Sustainable fisheries

The peace and silence that reign in the depths of the oceans are becoming increasingly unsettling. At first glance, life underwater appears to continue as normal, but behind this infinite calm lies a troubling reality: the underwater world is being emptied. The World Wide Fund for Nature (WWF) states in its Living Planet Report 2024 that freshwater species alone have declined by 85%, making the fishing industry the main threat to marine wildlife. 

What is sustainable fishing and how can consumers recognise it? 

Sustainable fishing is a practice that aims to respect the structure, productivity, function and diversity of marine ecosystems, avoiding overfishing and paying particular attention to protected, threatened or endangered species. It also promotes sound management that supports the livelihoods of fishing communities and respects local, national and international regulations. 

How can we recognise sustainable fishing? There are currently international certifications that identify whether fishing is carried out in compliance with environmental standards, such as the MSC (Marine Stewardship Council) standard, which promotes a framework for measuring progress in fishing practices.

Problems caused by overfishing

The loss of marine biodiversity also has negative consequences for the more than 3 billion people in the world who live off the richness of the seas and coasts, according to the United Nations (UN), as well as for the fishing fleets that are forced to sail hundreds of kilometres further to cast their nets in more productive waters.

These forced journeys in turn create new problems such as the overexploitation of other fishing grounds and the outbreak of territorial conflicts, especially off the coasts of Africa, Latin America, and south and north-east Asia, the continent with the greatest fishing activity in the world. In addition, the impoverishment of the seas, together with the lack of resources in the poorest fleets, encourages illegal fishing, which generates 36 billion dollars annually, degrades marine ecosystems and endangers food security.

The state of marine fauna

The Food and Agriculture Organization of the United Nations (FAO) states that 35.5% of fish stocks are overexploited, as they are not given enough time to recover after being caught. For example, the organisation reported in 2025 that overfishing in the south-east Pacific and the south-west Atlantic affects more than 45% of fish stocks in those areas. However, in regions such as the Mediterranean and the Black Sea, there has been some recovery compared to previous years. Although only 35.1% of stocks are fished sustainably, fishing pressure has decreased by 30% and biomass has increased by 15% since 2013, thanks to international cooperation and the efforts of regional governments. 

However, there is still a long way to go. According to Greenpeace, various species of tuna, hake, cod and prawns are in a situation of overexploitation, putting marine ecosystems and food sustainability at risk. 

 SEE INFOGRAPHIC: The state of the world's fisheries [PDF]

Sustainable aquaculture

Fish farming, both in coastal and inland areas, is a booming activity worldwide. The FAO considers that a sustainable aquaculture strategy is based on fair remuneration for producers, equitable sharing of costs and benefits, sustainable regulation by governments, and the creation of wealth and quality employment. This approach helps ensure food security and environmental management that benefits future generations. 

Iberdrola’s role in protecting marine biodiversity 

At the Iberdrola Group, delivering a positive impact on biodiversity is one of our strategic priorities. For this reason, we have launched a range of initiatives to protect ecosystems, including marine species. These measures are part of our Biodiversity Plan 2030, which applies a conservation hierarchy – avoid, reduce, restore and offset impacts – across all phases of our projects. This approach seeks to avoid installations in areas of high ecological value, reduce pollution and restore affected habitats.

We also carry out measurable monitoring of our impact through systems that assess effects on species and ecosystems throughout the lifecycle of our infrastructure. 

For example, at East Anglia One, the use of HVO30 fuel, made entirely from vegetable oils, reduces emissions by 30% compared to conventional marine fuel. In addition, studies are being conducted on potential acoustic impacts on marine animals to ensure their wellbeing is not affected. 

We are also working to build a better future and a cleaner, more sustainable energy model – a long-standing commitment that has made us leaders in electrical networks and renewable energy. Smart grids will help preserve biodiversity and natural resources, reducing pollution in our seas and across nature.