Aquaaaaaaaatic Biologists are studying about invasive species and they found out that they are dangerous or they could be harmless. An invasive species is a plant plantppor animal that is not native to a specific location. Invasive species harm natural resources like the "ecosystem". The ecosystem is a community of organisms. The ecosystem is almost EVERYWHERE. Many invasive species depend on the ecosystem but they harm it too. That's why you see dead fish in lakes. I hope you learn more about the ecosystem. It is also important to people and animals. See this website that the aquatic biologists made to learn more: http://www.aquaticbiologist.com..