In addition to cruelty, the replacement of whale products, meat toxicity issues, and conservation, fellow SciBling the Island of Doubt brings up another great point against whaling:
For more than a decade now, genetic analysis of whale meat on Japanese markets has shown evidence of widespread fraud. The simple truth is, unlike pork and beef, it’s not so easy to tell the meat of one species of whale from another, a situation that allows whalers to catch just about anything from the order cetacea, and call it whatever the law allows them to catch.
Remember that whaling is an opportunistic method of obtaining food — whalers are sorely tempted to harpoon whatever comes along, rather than wait for the right species. And of course, catch and release is not an option.
It turns out that this is exactly what the genetic analysis in Japan has shown has been going on for years. A significant proportion of the whale meat on sale in Japan comes from endangered populations.
Check out his entire post, here.