Why do creationists carbon-date marine animals?
The simple answer is because the people trying to spread Creationism are intentionally lying (they can’t be doing anything else at this point, given the rabidity with which the scientifically minded have pointed out the error), and the people who follow them are foolish enough not to do the research. Wait and see. I’ll be amazed if someone doesn’t come up with that stupid dinosaur bone “study” or try to claim diamonds can be carbon dated. Come to think of it, I think I’m more dumbfounded by the fact Creationists will use the reservoir effect to claim carbon dating doesn’t work in one breath, and then turn around and claim that the erroneous carbon dating results they’ve gotten from their botched experiments on shellacked bones and diamond dust proves the world is only 6,000 years old.