Is There Such a Thing as Sustainable Fishing?

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Globally, seafood represents 15% of animal protein consumed by humans, and the fishing industry employs around 35 million people world wide. Fish are big business, but not for long. That business is set to vanish in the next few decades, unless we make some major changes. Massive cuts to global fishing quotas and to our consumption of fish are necessary if we are to avoid totally eradicating all remaining edible fish in the space of a generation. The loss of our fish would be catastrophic – millions of people unemployed, millions of people without adequate nutrition, a collapse of the ocean ecosystem and the loss of many crucial ecosystem services. It may even make global warming worse, too!

But for us consumers, what can we do? Is there any way to sustainably include fish in our diets?


SustainableFishing002The problems with the fishing industry are many. For starters, we’ve been overfishing our seas to a horrific extent for the last 50 years or so – since we invented technology that allowed us to really dominate the ocean environment. Three quarters of the world’s fish stocks are being over harvested and exploited beyond their capacity to recover, and 80% are in decline or worse. If fishing continues at it’s current pace, world fish stocks are predicted to collapse totally by 2050.

This is a very serious issue indeed. It is estimated that a fifth of the world’s population depends on fish as their primary source of protein – what will these people do when once we’ve eaten all the fish?

The world’s stocks of large, predatory fish (e.g. tuna, cod, halibut, swordfish, shark) have been particularly badly hit, with 90% of their populations now gone. Despite this, illegal fishing continues and it is estimated that in 2010, 97 million sharks were killed, weighing 1.4 million tons. Catches between 2000 and 2010 represented an exploitation rate of around 7%, significantly higher than the reproductive rate of many of these species (~5%).

Not only are commercial fish stocks declining, but many of the industrial fishing practices that have enabled us to take such advantage of the seas (e.g. trawling), have a shocking impact on the ocean ecosystem as a whole, and research suggests that ecosystems are very slow to recover from these damaging fishing practices even after they’ve stopped. It is thought that 95% of damage to seamount ecosystems (damage that is visible from space, by the way!) is caused by deep sea bottom trawling.


Atlantic Bluefin Tuna

Blue Fin tuna is a famous cautionary tale. For centuries we fished Atlantic bluefin tuna (Thunnus thynnus). These enormous predatory fish provided generations of people with a plentiful food source. And as our technology improved, so did our catch of bluefin tuna. But eventually, rather than increase, global catches started to decrease. The seemingly endless tuna stocks were gone. Bluefin tuna are now one of the most endangered fish in the world. Catch limits have been in place for bluefin tuna since 1998, and in 2006 the International Commission for the Conservation of Atlantic Tunas (ICCAT) established a 15-year recovery plan. However, as fishing quotas continue to be broken, many remaining populations are predicted to crash and may go extinct. A stock assessment in 2013 estimated that 96% of Bluefin Tuna stocks in the Northern Pacific Ocean have now been lost, with the increasing rarity of this fish reflected in astronomical prices in Japanese auctions (a single tuna sold for £1 million last year!). It is thought that many of the fisheries that continue to catch Tuna are keeping some of it back, frozen, in anticipation of souring prices when the species becomes extinct in the wild. It is still too soon to tell, but intial reports this year suggest that strict quotas and management of Mediterranean bluefin tuna stocks may be yielding dividends already – in June a Spanish fleet caught it’s entire quota in just 48 hours, leading some to speculate that the fish stocks in this area are beginning to recover and that quotas may be increased again. We must proceed with extreme caution, however. Bluefin tuna are not out of the woods yet.


It isn’t simply that we’re eating too many fish, the fishing industry is also disgustingly wasteful. Bycatch, fish and other creatures that are caught by mistake whilst fishing for another species, usually is discarded back into the ocean – dead, dying or incapacitated, rarely with any hope of survival. Estimates suggest that as much as 8 – 40% of global marine catches are discarded as bycatch, including fish, whales, dolphins, porpoises and sea turtles. Trawling is particularly bad for bycatch, and shrimp trawling probably the worst – responsible for 1/3 of the world’s bycatch to produce just 2% of the seafood we eat! Even when we set fishing quotas and police them well, the fish species subject to quota may continue to be caught as bycatch long after the legal quota has been reached – since these fish are illegal they are generally thrown back which is obviously extremely wasteful and diminishes any benefits of fishing quotas in the first place.

Legislating Greed

SustainableFishing005The amount of fish people are legally allowed to catch each year is supposed to be controlled by fishing quotas imposed at the international level. These quotas should be set based on the real, uncompromisable biological limits of nature – quotas should be set below the carrying capacity of the environment. This isn’t the case, of course, because quotas are also a political matter. They are consistently set too high for long-term sustainability, and regardless, the quotas are so poorly policed that it is estimated that actual catch may be nearly double the quotas for some species.

Some might argue that the situation is complex on account of the number of people whose jobs depend upon the fisheries industry. This, for me, is a non-point, really. If we continue to fish the way we are, there will be no more fish in a couple of decades, and all those people will be out of a job for good. So when a fisherman complains that reducing fishing quotas would damage his (or her!) livelihood, it seems to me to be the exact opposite. Only with sensible fishing quotas and strong control of fishing will the fisheries industry be able to continue at all.

Fishing subsidies are a major issue in the battle against unsustainable fishing. Many governments offer their fishermen subsidies to enable them to fish for longer and further afield than the would otherwise be able to afford, and many high-sea fishing operations would not be economically viable without them. Global fishing subsidies amount to between $15 and $35 billion annually, in the form of cash grants, tax breaks, loan guarantees and the provision of goods and services. Although some of these subsidies go towards trying to reduce fishing fleets and combat overfishing, the majority are contributing to the problem, not the solution. You can find out more about who is getting what subsidies in the EU at the FishSubsidy.Org database.

Farming Fish

One obvious alternative to eating wild caught fish, which many people seem to have concluded is guilt-free, is farmed fish. Fish farming is becoming increasingly big business, with carp, salmon, tilapia and catfish most commonly being farmed. Fish and shellfish are environmentally friendly in some ways – they emit fewer green house gases than cows and some species are very efficient at turning feed into edible protein, making them a potentially green source of protein. However, many farmed fish species require large quantities of wild fish to eat and the waste from crowded aquacultures is ultimately released into the sea as a pollutant. Crowded conditions also breed disease and these diseases can easily be transferred to wild populations. Unfortunately, the most expensive farmed fish we like to eat, such as salmon, tends to be the least efficient. Estimates for how much fish meal is used to feed farmed fish vary wildly, from 0.5kg of feed per kg of fish to as much as 22kg of feed per kg! In reality, the efficiency varies greatly between species and different species, but estimates suggest that 30% – 50% of the global annual fish catch is used to feed farmed fish. Farmed fish, therefore, is hardly a perfect solution.

Research is ongoing into the best ways to improve efficiency and reduce the environmental damage caused by fish farming. For example, some salmon farms in South Africa have trialed feeding their salmon on fly meal rather than fish meal. Scientists at The Institute of Marine and Environmental Technology (IMET) have gone further, and are currently developing a totally clean, environmentally friendly, indoor aquaculture system which recycles it’s own water using bacteria. They’ve also been working on fish meal made from grains, algae and amino acid supplements as a replacement for fished feed. Fish like this would have a minimal environmental foot print, but it’s not on our plates just yet.

If you’re going to eat farmed fish, the best thing you can do is east small fish that are low on the food chain such as catfish and carp, as they are unlikely to have been fed other fish. Molluscs such as oysters and scallops are a very environmentally friendly source of protein (as are insects, actually…), and in general shellfish, being filter-feeders, are relatively sustainable and green. RSPA Freedom Food certifies farmed fish products that meet their welfare standards, and their label can be easily found of food packaging. Remember, though, these criteria consider the welfare of the fish, and do not include the environmental impact of the farms they come from. In several cases, fisheries that are Freedom Food certified have been accused of very poor environmental practises including ocean pollution and lice infestations.

Sustainable Fisheries

The Marine Stewardship Council (MSC), a partnership between Unilever and WWF, assess and certify fisheries as sustainable, and their symbol can be found clearly on food packaging. You can also check this list of MSC certified fisheries worldwide. The MSC certification is based on 3 principles: 1) a fishery must not over-fish or cause depletion of populations, it must allow depleted stocks to recover and it must not alter the age, genetic or sex composition of the population so as to impair reproduction; 2) fishing operations must maintain the structure, productivity, function and diversity of the ecosystem on which the fishery depends, maintain functional ecosystem relationships, and enable damaged ecosystems to recover within a specified time frame; 3) a fishery must be managed so as to respect local, national and international laws and standards, it must demonstrate clear, long-term objectives in accordance with MSC principles, and be appropriate to the cultural context, scale and intensity of the fishery. Together, these criteria hope to ensure that sustainable fisheries maintain and nurture the ecosystems upon which they rely to maintain the resource in the long-term. You can find out if the brands you like are MSC certified here.

Unfortunately, the MSC certification system has been heavily criticised by scientists and conservationists that claim some of the fisheries within the scheme are still exploiting fish stocks and acting unsustainably. For example, the Ross Sea Antarctic Toothfish fishery is MSC certified despite limited scientific understanding of the biology of the Antarctic Tootfish, and recent evidence to suggest a major ecological impact of this fishery. Since it’s inception in 1997, conservation organisations have filed 19 objections to MSC fisheries certifications, one of which has resulted in certification being revoked. Some of the largest MSC certified fisheries have been the most contentious, with 35% of the total weight of MSC certified fish subject to at least one objection. Many feel that the criteria of the MSC are too lenient.

If you’re in the US, you can check out GreenPeace’s latest review on sustainable fish products in supermarkets, which reports improvements in many of the major brands. The Sustainable Fisheries Partnership (SFP) has also created a database of fisheries which includes sustainability assessments and suggested improvements; this data is accessible to all at FishSource. The database now includes over 1000 fisheries worldwide and includes scientific data from governments, academics and other groups on the sustainability and impacts of these fisheries.

Marine Protected Areas

Marine protected areas (MPAs) form a crucial part of the recovery of our oceans. Within MPAs fishing is prohibited and this has been shown to increase fish stocks within protected areas as well as creating a spillover effect into neighbouring waters. MPAs therefore can improve fishing catches, and can act as a ‘savings account’ for our fish. Effectively implemented and managed MPAs harbour five times as much large fish biomass and fourteen times more shark biomass than fished areas.

SustainableFishing006Currently, around 2% of the world’s oceans are part of a Marine Protected Area, safe from fishing activities. Scientists suggest that we should be committing around 20 – 40% of the seas to MPAs, and recently, many coastal nations have committed to increasing MPAs in territorial waters to 10% by 2020. However, even those MPAs we already have are not all being managed and policed well enough to be anything more than ‘parks on paper’ – estimates suggest that less than a third of MPAs are appropriately enforced. Further, many parks are small and only recently created, meaning their conservation value is limited and it will take time for their benefits to be evident.

In a recent comprehensive assessment of nearly 90 MPAs, researchers evaluated the impact of five key features on MPA effectiveness: protected, enforced, protected for more than 10 years, size larger than 100 km2, and isolated. Their conclusions were startling. Conservation value in MPAs matching less than 3 of these criteria (60% of MPAs studied) was essentially zero – these MPAs were indistinguishable from fished sites. Conservation value increased exponentially when 4 or more criteria were met, but only around 10% of current MPAs fall into this category.

It has been estimated that it would take between $5 and $19 billion each year to police a network of MPAs covering 20 – 30% of the World’s oceans. It would create an estimated 1 billion jobs in the process. That is roughly the annual spend on fishing subsidies… Convenient, that, eh?


It is actually surprisingly difficult to measure any recovery in the World’s oceans, and different statistics measure slightly different metrics and yield different results. So far, the data suggests that the recovery of the oceans is not occurring uniformly across the globe. In Europe, North America and Oceania, fish biomass is in a state of stabilisation, with populations stabilising at a level below sustainable levels. With reductions in exploitation, these populations have the potential to recover over time. By contrast, the rest of the world is thought to have larger, but declining fish populations. Fishing here is less controlled, data is poorer and management targets are difficult to set and assess. The picture is still murky, and a lack of data is a real problem. Much of the global catch comes from developing regions, where jobs and food are desperately needed, but where the infrastructure to allow for scientific assessment and effective management is limited. These regions are also often the most biodiverse and many are considered to be conservation hotspots. It is crucial that we invest in stock status reports for species in developing regions.

Progress is being made towards more sustainable fishing practices, but we still have a long way to go. There are major gaps in our knowledge and understanding of many fish species and the ecosystems they occupy, but we have sufficient data to be sure that for the vast majority of commerical fish species, at least, our demands exceed the capacity of the oceans and we must consume less wild fish if we are to avoid complete decimation of our oceans. However, evidence suggests that there are solutions at our disposal; biologically-based, well enforced fishing quotas can allow depleted populations to recover; well-designed and managed marine protected areas can allow damaged ecosystems to bounce back and could act as a savings account to feed neighbouring fisheries. Current measures to try and reduce overfishing, improve sustainability and importantly, certify sustainable fish to enable effective consumer choice are a massive improvement on the situation even a decade ago. Improvements in the efficiency and environmental impact of farmed fish may help to ameliorate the situation, but farmed fish is currently far from sustainable. Conserving the World’s oceans is critical if we are to manage our own food security issues, but also to continue to allow communities in developing countries to access a food source they so desperately depend upon.

Want to Know More?

Watch this clip from the documentary film The End of the Line, or get the full version here.

  • National Oceanic and Atmospheric Administration – Feeds for Aquaculture
  • The Marine Ingrediants Organisation – How many kilos of feed fish does it take to produce one kilo of farmed fish, via fishmeal and fish oil in feed?
  • MSC Fishery Standard: Principles and Criteria for Sustainable Fishing
  • Save Our Seas: Overfishing
  • Charles (2014) The Future of Clean, Green Fish Farming Could be Indoor Factories. The Salt
  • Edgar (2014) Global Conservation Outcomes Depend on Marine Protected Areas with Five Key Features. Nature 506: 216 – 220
  • Halpern (2014) Conservation: Making Marine Protected Areas Work. Nature 506: 167 – 168
  • Ainley et al (2013) Decadal Trends in Abundance, Size and Condition of Antarctic Tootfish in McMurdo Sound, Antarctica, 1972 – 2011. Fish and Fisheries 14: 343 – 363
  • Carrell (2013) Freedom Foods ‘Failing to Crack Down’ on Poor Salmon Farming Standards. The Guardian
  • Christian et al (2013) A Review of Formal Objections to Marine Stewardship Council Fisheries Certifications. Biological Conservation 161: 10 – 17
  • Harvey (2013) Overfishing causes Pacific bluefin tuna numbers to drop 96%. The Guardian
  • Worm et al (2013) Global catches, exploitation rates and rebuilding options for sharks. Marine Policy 40: 194 – 204
  • Harvey (2012) EU fishing quotas defy scientific advice, say conservationists. The Guardian.
  • Althaus et al (2009) Impacts of bottom trawling on deep-coral ecosystems of seamounts are long-lasting. Marine Ecology Progress Series 397: 279 – 294
  • Worm and Branch (2012) The Future of Fish. Trends in Ecology and Evolution 27(11): 594 – 599
  • Smith (2011) Sustainable fish customers ‘duped’ by Marine Stewardship Council. The Guardian
  • Davies et al (2009) Defining and estimating global marine fisheries bycatch. Marine Policy
  • Greenpeace (2009) Assessment of the Marine Stewardship Council (MSC) Fisheries Certification Programme
  • UNEP (2008) Fisheries Subsidies: A Critical Issue for Trade and Sustainable Development at the WTO. An Introductory Guide.
  • Cummins (2004) The Marine Stewardship Council: A Multi-Stakeholder Approach to Sustainable Fishing. Corporate Social Responsibility and Environmental Management 11: 85 – 94
  • Balmford et al (2003) The Worldwide Costs of Marine Protected Areas. Proceedings of the National Academy of Sciences USA 101(26): 9694 – 9697

2 comments on “Is There Such a Thing as Sustainable Fishing?

  1. Thank you for your very informative post Claire. Your recommendations in the final paragraph would surely ensure that our oceans thrive in the future. I’d add controls on the type of fishing allowed, which you do explain in your post; the damage from bottom trawling and scallop dredging is very worrying.

    The EU did finally move in the right direction with the Common Fisheries Policy last year, but only after strong campaigning by Hugh Fearnley-Whitingstall and his Fish Fight Campaign, aided by some British MEPs who worked tirelesly on the issue only to get rewarded with losing their seat at this year’s EU Parliamentary Elections. MEPs were bombarded with emails demanding reform in the run up to the vote, and change occurred.

    It is easy to expect everyone else to save the planet for us, but really each one of us has our own responsibility. To take responsibility we need to be aware of the consequences of our purchasing decicions. Posts like this help us all make the right choices. I have cut down on fish / seafood and have purchased MSC only products for some time now. The real reservation I have with MSC is that it can feel safe to eat fish as long as the label is present, when in fact it is not a 100% guarantee. That said if enough of us express our concern whenever fisheries not complying with the the MSC rules are highlighted, then the scheme will continue to gain credibility.

    [Comment migrated from Google+ comments:

  2. As the study “The Tragedy of the Commons” suggests, there can never be really sustainable fishing on the “high” seas as these are “commons” in the sense that everyone can profit but no one pays a price (except for equipment. And as with tax laws, it is in human nature to try and find always the next loophole in any regulation. That very same inventiveness could surely be turned to good use in fisheries (as anywhere else, q.v. the enormous progress made in computing), if the fishery grounds were not kind of “common property”. Maybe just something like an “International Guild of Fishermen and Seafarers” to whom the rights to the oceans were turned over for a lease to the international community might already do the trick. (Of course, like on roads, the public would still be given free access to travel etc.).

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