Only a tiny fraction of Atlantic sharks – under 1% – are under protection even though most shark species are heading towards extinction, a report warns on Tuesday.

Officials from 48 Atlantic fishing countries are meeting in Istanbul this week to try to protect bluefin tuna, swordfish and other large fish. But existing conservation efforts are only saving a tiny proportion of sharks, the report from the Oceana conservation group said. "It's just the tip of the iceberg, and there are a lot of shark species, many of them vulnerable species, that are still being caught and killed," said Elizabeth Griffin Wilson, a senior scientist at Oceana. Conservation groups at the International Commission for the Conservation of Atlantic Tuna meeting are pushing for a ban on the catch of porbeagle and silky sharks – which are at extreme risk – as well as catch limits on other species such as the shortfin mako shark. Three quarters of the wide ranging shark now being caught in the Atlantic are under threat, the report said. But Iccat countries to date have only limited protection for specific shark species such as the bigeye thresher, hammerhead and oceanic whitetip sharks. There are no limits on the fishing of 15 Atlantic shark species even though some – such as the silky shark – are close to extinction. Conservationist groups hope the Istanbul meeting will build on recent momentum on shark conservation. The White House on Monday sought the Senate's approval for a new international treaty that would make it easier for countries to crack down on any illegal catches being brought to port. The state of Florida is expected to adopt new protection measures this week. The European Union last week banned all fishing for porbeagle shark in the Atlantic and Mediterranean. But it is a race against time. Sharks were not built for reproduction. They can take take years to reach sexual maturity, and produce only a few pups. And highly mobile animals are notoriously difficult to protect. "You just can't manage them one country by one country because they cross international boundaries," Wilson said. Atlantic fishing countries reported catching more than 68,000 tonnes of shark in 2009, or more than 1.3 million animals. Most were caught inadvertently by vessels targeting tuna and other fish. Populations of some species, such as the porbeagle, which are caught for their meat as well as their fins, have fallen by 99% since the middle of the last century. Scientists for the International Commission for the Conservation of Atlantic Tuna estimate it could take up to 34 years for populations to recover – even with the new EU protections. "Fishing of porbeagle sharks continue in Canadian waters", Wilson said. Three other shark species are also at high risk: silky sharks, shortfin mako, and blue sharks, the report said