yeah I just had a look at wikipedia and it said there are 105,000 of them out there, so I'd say it can definitely be sustainably harvested. I guess what pisses me off isn't that they're killing whales if those whales aren't an endangered species, its the excuse that its for science.
The problem with any form of seafood harvesting is making sure people stick to quotas etc, so flat out banning whaling protects them whereas if you said you can catch 500 a year or whatever, it'd be relatively easy to just overdo it and fudge the numbers.