Walking down the beach you see the perfect shell. You pick it up, put it in your pocket and decide to keep it to remind you of your trip to paradise. While different agencies, states, and countries have specific regulations on taking shells, vials of sand, or any other object from its natural environment, you are generally not allowed to bring these souvenirs home with you, especially to another country. Why? Mainly because if everyone did it, there would be none left. But despite airports seizing tons of shells each week, seashells are still disappearing at various tourist locations and according to a new study, as global tourism increases, human-induced seashell loss may harm natural habitats worldwide.