There are many people who promote and agree with whaling, and there are also many people who disagree with whaling. Japan, as a government, promotes whaling. (There are lots of Japanese, as an individual who disagree with whaling too.) What are their claims and where is the point? and what is the problem?
Whaling has started in the prehistoric times, thousands of years ago. We have hunted whales for its meat and oil. At the time, the whaling didn't cause serious impact to the oceanic ecology. But resent whaling has altered them because of increasing in demand of whale oil in the 19th century and increase in demand in whale meat in the 20th century. http://en.wikipedia.org/wiki/Whaling (Wikipedia) http://www.whaling.jp/qa.html (日本捕鯨協会)
Probably, the biggest issue is whether the population of the whales is increasing or are they extincting?
The answer to this question can't be answered easily. There are 84 kinds of whales, and since there are some species of whales that is increasing and there are other species that is decreasing, saying "Killing whales is bad thing because whales are endangered," is quite a out of the question. That is why someone have to research their population. People who don't want to admit even the research whaling doesn't even have their ground.
prehistoric time : 有史以前 endangered : 絶滅寸前の ground : 根拠