An international plan agreed a decade ago to protect sharks does not appear to be halting their decline, a report has warned.
Campaigners said almost a third of shark species are threatened or near threatened with extinction, largely due to fishing.
Up to 73 million sharks are caught each year, primarily for their fins, which are used to make shark fin soup.
The study by the wildlife monitoring network Traffic and the Pew Environment Group found that only 13 of the top 20 shark-catching countries had national action plans for managing and conserving their shark fisheries.
National plans of action to protect sharks were one of the main recommendations of the international scheme approved by members of the UN Food and Agriculture Organisation (FAO) in 2001.
The top 20 nations catch more than 640,000 tonnes annually, with Indonesia, India, Spain and Taiwan leading the way and taking 35% of the total catch between them.
The UK is in the top 20 but takes just 13,356 tonnes of sharks a year on average, or 1.6% of the total, and has a national conservation plan.
The report raised concerns that shark fisheries were likely to be well managed in only a few of the top 20 fishing nations, and that although national plans were in place there was no evidence to suggest they were leading to effective management of fisheries.
The study, released ahead of a meeting at the end of the month of the UN FAO’s committee on fisheries, said the top 20 nations needed to take steps including putting in place better measures to prevent sharks being caught as “bycatch” in other fisheries.
And some should take other steps including urgent assessments of shark fisheries, prohibiting the targeting of sharks by vessels on the high seas and implementing and extending regulations to require sharks be landed with their fins attached.