How to eat seafood sustainablyScience Communicator, PhD Conservation Science
Using the power of your plate.
Fish – and how we currently catch and consume it – has become a hot topic. Blockbuster documentaries and social media campaigns have amplified what scientists have been trying to tell us for years: we are depleting our oceans.
As awareness builds, more and more people are critically evaluating their own daily choices. Can we still justify eating seafood? What is ‘sustainable’? Some people argue that the most sustainable way of eating seafood is to not eat it at all. But for many this isn’t a viable option. Individuals, communities and nations around the world rely on fish and other marine life as a healthy and affordable source of nutrition. Many people, including those in developing nations, also depend on fishing as a livelihood. The answer isn’t quite as simple as putting a stop to all fishing. But the switch to sustainable fisheries is also complicated and will require cooperation from governments, corporations, local businesses and citizens like you and me.
So where to start? There is so much information out there about sustainable seafood that it can be a little overwhelming. But there are some pretty easy steps we can all take. They may seem small, but remember: our individual actions are incredibly powerful when we all act together. It all starts with educating ourselves about what’s going wrong in the first place.
What makes our diet unsustainable? – overfishing
You have probably heard the phrase ‘There’s plenty more fish in the sea’. The problem, though, is that there isn’t. According to the United Nations’ Food and Agriculture Organization (FAO), 90% of our fish stocks are said to be overfished or overexploited, which means that they are close to collapsing. Large species that were once commonplace, such as Atlantic cod and bluefin tuna, have declined dramatically. And as these larger species disappear, other smaller species are targeted by fisheries to keep up with demand, which is known as ‘fishing down the food chain’. In reality, there are fewer and fewer fish in the sea, a situation that scientists unequivocally put down to overfishing.
Essentially, overfishing occurs when we remove fish from the sea faster than they can reproduce; in other words, the individuals we take are not replaced. This means the fishing is unsustainable, as the population cannot replenish itself and will eventually die out. Humans have fished for thousands of years, but not to the extent and scale that we see today. In the past few decades, demand for seafood has grown rapidly as have technological advances, leading to the industrialisation of the fishing industry. We have larger, more powerful fishing fleets and greater manpower. We also have fishing methods that enable us to catch huge numbers of fish in one go or harvest vast quantities of shellfish with relatively little effort.
How do different methods of fishing impact the environment?
The methods used for fishing vary widely. Some more ‘traditional’ methods, like spearfishing and rod-and-line, have been around for thousands of years. These are considered more sustainable forms of fishing, as the number of fish captured is usually small and specific species can be targeted. The use of nets, enabling fisherpeople to catch larger quantities of fish, also dates back centuries.
More recent methods follow the principle of ancient practices but industrialise them. For example, longlining involves setting a length of line (which can be miles long) in surface waters, attached to which are thousands of baited hooks. So it uses the same principle as a baited fishing rod but is designed to capture much more fish. Another example is gill nets, which are panels of net that hang vertically in the water and act almost like a giant underwater fence, intercepting species like salmon as they swim past.
These methods do allow for more seafood to be captured more efficiently, which obviously has benefits for the fishing industry and those that work within it. But they can also be very destructive. Longlining and gill-netting are non-selective, which means that non-target species can also get caught unintentionally. This is known as by-catch and it is a huge problem affecting marine life globally, including turtles, dolphins and numerous shark species. Another method is bottom trawling, where wide nets (sometimes as large as football fields) are dragged across the seafloor to catch bottom-dwellers like hake and sole. Tearing through vital marine ecosystems such as reefs, they destroy the benthic habitats in their wake. There are even some methods that use explosives! Blast fishing involves lighting sticks of dynamite to stun large numbers of fish, which as you can probably imagine has devastating consequences for the surrounding habitat.
Unsustainable, industrial-scale fisheries not only have an environmental impact but have a human cost too. Smaller-scale fisheries and local communities often lose out, as their stocks disappear and more traditional methods become economically unsustainable. This will disproportionately affect the poorest coastal nations and peoples. If we continue to fish at our current rate, the outcome will not be good for people or the planet.
Can it be sustainable to eat fish/seafood?
The short answer is, it depends. Seafood can be sustainable, provided that:
- Fisheries are appropriately and adequately managed and monitored to avoid overfishing, according to the best available science;
- The fishing methods used avoid by-catch and are not environmentally destructive;
- Policies support sustainable and ethical fisheries management;
- Governments commit to enforcing fisheries regulations and combating illegal activities;
- Consumers make careful and conscious decisions about the fish they eat, choosing seafood from well-managed, sustainable fisheries.
Getting all this right is tricky. The planet’s oceans occupy a vast space, most of which is classed as ‘high seas’, or international areas that do not belong to one particular nation. Therefore often more than one nation, with competing interests and needs, have to come to an agreement on how best to manage fish stocks. It’s a challenge – but not impossible. For example, the 52 countries of the International Commission for the Conservation of Atlantic Tunas (ICCAT) agreed in late 2021 on a retention ban to protect shortfin mako sharks, a species that has been teetering on the brink of extinction as a result of intense fishing pressure.
But while many of these decisions are out of the hands of regular citizens, we can make sustainable choices about what ends up on our plate.
How do I know if my seafood/fish is sustainable?
Making a decision about whether your fish or seafood of choice is sustainable or not can feel like a minefield. But there are some key questions you can ask:
What species is it? This may sound obvious, but knowing exactly which species you’re buying is key. There are lots of free online resources that can give you an idea of which species are okay to eat and which to avoid (for example, the WWF seafood guides or MCS Good Fish Guide). Be aware that some species can be mislabelled. For instance, in fish and chip shops, the names ‘rock salmon’, ‘huss’ and ‘flake’ are all used to label a small species of shark known as a dogfish! The rule of thumb is, if you’re not sure, don’t buy it.
Where did it come from? This means not just in terms of the region, but also the fishery. This can be a grey area, but some fisheries have been associated with human rights abuses and illegal activity and/or are considered unsustainable. A quick Google search should help you out. Whether buying from a grocer or ordering from a restaurant, make sure you ask where they source their fish if it isn’t already clearly labelled. Generally, it’s best to buy local. Not only does this support your local fishers, but it has a smaller carbon footprint and is often cheaper, too. Plus, it’s easier to find out exactly where your fish came from and…
How was it caught? You’ll often see this information on packaging or written on the menu of good restaurants (a good fishmonger should also be able to tell you). Generally, pole-and-line and rod-and-reel (sometimes also known as ‘line-caught’) are more sustainable and less damaging. When it comes to shellfish, hand-dived or hand-harvested is often the more sustainable choice.
Get used to researching and asking for this information. It can be difficult to find sometimes, but a little effort goes a long way. Again, a safe bet is,** if you don’t know, don’t buy**.
How and where should I buy sustainable seafood/fish?
The best places to buy sustainable seafood will depend on where you live and the choices available to you. But if possible, the best option is to buy local and seasonal. Find your local fish market, where you can chat directly with the people who caught your seafood and tell you exactly how they did it (this makes asking the questions in the previous paragraph 10 times easier!).
Another good tip is to find a good fishmonger. These are the people who know what’s in season and how the fish has been caught and they are likely to have sourced their fish locally. They’ll also be able to recommend different species to try, which brings me onto my next point: finding alternatives. The most popular species, and the ones we’re most comfortable with, are often the most exploited. But you can sometimes swap your favourite for a more sustainable alternative. This will again depend on where you are in the world – but there are online resources to help you make your decision.
If your most viable option is the supermarket, the best thing you can do is make sure you know a) where the fish came from and b) how it was caught. There are also some internationally recognised labels and certifications that can give you a better idea of the most sustainable option.
What should we look for in terms of labels or certifications?
One of the most broadly applied certifications is the Marine Stewardship Council (MSC) blue label, which appears on tens of thousands of products around the world. To be MSC certified, fisheries have to go through an independent assessment, carried out by scientists, that ensures they meet the MSC standard for environmentally sustainable fishing. The fisheries are also audited annually to make sure they maintain these standards. Another similar labelling system is Friend of the Sea (FoS).
However, treat these labels with caution. It’s easy to assume that an eco-label represents total sustainability, and while they do represent better practices than average and buying certified seafood is almost always better than not, seafood is not necessarily completely sustainable because it has a label. Where possible, it’s best to combine the label with knowledge of where the food came from and how it was obtained.
Should I buy farmed fish instead?
Aquaculture, or farming fish, is often touted as a viable option to replace wild-caught fish. While it does in some way avoid the problem of overfishing, it comes with other environmental concerns, including habitat degradation and pollution due to the use of chemicals and excess nitrogen from concentrated fish waste (the result of lots of fish stuck in one space!). Additionally, other smaller species of fish are caught in large numbers to feed some farmed varieties, contributing to the overfishing problem. So the answer is a lot more nuanced than a simple yes or no. Until practices have improved, it’s hard to say whether farmed fish is a viable alternative.
Should I stop eating fish?
Renowned marine scientist Dr Sylvia Earle recently suggested that people should abstain from eating seafood until we have figured out how to capture it sustainably. And this does make sense – if you can, the easiest way to reduce pressure on seafood stocks and prevent large-scale issues like by-catch is to avoid seafood entirely. You can get many of the health benefits, like omega-3 fatty acids, from plant-based sources.
So, giving up seafood is an option – just not an option for everyone. The best alternative is to be a conscious consumer: know exactly where your seafood came from, how it was caught and buy locally and seasonally wherever possible.
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