To study the impact of a nonnative species on an ecosystem you first need to establish a baseline. Watch biologist Chase O'Neil pull apple snails from the waterway of a South Florida ranch that is experiencing an apple snail invasion. After the snails are captured they're numbered so they can be counted, divided, and later measured. Fortunately it took more than just two scoops of a net to capture this many snails, but their presence is still very much unwelcome. | University of Florida Institut