What is sustainable fishing?

Fishing is sustainable if enough fish are left in our oceans and impacts on marine habitats and ecosystems are minimised. For this to happen, fisheries must follow sustainable fishing practices and be managed effectively.

Communities around the world - including here in the UK and Ireland - rely on fishing for their livelihoods and as a vital source of food and nutrition. More than a third of the global population relies on seafood as a source of protein and 38 million people are employed in wild capture fisheries.

Across the UK and Ireland, fishing is central to coastal communities, supporting jobs, local economies and a shared cultural heritage. In 2024, UK vessels landed around 745,000 tonnes of seafood worth £1.16 billion, underlining the sector’s importance as both a food source and economic driver.

However, unsustainable fishing practices, such as overfishing, unregulated fishing activities and excessive bycatch, are putting our oceans at risk.

Sustainably managed fisheries help secure this future. From Scottish herring fisheries that have recovered from historic collapse, to shellfish fisheries in places like Shetland and the Thames Estuary, there are clear UK and Irish examples of how environmentally sustainable practices can rebuild stocks and support livelihoods for generations to come.

Why do we need sustainable fishing practices?

Overfishing is when too many fish are caught and there are not enough adults to breed and sustain a healthy population. This means the stock is overfished. To combat the devastating effects of overfishing on the environment and the economy, we need to implement sustainable fishing practices. 

 

Stay informed on overfishing

How can fishing be sustainable?

Stock assessment

Scientists work out how many fish can be safely caught without impacting the future health of the stock. This involves collecting data on the size of the stock, when and where the species spawns and how many juveniles are likely to survive into adulthood. They also assess environmental factors that may affect the stock, such as predation from other species.

Management policy informed by science

Different management measures can also be implemented to protect stocks from overfishing, such as prohibiting fishing during spawning seasons and setting size limits to protect juveniles.

Harvest control rules

A key aspect of sustainable fishing also involves adopting precautionary measures known as harvest control rules, which require catches to be reduced if the stock population declines. This is particularly important when stocks are shared by several different countries and a collective effort is needed to prevent overfishing.

Fish stocks are also more abundant when targeted by fisheries operating sustainably, compared with those which do not.

How does sustainable fishing protect the oceans?

Maintaining balanced ecosystems

Sustainable fishing helps maintain healthy and diverse ocean ecosystems and minimises impacts on endangered, threatened, and protected species.

All species have a unique role within ocean ecosystems and are part of a balanced food web of predators and prey. The loss of a single species due to overfishing or excessive bycatch can have a knock-on effect across the entire food web.

Regulating climate change

It’s not just fish stocks that benefit from a healthy ecosystem, it can also help the ocean regulate the climate. Carbon dioxide from the air dissolves into seawater and is trapped within different elements of the ocean ecosystem, such as seagrass, the shells of molluscs, and plant-like plankton.

Climate change is already having a significant impact on our oceans and the health of fish stocks, making sustainable fishing more important than ever.

Reducing the environmental impact of fishing is a key objective of sustainable fisheries management. This includes protecting sensitive habitats, minimising bycatch of non-target species and ensuring fishing activities do not damage the long-term health of marine ecosystems.

What is the MSC’s approach to certified sustainable fishing?

The Marine Stewardship Council (MSC) recognises and rewards fisheries operating sustainably through our fisheries certification programme and blue ecolabel.

Our Standard is the leading measure of environmentally sustainable fishing and is rooted in global best practice in fisheries management and widely accepted fisheries science.

Fisheries volunteer to be assessed against our Standard by an independent third-party and must meet these three principles:

Sustainability is about the future

The sustainability of a fishery is an ongoing process. After fisheries are certified to the MSC Standard, they are regularly reassessed and many are required to make further improvements. Scientific knowledge also improves all the time and fisheries are encouraged to develop new ways of conserving marine resources for future generations.

The Shetland crab and scallop fishery has been certified as sustainable since 2012. Working closely with Shetland UHI (previously the NAFC Marine Centre) on scientific evidence of stock management, its proactive management approach has led to some positive developments in managing and sustaining this important UK fishery. In the past decade, it has been fully reassessed and undergone a number of surveillance audits.

As ocean conditions continue to change, sustainable fishing practices will play an increasingly important role in ensuring seafood remains a renewable resource. Continuous improvement, scientific research and collaboration between fisheries, scientists and managers are all vital to the future of sustainable fishing - here in the UK and Ireland and worldwide.