Cathay Pacific has been criticised by green groups for failing to implement a ban on unsustainably sourced shark fin, almost 10 months after announcing its introduction. The airline - widely praised by environmentalist groups last September for taking what was then seen as a pioneering step - planned to bring in the ban at the start of 2013. Yesterday a spokesman for Cathay said the airline would consider an outright ban if they prove unable to define what is sustainable shark fin. Other airlines have since introduced outright bans or suspended all cargos until partial bans are in place. But Cathay Pacific has continued carrying shark fin, albeit in drastically reduced quantities following global publicity over their new policy. The airline carried less than three tonnes of shark fin from October 2012 to March 2013 compared to around 300 tonnes a year previously. Green groups insist there is no such thing as sustainable shark fin and the world's biggest sustainability verification body, the Marine Stewardship Council (MSC), has yet to certify any fishery engaged in shark finning. Cathay Pacific's head of environmental affairs Mark Watson said Cathay Pacific was using the MSC as "one source of independent verification" but was seeking advice from other experts to draw up its own sustainability guidelines. "We are working with experts identified by the International Union for Conservation of Nature (IUCN) to identify countries which meet 'best practice' in fisheries management, consistent with the principles of sustainability specifically for shark species That work is on-going ," he said. "Our goal is to arrive at a list of sources of sustainable shark products, so we can proceed with implementing our policy," said Peter Langslow, General Manager of Cargo Services for Cathay Pacific. "The very small amount (of shark fin) that we are carrying at present is from countries where fisheries are carefully regulated. Also the whole shark is landed, with fins exported as a by-product." Cathay still believe "strongly" in the concept of sustainable development according to Langslow, and are working with environmental groups such as IUCN to shape their policy. "If we are not convinced that this is a realistic or practical ambition then we will have to consider implementing an outright ban," said Langslow. Alex Hofford of NGO MyOcean, who has led a campaign by some 60 green groups to stop airlines carrying shark fin into Hong Kong, is unimpressed by the rate of decrease in shark fin cargo. "Three hundred tonnes down to three tonnes is fine but have you ever seen what three tonnes of shark fin looks like? It's still too much," he said. "The truth is that shark finning is not sustainable and most catches cannot be verified so Cathay Pacific should end all transport of shark fin," Hofford added. Where other airlines stand Qantas: All shark fin banned in June. "The restriction has been put in place to avoid participation in the supply chain of shark fins that have been sourced through the unacceptable process of finning." Air New Zealand: Total ban from June after a review. "Given ... the difficulty of confirming whether the source is sustainable or not, the decision has been taken to no longer accept shark fin for carriage." Korean Air: Total ban on all shark fin introduced in March. "There has been a series of global movements calling to ban the carriage of shark fins. In view of these movements and in order to support the global call of protecting endangered shark species, Korean Air has recently reviewed its policy." Fiji Airways: Ban on shark fin from unsustainable and unverified sources from June. All shipments suspended until definition of sustainable sources is reached. "We understand the sensitivity and importance of this matter … We won't carry shark fins until we're confident we have an independent, verifiable process in place."