Norway's fleet has killed more than 150 minke whales this year
Norway's annual hunt of minke whales could cost the Scottish economy up to £15m, a conservation group has claimed.
World Society for the Protection of Animals (WSPA) said whales which live and breed in Scottish waters were in long-term danger from hunting.
The charity said the practice could threaten the viability of Scotland's whale-watching industry.
The claim coincides with the latest meeting of the International Whaling Committee in Madeira.
Norway was awarded a 2009 whaling quota of 885 minke whales and has, so far, killed more than 150 this year.
WSPA is calling on the IWC to develop and promote mandatory international standards for whale watching industries, to ensure they are both sustainable and humane.
The charity said that anyone could set up a business, with no knowledge and sometimes no concern for marine mammal welfare.
Leah Garces, WSPA international director of programmes, said: "We firmly believe that whale watching is more economically significant and sustainable to people and communities than whaling.
"Research into the growth of the global whale-watching industry estimates it to be a $1.25bn business enjoyed by over 10 million people in more than 90 countries each year."
The last report on whale-watching in Scotland in 2001 estimated it was worth £7.8m per year.
WSPA said that since then the number of wildlife tourism boat operators in Scotland had doubled.
The charity's call for reform is being backed by the naturalist Terry Nutkins.
The former BBC presenter went to the Isle of Mull last week in search of minke whales with the expert Sea Life Surveys crew - a member of the not-for-profit organisation Wild Scotland group.
Mr Nutkins said: "When you see these magnificent creatures in the wild, especially in such beautiful settings, it's shameful to think that humans hunt them for profit.
"Countries like Norway could compassionately reap more profit by developing their whale-watching industry instead of whaling."
Caroline Warburton, manager of the ethical holiday association, Wild Scotland, said there was now a flourishing industry in whale watching.
"Interest in wildlife-watching has grown significantly over the past 10 years as more people realise what special wildlife we have right here on our doorstep," she said.
"Over the years, we have realised that the west coast of Scotland is an important area for whales and dolphins and livelihoods are now dependent upon whale-watching activities.
"Responsible whale watching provides a real alternative to whaling and that's why we support WSPA when they call on the IWC for an end to whaling."