By Richard Black
Environment correspondent, BBC News, Madeira
A clause in the convention means countries can hunt whales for research
The outgoing chair of the International Whaling Commission (IWC) has suggested whale conservation could benefit from ending the commercial hunting ban.
Dr William Hogarth's remarks came at the end of this year's IWC meeting, which saw pro- and anti-whaling nations agree to further compromise talks.
A Greenpeace spokesman said the moratorium had to stay intact.
The meeting deferred a decision on a controversial bid from Greenland to add humpback whales to its annual hunt.
The Greenland Inuit are one of the indigenous peoples granted hunting quotas because they are deemed to need whalemeat.
The meeting wrapped up a day ahead of schedule, although a small group of delegates convenes on Friday to start planning a second year of talks about a possible compromise deal between the various blocs.
The first year's discussions were supposed to reach a deal by this meeting, but the deadline proved too tight.
The 1982 commercial whaling moratorium is one of the conservation movement's iconic achievements, and environment groups and anti-whaling nations are, at least on the surface, lined up four-square behind it.
But Dr Hogarth, a US fisheries expert who led the compromise talks for the last year, suggested it could now be a problem for whale conservation.
"I'll probably get in trouble for making this statement, but I am probably convinced right now that there would be less whales killed if we didn't have the commercial moratorium," he told BBC News immediately after the meeting ended.
His argument is that Japan's hunts, conducted under a clause in the whaling convention that gives any country the right to hunt as many whales as it wants for scientific research, are essentially unregulated.
Currently Japan catches more than 1,000 whales each year; and Dr Hogarth believes use of the scientific whaling clause encourages large hunts in order to get enough samples to draw scientifically valid conclusions.
"I'm not sure you'd need nearly so many whales if it were strictly for sustainable use," he said.
The key, he suggested, was to find a way of allowing limited, tightly regulated small-scale whaling for local consumption, while outlawing large-scale, heavily commercial hunts and keeping international trade under control.
The Japanese delegation has kept a low media profile during this meeting, but it is likely that Dr Hogarth's words will be well received in Tokyo as it seeks to win international agreement for introducing "small-type coastal whaling" as part of a compromise deal.
How it goes down with environmental groups is another matter.
Greenpeace oceans campaigner John Frizzell, a long-time opponent of whaling, said the moratorium had to stay.
"Lifting the commercial moratorium would be an extremely bad idea," he said.
"Before the moratorium, under the IWC's guidance and supervision, populations were driven down to commercial extinction one after the other and heavily depleted.
"The moratorium is the only management procedure that has even halfway worked, and to talk about scrapping it is going back to the old days."
Privately, some anti-whaling campaigners may be prepared to countenance a partial end to the moratorium, with strict regulations placed on catch quotas, trade and monitoring, in return for bringing scientific whaling under the IWC's control.
Sue Lieberman, head of the global species programme at WWF International, said that although Japan was not currently offering to end scientific whaling within a timeframe of a few years, progress was possible in the longer term.
"I don't think anyone should expect Japan to come forward and say 'you're right, we've been wrong all these years, we give up'," she said.
"But I think it's important to sit down with Japan and talk about it.
"It is time to give it up. Economically it makes no sense, it's not necessary for food security, it's time to leave the Southern Ocean [whale] sanctuary as a sanctuary - and I hope politically Japan will understand that."
The meeting's other potentially contentious issue - Greenland's request to add 10 humpback whales per year to the minkes, bowheads and fin whales that the Inuit already catch - was left open after EU nations could not agree a position among themselves.
THE LEGALITIES OF WHALING
Objection - A country formally objects to the IWC moratorium, declaring itself exempt. Example: Norway
Scientific - A nation issues unilateral 'scientific permits'; any IWC member can do this. Example: Japan
Aboriginal - IWC grants permits to indigenous groups for subsistence food. Example: Alaskan Inupiat
EU policy is to vote as a bloc in all international environmental agreements.
But here there was an unbridgeable split between those such as the UK who found the detail of Greenland's proposal unacceptable and others who favoured approval.
With the EU commanding so many votes in the IWC as to hold the balance of power, the option of deferring a decision, awaiting research into how much meat Greenlanders obtain from whales, poured diplomatic oil on troubled waters.
But it did not find favour with Amalie Jessen, Greenland's deputy minister for fisheries, hunting and agriculture.
"I don't think EU countries understand the needs of traditional hunters," she said.
"I have observed very little tolerance and very little understanding of our situation, and they are always coming up with new requests and questions and conditions."
Greenland's request was turned down at the last two IWC meetings, and the government cites the issue as a reason for wanting to move its whaling outside the commission's remit.
Away from these main issues, environmental groups were pleased to see the passage of a resolution noting that climate change will affect cetaceans, and appealing to IWC members to "take urgent action to reduce the rate and extent of climate change".
Environmental lawyers said this could be a precedent for regional fisheries management organisations, which normally shy away from discussion of climate issues.
There was also appreciation for Australia's initiation of a new research partnership in the Southern Ocean that will use exclusively non-lethal methods.
Although comment on Japan's research in the same region tends to focus on the lethal aspects, its fleet also carries an international team of scientists that documents whale numbers by sightings and other techniques.
A long-time contention of some observers has been that if countries such as Australia want Japan to stop its expeditions, they have to start funding an alternative research operation - and now that message appears to have been heard.
With Dr Hogarth's departure, the job of steering next year's negotiations between Japan and anti-whaling countries such as Australia falls to incoming chairman Cristian Maquieira, who said that on a scale of difficulty from one to 10, this was "about a 12".
"Speaking candidly, it's an organisation that has no carrots and no sticks," he said.
But the Chilean diplomat was optimistic about the negotiations
"I feel if there's one common element involved here, it's that everybody believes the status quo is no longer acceptable," he said.