Illegal, unreported and unregulated (IUU) fishing is valued to strip between $10 billion and $23 billion from the global economy, and their impacts undermine the way fish stocks are managed to make it a double concern around the world, FAO estimated.

According to the latest information released by the Food and Agriculture Organization of the United Nations (FAO), a growing number of countries are ratifying an international agreement to combat illegal fishing which will bolster inspections and crack down on lawbreaking ships responsible for up to 15 percent of global seafood output.

To help tackle the problem, FAO brokered the adoption in 2009 by its Member countries of the Agreement on Port State Measures to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing.

The agreement comes into force when 25 countries have deposited their instrument of ratification, known as acceptance of accession; so far, 12 countries have done so, the latest being Iceland in June. Two more states will soon join them.

"Port state measures" generally refer to actions taken to detect illegal fishing when ships come to port.

The Agreement promotes collaboration between fishermen, port authorities, coast guards and navies to strengthen inspections and control procedures at ports and on vessels. Importantly, it also allows states to prevent the landings of catches derived from IUU fishing by vessels regardless of the flag they fly.

Illicit fishing, which includes operating without authorization, harvesting protected species, using outlawed fishing gear and violating quota limits, may account for up to 26 million tonnes of seafood a year, more than 15 percent of the total global output. Besides economic damage, it poses risks to local biodiversity and food security in many countries.