Since 1961, the average annual increase in global fish consumption has outpaced population growth and exceeded consumption of meat from all terrestrial animals combined 1. Accordingly, fish stocks have been increasingly exploited, with 33% of fish stocks overfished and 60% fully exploited in 2015 1. Demand for fish is driven by population growth, human migration toward coastal areas, and rising incomes increasing demand for luxury seafood 1.

To identify a sustainable level of fish stock exploitation, experts use a metric called the Maximum Sustainable Yield (MSY), a threshold number of fish above which stocks are not sustainably harvested and will decline. While the metric itself has been criticised for oversimplifying complex population dynamics 2, and stocks have been commonly fished above MSY 3, an additional underlying challenge to this estimation lies in the number of fish that are removed in an Illegal, Unreported or Unregulated (IUU) way and not appropriately taken into account in stock assessments.

What are Illegal, Unreported, Unregulated (IUU) fisheries?

IUU fishing can be defined as any fishing activity breaking fisheries laws or occurring outside the reach of laws and regulations.

Within a country’s jurisdiction (i.e. territorial waters and Exclusive Economic Zone – EEZ), illegal fishing is performed by vessels fishing without permission of the coastal state (poaching) or without complying to the delivered fishing licence (e.g. fishing outside of the fishing season, harvesting banned species, using banned gear, catching more than the allowed quotas)4. Almost 90% of fishing activity occurs within a country’s jurisdiction 5, where regulations often exist but enforcement may be poor, enabling illegal fishing to occur.  
Unreported catch includes unreported, misreported, or under-reported fishing 4. Not all catches that areunreported are illegal. In many cases, small-scale artisanal fisheries do not declare their catches simply because there is no legal mandate to do so or reporting systems are lacking 6,7. Unregulated fisheries occur in areas or for fish stocks for which there are no applicable conservation or management measures or conducted by flagless ships (i.e. a ship that has not declared the country it is operating for), preventing the regulation of their catch 4.

Leaving states’ jurisdictions and going beyond EEZs (>200 nautical miles from the shoreline) lie the High Seas, international waters known as Areas Beyond National Jurisdictions. There, a few fisheries such as tuna fisheries are managed by Regional Fisheries Management Organisations (RFMOs), while others are left unmanaged. Countries can choose to join RFMOs or sign international agreements and comply with fisheries rules. Hence, illegal fishing occurs when Parties fail to comply with the conservation and management measures of the regional fisheries bodies they joined or with the rules of treaties they signed 4. However, states are not bound by treaties to which they are not Party, hence their practices may not be considered illegal. Irrespective of the legal aspect, fishing by non-Parties is considered unregulated and/or unreported unless the non-Parties have explicitly agreed to act in conformity with the conservation and management measures of the RFMOs or international agreements 4. IUU fishing easily occurs in the High Seas where there are very little enforcement and regulations 5,8.

How can IUU fisheries happen? An example from West Africa

In West African waters, Daniels et al.  demonstrated that illicit trade in seafood products is enabled by two major channels: the use of transshipment (offloading of multiple fishing boats onto large freezer ships at-sea), and the rise of export through refrigerated container ships (84% of fish exported out of West Africa follow this way), mostly going to European markets and facing less stringent inspection and reporting than fishing vessels. Transshipment, in particular, prevents transparency and accounting for the origin of catches. Indeed, when the transfers occur on an unreported basis, IUU fish can be mixed with legal catches, so any controls at port may come too late 9.

IUU scale and cost to ecosystems, people and the economy

In 2009, one-fifth of the global fish catch was caught as IUU 10. In some regions, such as the western and central Pacific Ocean and eastern central Atlantic, IUU caught fish may constitute more than 30% of the total catch 10. A more recent study showed that 8-14 million metric tons of unreported catches were potentially traded illicitly yearly, representing a total of 9-17 billion US dollars 6. The yearly loss for the economy due to the diversion of fish from the legitimate trade system was estimated to be 26-50 billion US dollars, while losses to countries’ tax revenues were between 2-4 US dollars 6.

On top of economic losses, illicit trade in seafood products contributes to the depletion of a region’s fish catch as these catches are not accounted for during the scientific stock assessments and the consequent management actions 6. More than 85% of fish stocks are at high or moderate risk of IUU fishing 11. A studied showed that in Mexico, shrimp IUU fishing may double reported catches as nearly 50% of small-scale boats operated illegally 12. IUU fishing can have very significant effects on stocks. For instance, unreported catches of Mediterranean Bluefin tuna have significantly contributed to rapid stock declines 10. It is also estimated that actual shark landings are three to four times higher than reported catches, driven by the shark-finning trade 13.

IUU fishing also threatens the food security and livelihoods of fishing communities 14. In Somalia, where foreign fishing has increased more than twenty-fold since 1981 15, foreign IUU fishing is directly competing with the domestic fishery; through links to piracy, illegal and destructive bottom trawling, contributing to regional political conflict over vessel licensing, and reducing long-term livelihood security 15.  Finally, IUU fishing vessels are major enablers of human rights abuses and have been linked to organised crime and modern slavery 16,17.

Fighting back IUU fishing

To fight back IUU fishing, the EU, through its European Commission Control 18 and IUU Regulation 19 have instated required catch certificates stating the origin of all fish and fish products traded within the European Union, one of the biggest seafood consumer. In 2016, the international Agreement on Port State Measures to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing 20 entered into force, with 66 signatory Parties but still without the participation of big fishing nations such as China and Spain. While international and regional agreements exist to counteract IUU fishing 18–20, enforcement, as well as increased transparency and accountability in supply chains, are urgently required to reinforce the fight against IUU 6.

Consumer awareness regarding the vulnerability of fish stocks has also grown, with the development of eco-labels by organizations such as the Marine Stewardship Council (MSC), despite concerns of mislabelling 21. Advances in science and technologies such as gene-associated markers 22 may now improve stock assignment and help fight again illegal fishing and mislabelling worldwide. Some fishing vessels can now be tracked down in near real-time, thanks to efforts from the Global Fishing Watch 23, although more than a third of vessels in international waters were found not to have their Automatic Identification Systems on, preventing their detection 24.

In a world where seafood commodities are increasingly being consumed and fished in an unsustainable manner, addressing Illegal, Unreported, and Unregulated fishing is an urgent matter. While countries are often reluctant to discourage fishing effort to avoid short-term losses to the local fishery economy, addressing IUU fishing may reduce the total fishing effort, regenerating fish stocks without harming the economy. An empirical example from Indonesia illustrates that the country’s efforts to curtail IUU fishing generated a 14% increase in legal catch and a 12% increase in profit while reducing the total fishing effort by at least 25% 25.

In 2015, the United Nations set the target of ending IUU fishing by 2020, as a part of the Sustainable Development Goals 26. This important target won’t be met, and Illegal, Unreported, and Unregulated fishing remains for now a major threat to marine biodiversity, preventing the sustainable exploitation of our ocean. 


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