The scientist was correct in saying that the Blue Whale would need to be on the ark.
Biblical creationists also claim that continental drift does not occur and that the Earths geological features are artefacts of the flood. This would mean that the water would have contained so much sediment that the oceans would have had the consistancy of mud, therefore whales, fish etc would be unable to live in the flood waters.
Even without the sediments, half the worlds fish would need to be on the ark as some fish require salt water, some fresh water - which were the floods waters?
The book 'Telling Lies for God' by Ian Plimer has an excellent chapter pointing out all the scientific errors in the flood story, check it out if you can find it.
SOME people claim. Always remember the "some". Some believe it was more local than the text implies. Some believe the whole thing is an allegory. The joke was clearly predicated on the standard "Let's not mess with our suspension of disbelief" regular folk version, not the "Let's figure out how to make this theoretically possible" apologists' version.