social costs of using wild caught fish to feed farmed fish.

Aquaculture, or fish farming, is increasingly being positioned as a sustainable way to provide protein for a growing global population, without placing further pressure on already depleted wild fish populations. However, every year billions of fish - one-fifth of global catches - are taken from the wild for use in the booming aquaculture industry, and livestock rearing. Our campaign highlights how the use of wild fish to feed farmed fish and seafood is stripping the oceans bare and taking a key source of protein away from some of the world’s poorest communities.

You recently released the Caught Out report, which shines a light on the top 10 UK supermarkets and scores their level of ocean sustainability.  What were your key findings and was there anything that you found shocking?

Our report, which was published in partnership with Feedback, found that UK supermarkets are failing to properly set supply chain standards to reduce the impact of farmed fish diets on the health of wild ocean ecosystems. Of the 10 supermarkets in the ranking, just 1 (Tesco) scored higher than 50% on our scale. A total of 7 out of the 10 scored less than 30%, with discount retailer Aldi scoring just 12%. 

This means that UK supermarkets still have a long way to go to ensure their aquaculture supply chains do not harm wild fish. We have calculated that on average, UK shoppers buying the top 6 farmed fish species in 2019 unknowingly ate a ‘hidden’ 172g of wild fish for every 100g of farmed fish eaten, because of the way farmed fish are fed. We think most UK shoppers would be shocked to hear that they indirectly consume thousands of tonnes of wild fish by eating farmed seafood fed on fishmeal and fish oil (FMFO).

While it’s encouraging to see that a number of retailers have developed policies on aquaculture, in many cases there are huge gaps in these policies, or the policies are not binding. We found that not one retailer currently has a time-bound target to eliminate farmed seafood fed on wild-caught fish – that needs to change.

The Caught Out campaign’s Supermarket Scorecard ranks supermarkets on their efforts to tackle the use of wild fish in their aquaculture supply chains. Photo: Changing Markets.

Do you believe that the general public currently understands how seafood is making its way from our oceans to their plate?

The global aquaculture supply chain is highly complex and opaque. It is truly shocking that we are told so little about the origin of the farmed seafood we eat. As part of our research for this report, we conducted in-store investigations to assess how retailers are promoting farmed fish to their customers. Across the board we found a lack of accessible information for customers regarding production methods and provenance – for example, in one supermarket we found the country of origin was listed as three countries. This is not transparent labelling! 

In many cases it was not easy to tell if the fish was farmed – although wild-caught fish was clearly labelled as such. This lack of transparency makes it difficult for shoppers to know the story behind the fish on their plate. With 70% of UK shoppers keen to buy sustainable fish, retailers have a duty to clearly communicate to their customers where their fish has come from, as well as (in the case of farmed fish) what the fish has been fed with.

Are we connecting the dots between our seafood and the oceans? Photo: David Townsend (Unsplash).

What are your hopes for the future? 

Our report calls on UK supermarkets to phase out the use of fishmeal and fish oil sourced from wild-caught fish in their aquaculture supply chains by 2025 at the latest. In addition to this, supermarkets should commit to offering a wide range of seafood – including a greater diversity of sustainably caught wild fish and farmed seafood that doesn’t rely on wild fish in its feed, such as mussels.

We are also calling on retailers to reduce their reliance on flawed third-party certification schemes, such as the Marine Stewardship Council (MSC-certified). We urge them to develop their own robust and transparent standards for assessing sustainably produced seafood. The still-unfolding coronavirus pandemic has brought into sharper focus issues surrounding food production and food security around the world. Food retailers have benefited from record sales as a result of lockdown buying. As we emerge from the greatest public health crisis in living memory, we want them to use their market power to positive effect by driving change towards fairer and more sustainable food systems.


If you’ve enjoyed this interview with Rachel Mulrenan, follow her here @RachelMulrenan. You can find out more about Changing Markets here, and find their Fishing The Feed reports here.

Want to be interviewed for us? Check out our ‘Get Involved’ section.

Rising Tides is a series focussing on the current threats facing our ocean, how these are being tackled and what you can do to help