By Simon Akam

FREETOWN (Reuters) - Nine of the 10 vessels believed to be responsible for the bulk of more than 250 reports of illegal fishing off the coast of Sierra Leone are cleared to export their catches to the European market, an environment watchdog group has found.

Illegal fishing is rampant in West Africa's Gulf of Guinea where impoverished coastal nations with little capacity to police their waters lose up to $1.5 billion in annual income to ships operating in protected zones or without proper licenses.

The European Union has set up regulations to prevent vessels involved in so-called illegal, unreported and unregulated (IUU) fishing from accessing European markets.

An 18-month investigation conducted by the Environmental Justice Foundation (EJF), however, documented a long list of abuses including fishing inside exclusion zones, using banned equipment, and transshipping fish illegally at sea.

The majority of cases involved ships accredited to sell their seafood at EU ports.

"As the world's largest importer of fish, the EU has a crucial responsibility to combat IUU fishing around the world," the report by the British-registered charity said.

"The lack of communication and coordination between the EU and coastal states in West Africa means that there is a vacuum of information on what is happening in the area with the highest levels of IUU fishing in the world."

FLAGS OF CONVENIENCE

EJF, which carried out surveillance in conjunction with 23 local communities in southern Sierra Leone, said ships refused to pay fines, covered identification markings, bribed officials and fled to neighboring counties to avoid sanctions.

It said many also sailed under so-called flags of convenience. The report says events last year exposed a problematic system under which ships' flag states, many of whom have no effective oversight of vessels, were given the primary responsibility for verifying whether catches were legitimate.

"Following the submission of evidence gathered at sea by EJF, 1,100 tonnes of fish were seized in March 2011 in Las Palmas and held for four months whilst an unprecedented international investigation was carried out," the report said.

"Crucially, the seafood in question was eventually released when the flag states involved declared the catches were legal."

Oliver Drewes, spokesman for European Fisheries and Maritime Affairs Commissioner Maria Damanaki, said the EU was "very, very concerned" about the possibility that illegally fished seafood could be making its way onto the plates of European consumers.

"We acknowledge and accept that the EU is a potential marketplace for these products," he told Reuters, adding that, if the abuses were confirmed, the offending vessels would be banned from exporting to the EU and barred from European ports.

"In practice, this is a blacklist. Once you're on that list as a vessel, you have to cease your activities," he said.

Sierra Leone's fisheries minister, Soccoh Kabia, said on Wednesday he had not yet read the EJF report but called illegal fishing an unacceptable practice regardless of the eventual destination of the catch.

"If it goes to the EU it is particularly painful," he told Reuters. "I know the EU nations as nations that comply with the law."

(Editing by Joe Bavier and Alison Williams)