“Sally sells seashells by the seashore.” Say that five times fast and then think about this: picking up seashells down by the seashore (or selling them, for that matter) is actually messing with your favorite beach’s ecosystem.

If you're planning one last trip to the beach before the little ones go back to school this fall keep this in mind:

You might have thought you were simply picking up a free souvenir when you plucked that seashell out of the surf last summer, but the cost for the environment ends up being much greater than you might have anticipated.

According to research that has been conducted over the last 30 years, researchers have found that taking shells away from beaches damages ecosystems and puts living organisms that rely on those shells for food and shelter at risk.

Beaches that were most popular with tourists were those that were most affected by seasonal seashell scavengers (try saying that five times fast!). One beach in Spain saw their number of seashells decline by 60 percent over the years, and that’s just because tourists constantly picked up shells and brought them home.

Don’t be one of those seashell scavengers and leave the shells for the fishes (or crabs, or whatever goes in them). You wouldn’t want someone stealing the windows off your house or the Oreos out of your cabinets, so why should the residents of the ocean have to lose their shells for you?