It says regulating the industry does not necessarily mean any more whales will be killed.
But it says conservation does mean regulating how or whether whale populations are exploited, one way or another.
Other conservationists sometimes say privately that limited commercial whaling may be necessary to prevent an explosion of illegal catches beyond the commission's control.
In July 2001, WWF, the global conservation campaign, which also opposes whaling, told BBC News Online a limited hunt might be the only way to prevent a free-for-all.
The commission's 2003 meeting in the German capital, Berlin, runs from 16 to 20 June. It is not expected to agree to end the moratorium on commercial whaling in force since 1986.
Two members, Japan and Norway, each continue to catch 6-700 whales a year
despite the ban.
Norway can continue whaling because it objected to the moratorium when it was agreed.
IWC meetings are usually little more than ritual confrontations between supporters and opponents of whaling.
Japan and Norway say there are enough whales of several species to support an annual catch. They say the commission, established to conserve whaling, should bow to science and lift the moratorium.
But there is still a narrow majority of members insisting the whales' recovery from centuries of mass slaughter is too precarious to allow a commercial catch, apart from their other objections.
Most see the IWC as a forum for protecting the whales, not the industry
that drove them to the brink.
"It includes regulating the exploitation of populations, which may mean simply no whaling."
He says conservation also includes the setting-up of whale sanctuaries in which no exploitation is permitted.
Mr Papastavrou said the commission had begun as a club for whalers, but was developing into a much more broadly-based conservation body.
There will be an attempt at the meeting to set the IWC on a new course with the launch of the Berlin Initiative, a way to break the sterile deadlock of the last few years.
Backed by 19 IWC member states and more than 40 non-governmental organisations, the initiative would give the commission a role in protecting all cetaceans (whales, dolphins and porpoises) against a range of threats.
These include pollution, climate change, undersea noise, entanglement in fishing nets, and collisions with shipping.
Mr Papastavrou said the initiative, if agreed, could "change the mindset" of the IWC. It could also change the perception of the commission as "something stuck in a logjam, not doing anything, because it is doing a lot on a range of issues".
He said Ifaw was concerned to have found meat from protected whale species on sale in Japanese markets. Between autumn 2002 and spring 2003, Ifaw collected 88 meat samples, and subjected them to DNA analysis.
This showed six were from humpback whales, protected since 1966. One sample was from a fin whale, last caught by Iceland in 1989 and not exported to Japan after 1991.
In 1999, Ifaw found meat from a western Pacific grey whale on sale in Japan: no more than 100 or so are thought to survive.
Iceland will prompt debate at the meeting with its plans for an annual
catch of 50 sei whales, 100 fins and 100 minkes.